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China wants to become a science, technology, and manufacturing superpower by upgrading and modernizing its industrial base and concentrating the nation’s innovation resources around strategic priorities. However, in this policy brief, Jeroen Groenewegen-Lau, head of the Science, Technology and Innovation program at MERICS, argues that it is difficult for the state to integrate innovation resources because of the gap separating universities and research organizations from industry, which impedes the translation of scientific output into technological prowess. By contrast, Beijing has been much more successful at directing industrial development. As a result, he says, achieving a modernized industrial base is now the dominant framework for Chinese policymakers as they pursue technological self-reliance.

PURPOSE Continuity of care is broadly associated with better patient health outcomes. The relative contributions of continuity with an individual physician and with a practice, however, have not generally been distinguished. This retrospective observational study examined the impact of continuity of care for patients seen at their main clinic but by different family physicians. METHODS We analyzed linked health administrative data from 2015-2018 from Alberta, Canada to explore the association of physician and clinic continuity with rates of emergency department (ED) visits and hospitalizations across varying levels of patient complexity. Physician continuity was calculated using the known provider of care index and clinic continuity with an analogous measure. We developed zero-inflated negative binomial models to assess the association of each with all-cause ED visits and hospitalizations. RESULTS High physician continuity was associated with lower ED use across all levels of patient complexity and with fewer hospitalizations for highly complex patients. Broadly, no (0%) clinic continuity was associated with increased use and complete (100%) clinic continuity with decreased use, with the largest effect seen for the most complex patients. Levels of clinic continuity between 1% and 50% were generally associated with slightly higher use, and levels of 51% to 99% with slightly lower use. CONCLUSIONS The best health care outcomes (measured by ED visits and hospitalizations) are associated with consistently seeing one's own primary family physician or seeing a clinic partner when that physician is unavailable. The effect of partial clinic continuity appears complex and requires additional research. These results provide some reassurance for part-time and shared practices, and guidance for primary care workforce policy makers. https://doi.org/10.1370/afm.3107, INTRODUCTION The ideal provision of primary care is based on a longitudinal relationship between a patient and a family physician (FP), referred to as relational continuity. (1) Research has shown [...]

There is great variation in the experiences of Latine/e/x/o/a, Hispanic, and/or Spanish origin (LHS) individuals in the United States, including differences in race, ancestry, colonization histories, and immigration experiences. This essay calls readers to consider the implications of the heterogeneity of lived experiences among LHS populations, including variations in country of origin, immigration histories, time in the United States, languages spoken, and colonization histories on patient care and academia. There is power in unity when advocating for community, social, and political change, especially as it pertains to equity, diversity, and inclusion (EDI; sometimes referred to as DEI) efforts in academic institutions. Yet, there is also a critical need to disaggregate the LHS diaspora and its conceptualization based on differing experiences so that we may improve our understanding of the sociopolitical attributes that impact health. We propose strategies to improve recognition of these differences and their potential health outcomes toward a goal of health equity. https://doi.org/10.1370/afm.3103, INTRODUCTION In this paper, Latine/e/x/o/a, Hispanic, and/or Spanish origin (LHS) family medicine faculty experts in equity, diversity, and inclusion (EDI; sometimes referred to as DEI) come together to unmask the [...]

I was recently diagnosed with prediabetes, based on slightly elevated glycemia and no other risk factors. To allay my confusion and anxiety, I applied my epidemiology and health services research [...]

Academic practices and departments are defined by a tripartite mission of care, education, and research, conceived as being mutually reinforcing. But in practice, academic faculty have often experienced these 3 missions as competing rather than complementary priorities. This siloed approach has interfered with innovation as a learning health system in which the tripartite missions reinforce each other in practical ways. This paper presents a longitudinal case example of harmonizing academic missions in a large family medicine department so that missions and people interact in mutually beneficial ways to create value for patients, learners, and faculty. We describe specific experiences, implementation, and examples of harmonizing missions as a feasible strategy and culture. 'Harmonized' means that no one mission subordinates or drives out the others; each mission informs and strengthens the others (quickly in practice) while faculty experience the triparate mission as a coherent whole faculty job. Because an academic department is a complex system of work and relationships, concepts for leading a complex adaptive system were employed: (1) a 'good enough' vision, (2) frequent and productive interactions, and (3) a few simple rules. These helped people harmonize their work without telling them exactly what to do, when, and how. Our goal here is to highlight concrete examples of harmonizing missions as a feasible operating method, suggesting ways it builds a foundation for a learning health system and potentially improving faculty well-being. https://doi.org/10.1370/afm.3108, INTRODUCTION Academic practices and departments are defined by a tripartite mission of care, education, and research, conceived as being mutually reinforcing. But in l practice, carrying out this tripartite mission [...]

PURPOSE The COVID-19 pandemic abruptly interrupted breast cancer screening, an essential preventive service in primary care. We aimed to evaluate the pandemic's impact on overall and follow-up breast cancer screening using real-world health records data. METHODS We retrospectively analyzed a cohort of women eligible for breast cancer screening through the study period from January 1, 2017 to February 28, 2022 using TriNetX Research Network data. We examined the temporal trend of monthly screening volume throughout the study period and compared the rate of adherence to follow-up screening within 24 months after the previous screening when the follow-up screening was due in the pre-COVID period vs the COVID period. To account for multiple screenings in the longitudinal data, we applied a logistic regression model using generalized estimating equations with adjustment for individual-level covariates. RESULTS Among 1,186,669 screening-eligible women, the monthly screening volume temporarily decreased by 80.6% from February to April 2020 and then rebounded to close to pre-COVID levels by June 2020. Yet, the follow-up screening rate decreased from 78.9% (95% CI, 78.8%-79.0%) in the pre-COVID period to 77.7% (95% CI, 77.6%-77.8%) in the COVID period. Multivariate regression analysis also showed a lower adherence to follow-up screening during the COVID period (odds ratio = 0.86; 0.86-0.87) and a greater pandemic impact among women aged 65 years and older and women of non-Hispanic 'other' race (Asian, American Indian or Alaska Native, and Native Hawaiian or Other Pacific Islander). CONCLUSIONS The COVID-19 pandemic had a transient negative effect on breast cancer screening overall and a prolonged negative effect on follow-up screening. It also exacerbated gaps in adherence to follow-up screening, especially among certain vulnerable groups, requiring innovative strategies to address potential health disparities in primary care. https://doi.org/10.1370/afm.3098, INTRODUCTION Breast cancer is the second most common cancer among women in the United States. (1) Every 1 in 8 women nationally will develop this malignancy in their lifetime, (1) [...]

PURPOSE The experience of ethnically diverse parents of children with serious illness in the US health care system has not been well studied. Listening to families from these communities about their experiences could identify modifiable barriers to quality pediatric serious illness care and facilitate the development of potential improvements. Our aim was to explore parents' perspectives of their children's health care for serious illness from Somali, Hmong, and Latin-American communities in Minnesota. METHODS We conducted a qualitative study with focus groups and individual interviews using immersion-crystallization data analysis with a community-based participatory research approach. RESULTS Twenty-six parents of children with serious illness participated (8 Somali, 10 Hmong, and 8 Latin-American). Parents desired 2-way trusting and respectful relationships with medical staff. Three themes supported this trust, based on parents' experiences with challenging and supportive health care: (1) Informed understanding allows parents to understand and be prepared for their child's medical care; (2) Compassionate interactions with staff allow parents to feel their children are cared for; (3) Respected parental advocacy allows parents to feel their wisdom is heard. Effective communication is 1 key to improving understanding, expressing compassion, and partnering with parents, including quality medical interpretation for low-English proficient parents. CONCLUSIONS Parents of children with serious illness from Somali, Hmong, and Latin-American communities shared a desire for improved relationships with staff and improved health care processes. Processes that enhance communication, support, and connection, including individual and system-level interventions driven by community voices, hold the potential for reducing health disparities in pediatric serious illness. https://doi.org/10.1370/afm.3106, INTRODUCTION In the United States, nearly 500,000 children live with a serious or life-threatening illness, (1,2) defined by the Institute of Medicine as those who carry a substantial probability of [...]

This study characterized adult primary care medical assistant (MA) staffing. National Survey of Healthcare Organizations and Systems (n = 1,252) data were analyzed to examine primary care practice characteristics associated with MA per primary care clinician (PCC) staffing ratios. In 2021, few practices (11.4%) had ratios of 2 or more MAs per PCCs. Compared with system-owned practices, independent (odds ratio [OR] = 1.76, P https://doi.org/10.1370/afm.3100, INTRODUCTION Medical assistants (MAs) are among the fastest growing occupations within the US primary care workforce, (1) but little is known about organizational factors associated with MA support levels for [...]

PURPOSE Despite increased clinician awareness of systemic racism, lack of substantial action toward antiracism exists within health care. Clinical staff perspectives, particularly those of racial-ethnic minorities/persons of color (POC) who disproportionately occupy support staff roles with less power on the team, can yield insights into barriers to progress and can inform future efforts to advance diversity, equity, and inclusion (DEI, also referred to as EDI) within health care settings. This qualitative study explored the perspectives of staff members on race and role power dynamics within community health clinic teams. METHODS We conducted semistructured 45-minute interviews with staff members working in community health clinics in a large urban health care system from May to July 2021. We implemented purposeful recruitment to oversample POC and support staff and to achieve equal representation from the 13 community health clinics in the system. Interviews were audio recorded, transcribed, and analyzed over 6 months using a critical-ideological paradigm. Themes reflecting experiences related to race and role power dynamics were identified. RESULTS Our cohort had 60 participants: 42 (70%) were support staff (medical assistants, front desk clerks, care navigators, nurses) and 18 (30%) were clinicians and clinic leaders. The large majority of participants were aged 26 to 40 years (60%), were female (83%), and were POC (68%). Five themes emerged: (1) POC face hidden challenges, (2) racial discrimination persists, (3) power dynamics perpetuate inaction, (4) interpersonal actions foster safety and equity, and (5) system-level change is needed for cultural shift. CONCLUSIONS Understanding the race and role power dynamics within care teams, including experiences of staff members with less power, is critical to advancing DEI in health care. https://doi.org/10.1370/afm.3099, INTRODUCTION Team-based care, established as the gold standard model for providing care more than a decade ago, (1) allows integrated clinical teams with different and complementary skills and perspectives to [...]

PURPOSE To determine the effects of stratified primary care for low back pain (SPLIT program) in decreasing back-related disability for patients with low back pain (LBP) in primary care. METHODS We conducted a before-and-after study. We compared health-related outcomes for 2 sequential, independent cohorts of patients with LBP recruited at 7 primary care units in Portugal. The first prospective cohort study characterized usual care (UC) and collected data from February to September 2018. The second was performed when the SPLIT program was implemented and collected data from November 2018 to October 2021. Between cohorts, physical therapists were trained in the implementation of the SPLIT program, which used the STarT Back Screening Tool to categorize patients for matched treatment. We compared back-related disability (Roland-Morris Disability Questionnaire, 0-24 points), pain (Numeric Pain Rating Scale, 0-10 points), perceived effect of treatment (Global Perceived Effect Scale, -5 to +5 points), and health-related quality of life (EuroQoL 5 dimensions 3 levels index, 0-1 points). RESULTS We enrolled a total of 447 patients: 115 in the UC cohort (mostly treated with pharmacologic treatment) and 332 in the SPLIT cohort (all referred for a physical therapy intervention program). Over the study period of 6 months, patients in the SPLIT program showed significantly greater improvements in back-related disability ([beta], -2.94; 95% CI, -3.63 to -2.24; P[less than or equal to].001), pain ([beta], -0.88; 95% CI, -1.18 to -0.57; P[less than or equal to].001), perceived effect of treatment ([beta], 1.40; 95% CI, 0.97 to 1.82; P[less than or equal to].001), and health-related quality of life ([beta], 0.11; 95% CI, 0.08 to 0.14; P[less than or equal to].001) compared with UC. CONCLUSIONS Patients in the SPLIT program for LBP showed greater benefits regarding health-related outcomes than those receiving UC. https://doi.org/10.1370/afm.3104, INTRODUCTION Low back pain (LBP) is a high-burden health problem worldwide, and its management represents a serious challenge for health systems. (1-4) The burden caused by LBP is mainly explained [...]

PURPOSE Procedures are manual technical skills clinicians perform for their patients. Family physicians (FPs) acquire these skills during residency; most are undertaken in outpatient settings. We performed a retrospective observational cohort study to describe the extent to which FPs perform the core procedures recommended by the Council of Academic Family Medicine (CAFM) and how this might have changed over time. METHODS The CAFM recommended a list of procedures all FP residents should perform competently after graduation. We modified this list for Medicare beneficiaries to enable matching with Current Procedural Terminology codes. We probed Medicare Part B databases for modified CAFM procedure claims submitted by FPs in 2021 and how these claims changed from 2014 to 2021. RESULTS In 2021, there were 904,278 modified CAFM procedures filed by 9,410 FPs in the outpatient setting. All procedures were clustered with respect to organ system (eg, musculoskeletal, skin, pulmonary). Beginning in 2014 and continuously through 2021, there was a 33% decrease in outpatient procedures filed and a 36% decrease in the number of FPs filing them. CONCLUSIONS Office-based procedures are integral to a primary care physician's role, although the activity is rarely analyzed. At a time when the Medicare population is growing, the number of available FPs and the number of procedures they perform are not. This decrease might result from the changing scope of FP practice, new referral patterns, task shifting, and/or increased delegation to physician associates and nurse practitioners. https://doi.org/10.1370/afm.3096, INTRODUCTION The US primary care medical workforce is changing, and modeling current capabilities to project what is needed for a more diversified workforce is improving. (1) Activities occurring in the [...]

The Chalcolithic Age (5000-3000 BCE) ([1]) is of great interest when studying archaeometallurgy. Stone workers, who for millions of years provided tools for survival and weapons of war, beautiful decoration [...]

Martempering involves cooling steel from the aus-tenitizing temperature and rapidly cooling into either specially formulated petroleum oil or a molten salt bath with a specific composition to a temperature slightly [...]

There are many industrial processes that require intimate contact between an alloy and a corrosive gaseous environment at high temperatures. The alloys used under these conditions are designed to form [...]

Artificial intelligence (AI) and machine learning (ML) are advancing at a rapid pace and having an ever-larger impact on our daily lives. Equally so, AI and ML are increasingly affecting [...]

The ASM Board of Trustees, Executive Director, and other members of the ASM staff, gathered on July 25, 2023 for the annual strategic planning session. The 2020-2025 plan was reviewed, [...]

This archaeometallurgical article describes the study of a 5-peseta Spanish silver coin minted in 1870 (Fig. 1). The objective of this research is to metallographically study this piece that belongs [...]

The quest for extreme applications of materials inevitably leads to the development of extreme materials. Metallic glasses are non-crystalline solid metals that have high strength, excellent corrosion resistance, and impressive [...]

Digital light processing (DLP) based three-dimensional (3D) printing technology which uses photocurable resin has been a center of interest due to its printing accuracy and printing speed. In our research, we have synthesized and modified the bisphenol A-based epoxy acrylate resin for the DLP 3D printer having a printing accuracy of 50 [micro]m. As the viscosity plays an important role in printing accuracy, the resin was modified with mono-functional, di-functional, tri-functional, and combination of di-tri functional acrylate diluents as well as with photoinitiator to achieve the desired level of viscosity. The process parameters like curing time and intensity were optimized using the DLP 3D printer. The uncured and UV-cured samples were characterized using FTIR-ATR, [sup.1]NMR, UV-VISIBLE, and TGA techniques. The analysis of the uncured and UV-cured samples was carried out using viscosity, gel content, water absorption, and chemical resistance test. The mechanical properties of the UV-cured samples were determined using hardness and tensile strength test. The 3D-printed samples were observed under high-resolution microscope to confirm the printing quality and resolution. The resulting outcome confirmed that the proper selection of diluents is an important parameter for achieving the good quality and resolution of samples printed using the DLP 3D printer technology. Highlights * Synthesis and modification of UV-curable resin * Selection of diluents for controlling the processablility of UV-curable resin * Optimization of process parameters for DLP based 3D printer * 3D printing of samples having good quality, resolution and feature size. KEYWORDS 3D printing, diluents, DLP, epoxy acrylate, photoinitiator, 1 | INTRODUCTION Additive manufacturing (AM), also known as threedimensional (3D) printing refers to a class of techniques that is used to fabricate parts through adding materials via layer-by-layer using [...]

In this work, the oxygen barrier property of polyethylene terephthalate (PET) films was enhanced by optimizing the 'active' and 'passive' synergistic barrier approaches, that is, integration of high barrier material polyethylene naphthalate (PEN) and oxygen scavengers along with catalyst with PET before biaxially stretching the PET blended films. When the PEN content in the PET blended films reached 50wt%, the oxygen permeability coefficient was significantly reduced to 0.9687 cc*mil*[m.sup.-2]*[day.sup.-1] 0.1 [MPa.sup.-1], showing an enhancement of 117.4 times compared to the pure PET film. Furthermore, the water vapor permeability coefficient was reduced to 8.0208 g*mil*[m.sup.-2]*[day.sup.-1], representing a 45.5% reduction in comparison to the pristine PET film. It also maintained a higher transverse and longitudinal tensile strength (110.5 and 127.2 MPa) than PET film only with oxygen scavengers and catalyst (53.5 and 78.0 MPa). This work presents a viable and practical approach to endow PET materials with simultaneously enhanced oxygen, water barrier performance, and mechanical property. Highlights * The OPC of PET film was as low as 0.9687 cc*mil*[m.sup.-2]*[day.sup.-1]*0.1 [MPa.sup.-1]. * The 'active' and 'passive' barrier techniques together reduced the OPC of PET film. KEYWORDS blow molding, oxygen barrier, oxygen scavenging, polyethylene naphthalate, polyethylene terephthalate, water barrier, 1 | INTRODUCTION Polyethylene terephthalate (PET) is widely used as a thermoplastic polyester in food packaging due to its excellent mechanical property, affordability, as well as high transparency. (1,2) Although [...]

We report efficacious vibration damping of carbon black reinforced nitrile butadiene rubber-polyvinyl chloride blend (NVC) vulcanizates in a constrained layer damping (CLD) configuration. The objective is to compare numerical simulations using finite element method (FEM) and the widely used Ross-Kerwin-Ungar (RKU) model with the experimental results. NVC blend (50:50 by weight), was compounded with carbon black as reinforcing filler and vulcanized using a sulfur-based curative system. Significant reinforcement and toughening were observed for the carbon black reinforced vulcanizates compared to the pristine blend. The viscoelastic properties of the vulcanizates were assessed using dynamic mechanical analysis (DMA), exploring their behavior concerning temperature variations and different frequencies to generate the Prony series coefficients for input in FEM analysis. Vibration damping experiments were conducted using the Oberst beam method in a single cantilever mode, with steel as the vibrating substrate, aluminum as the constraining layer, and the NVC vulcanizates as viscoelastic materials (VEM). Numerical simulations were performed using FEM to analyze mode shapes and frequency response function (FRF), and the RKU model was employed to quantify CLD system loss factors (SLF). The salient finding of this study was the observed SLF values in the range of 0.08-0.20 in the frequency regime of 200-2000 Hz. These values qualify the studied material as effective VEMs for CLD treatment of structural vibrations. This study supports design optimization efforts in a wide range of engineering applications where effective vibration damping is critical. Highlights * Enhancement of NVC blend properties through carbon black reinforcement. * Detailed analysis of viscoelastic behavior using DMA. * Validation of findings through experimental modal analysis. * Promising results in terms of system loss factors for CLD applications. KEYWORDS carbon black, constrained layer damping, dynamic mechanical analysis, finite element method, PVC-NBR blend, Ross-Kerwin-Ungar model, 1 | INTRODUCTION The issue of uncontrolled mechanical vibration is prevalent in various domains, leading to the reduced operational efficiency of instruments and creating disturbances in the work environment. While [...]

In this study, dynamically vulcanized thermoplastic elastomer nanocomposites consisting of polypropylene (PP) as the thermoplastic matrix, ethylene propylene diene monomer (EPDM) rubber as the dispersed phase, and needle-like cellulose nanocrystals (CNC) were investigated. The two polymers were melt blended in a ratio of 70/30 (PP/EPDM) and 60/40% w/w (PP/EPDM) together with CNC (2, 3, and 5 phr) and sulfur-curing system. The potential of EPDM-g-MA and PP-gMA's as interfacial compatibilizers for enhancing interfacial interactions between components and partitioning of CNC between the two polymer phases was examined by measuring the decrease in the size of EPDM particles. The resulting thermoplastic vulcanizates (TPV) were characterized using a melt rheometric mechanical spectrometer (RMS), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and tensile tests. The inclusion of any type of interfacial compatibilizers led to enhanced tensile properties when compared to the samples lacking compatibilizers in both TPVs and TPEs in different ratios. EPDM-g-MA was found to be more effective for 60/40% w/w (PP/EPDM) TPVs, while PP-g-MA showed higher potential for 70/30% w/w TPVs. The CNCreinforced TPVs displayed higher melt elasticity than their unloaded counterparts. These nanocomposites also showed reduced EPDM particle size, enhanced Young modulus, and a higher degree of crystallinity. Highlights * Nanocomposite thermoplastic vulcanizates (TPVs): polypropylene (PP)/ ethylene propylene diene monomer (EPDM)/cellulose nanocrystals (CNC) with matrix-dispersed morphology. * Interfacial enhancement: Compared EPDM grafted maleic anhydride (EPDM-g-MA) and PP-g-MA potentials. * Tensile properties: EPDM-g-MA is more effective in higher rubber content TPVs. * Mechanical enhancements: Improved properties and Young's modulus in CNC-filled TPVs. * Diverse applications: PP/EPDM/CNC nanocomposites in auto, electrical, electronic, and packaging industries. KEYWORDS cellulose nanocrystal, dynamically vulcanized, ethylene propylene diene monomer, interfacial compatibilizer, polypropylene, thermoplastic elastomer, 1 | INTRODUCTION A 'polymer blend' refers to a material resulting from the combination of two or more structurally different polymers, this blending technique, commonly employed for cost-effective enhancement of [...]

This study explores the utilization of bio-polyol, derived from castor oil modified with waste tire rubber (WTR), in the synthesis of rigid polyurethane-polyisocyanurate foams. Two WTR concentrations (10% and 20%) were incorporated, investigating their impact on foaming, cellular structure, and various foam properties. Response surface methodology assessed the influence of polyol/isocyanate ratios and WTR content on thermal, physical, and mechanical responses. Results indicated significant effects of polyol/isocyanate ratios on thermal and density properties, while WTR content exhibited an opposite trend. Mechanical behavior showed a distinct pattern compared to thermal and physical aspects, suggesting no conclusive correlation between compressive stress variability and polyol/ isocyanate ratio or WTR content. Consequently, the application of these foams depends on specific property requirements, highlighting the potential of sustainable bio-polyols and recycled WTR in replacing conventional petroleum-based counterparts in polyurethane foam production. Highlights * Development of rigid polyurethane-polyisocyanurate foams based on castor oil. * Polyurethane-polyisocyanurate foams modified with waste tire rubber. * Increased isocyanate index impacts thermal stability and density. * Response surface methodology showed variability in compressive stress behavior and the polyol/isocyanate ratio. * For application of polyurethane-polyisocyanurate foams will depend on the desired properties. KEYWORDS castor oil, response surface methodology, rigid polyurethane-polyisocyanurate foams, tire rubber waste, 1 | INTRODUCTION Improper disposal of solid waste is one of the main environmental problems currently faced. (1) With the increase in population and consumption, the amount of waste generated [...]

In this paper, a high-performance composite nanofiber membrane with excellent air filtration and dye degradation properties was prepared by incorporating MIL-53 (Fe) nanoparticles into the electrospinning solution. The results showed that the filtration efficiency for PM2.5 of the PP/FVDF-HFP/MIL-53(Fe) composite nanofiber membrane reached up to 99.3% with the addition of 2 wt% MIL-53(Fe). Moreover, the composite nanofiber membrane exhibited steady filtration efficiency across different parameters, including air velocity, PM2.5 concentration, and extended testing time. Furthermore, the incorporation of MIL-53(Fe) significantly enhanced the removal efficiency of the composite nanofiber membrane toward Rh B, resulting in a remarkable 91% removal rate. The polymer/MOF composite nanofiber membranes prepared by simple and cheap electrospinning technology have a wide range of practical applications in the field of environmental protection. Highlights * PPM composite nanofiber membrane was prepared via electrospinning method. * MIL-53(Fe) nanoparticles were introduced to PPM composite nanofiber membrane. * PPM composite nanofiber membrane showed excellent removal efficiency for PM2.5. * PPM composite nanofiber showed a good removal performance for RhB in solution. KEYWORDS air filtration, composite nanofiber membrane, dye degradation, MIL-53(Fe), PVDF-HFP, 1 | INTRODUCTION The rapid advancement of industrial emissions, traffic exhaust, and coal combustion has become increasingly prominent, resulting in a growing concern regarding environmental pollution. (1) The excessive presence [...]

Cellulose diacetate (CDA) and triacetate (CTA) were derived from Egyptian cotton to fabricate reverse osmosis (RO) membranes. The Pphase inversion method was utilized for the production of CDA-based membranes. Comprehensive characterization of these membranes involved structural, morphologial, and hydrophilic property analyses through techniques such as nuclear magnetic resonance (NMR), infrared spectroscopy, thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle measurements. NMR spectra indicated a degree of substitution of 2.9 for CTA and 2 for CDA. The resulting RO membrane demonstrated a water flux of 6.1 L/[m.sup.2]*h and a salt rejection of 90.3%. Annealing led to an enhanced top layer with reduced defects and macrovoids in the support layer. Moreover, grafting the RO membranes with 15 wt% of 2-acrylamidopropane-2-methyl sulphonic acid improved salt rejection to 96.2% and water flux to 8.7 L/[m.sup.2]*h. These findings underscore the significant performance enhancements achieved through both annealing and grafting processes in RO membranes. KEYWORDS cellulose triacetate acetate, cotton, desalination, phase inversion, sustainable, 1 | INTRODUCTION The issue of water scarcity has reached a critical level in Egypt, where per capita water availability is diminishing. (1) Additionally, the undervaluation of Egyptian cotton compounds [...]

Rapid and facile self-assembly coatings play a crucial role in surface functionalization of materials. In this study, a safe, fast, and environmentally friendly method is proposed to form a metal-phenolic network (MPN) through the assembly of gallic acid (GA) and iron ions ([Fe.sup.3+]), which is used for the in situ polymerization coating of l,3,5,7-tetranitro-l,3,5-7-tetrazacyclooctane (HMX). The surface of the modified HMX crystals become visibly roughened. Thermoplastic polyurethane (TPU) was coated on the surface of modified HMX by water suspension method to form HMX@MPN@TPU double-layer core-shell energetic composite material. Compared with the raw material HMX, the [beta]-[delta] phase transition temperature of the double-layer core-shell structure composite increased by 12.36[degrees]C, the impact sensitivity and friction sensitivity decreased, and the compressive strength increased by 38%, which effectively improved its mechanical properties. Highlights * It has been demonstrated that metal-phenolic networks can self-assemble on the surface of crystals. * A water suspension method was employed to prepare energetic material powder into a polymer-bonded explosive (PBX). * The modified PBX showed significant improvements in various properties, indicating that metal-phenolic networks can serve as excellent modifying materials. KEYWORDS bilayer core-shell energetic composite, HMX, in situ polymerization method, metal-phenolic network, 1 | INTRODUCTION Energetic materials have the advantages of high energy density, high combustion speed, and high explosiveness, so they have attracted wide attention in the military field. (1-3) Among [...]

As the demand for sustainable and environmentally conscious practices continues to grow, recycled plastics have become increasingly popular for plastics manufacturers. However, reprocessing these materials can result in inconsistencies in both process and product quality, leading to a loss in mechanical properties. To address this issue, this work investigates the injection molding of recycled and virgin polypropylene (PP). Using a multi-cavity hot runner mold, correlations between processing parameters, such as melt temperature, mold temperature, pack pressure, soak time, and mechanical properties, were systematically investigated. A multivariate analysis approach was used to model the variables for each material. Results indicated significant correlations between processing, mechanical properties, and morphology. In particular, for the PP, the melt temperature affected the formation of [beta]-crystals and their transition to [alpha]-crystals upon tensile testing. Different morphology was observed for the recycled polypropylene (rPP), in which crystallization was affected by polyethylene (PE) contamination. The results discuss the injection molding polymer, structure, and properties, relationship providing an approach to understanding and optimizing the mechanical properties of rPP. Highlights * Polyethylene contamination in polypropylene significantly influences crystallinity. * Recycling contamination reduces the polypropylene's ability to form (3 crystals. * Virgin polypropylene mechanical properties can be tailored through processing conditions. * Recycled polypropylene mechanical properties suffer at higher temperatures and residence times. * Polypropylene [alpha]/[beta] morphologies can be visualized after mechanical testing. KEYWORDS crystallization, hot runner injection molding, recycled polypropylene, 1 | INTRODUCTION Injection molding's ability to mass produce complex parts cost-effectively allowed plastics to become one of the most widely used materials, with injection molding contributing 33% of all [...]

This study aims to predict the compression behavior of ultra-high molecular weight polyethylene (UHMWPE) at various temperatures (25, 40, and 55[degrees]C) and strain rates (~[10.sup.-4]/s and ~[10.sup.-2]/s) using a single set of three-network (TN) viscoplastic model parameters. The TN model is made up of three parallel networks: networks A and B use nonlinear springs and dashpots to control the responses of the crystalline phase and confined amorphous phases, respectively, while network C captures the macromolecular amorphous networks using a single nonlinear spring. A single set of TN model parameters captures the yield and post-yield hardening responses of the stress-strain curves at experimental temperatures and strain rates. When these TN model calibrated parameters are used as material property in a commercial finite element tool to simulate UHMWPE compression, the predicted and simulated results match well, showing the model's fidelity. Additionally, the model predicts experiments conducted at 40 and 70[degrees]C with loading rates of ~[10.sup.-3]/s and ~[10.sup.-2]/s, respectively. The study also correlates the deformations of UHMWPE's crystalline structure and macromolecular amorphous networks with its global stress versus strain response by extracting stresses from individual networks of the TN model at different strain rates and temperatures. Highlights * UHMWPE's mechanical behavior predicted by a single set of TN model parameters * TN model predicts mechanical response at various strain rates and temperatures. * TN model explains microstructural crystalline and amorphous phase deformations. KEYWORDS compression properties, numerical simulations, three-network (TN) viscoplastic model, UHMWPE, 1 | INTRODUCTION Ultra-high molecular weight polyethylene (UHMWPE) is one such polymer, which demonstrates an encouraging potential as an impact, chemical, and wear-resistant material. (1) UHMWPE has found diverse applications, [...]

Polyester-urea coatings were synthesized from corn oil with the help of a series of reactions in three different compositions by varying the amount of urea. Out of all the synthesized compositions, the best composition was optimized based on various parameters. The optimized composition was used as a matrix and graphene oxide (GO) was incorporated in three ratios, for the formulation of corn oil-based CPEUr@GO nanocomposites. Fourier transform infrared spectroscopy was used to confirm all the reactions. The physico-mechanical properties of CPEU[r.sub.2] coating were found to be the best among all the compositions. Therefore, CPEU[r.sub.2] was selected as a matrix for the inclusion of GO nanosheets to prepare CPEU[r.sub.2]@GO nanocomposites. Thermogravimetric analysis results showed that incorporation of GO enhanced the thermal stability of CPEU[r.sub.2] up to 325[degrees] C. The anticorrosive studies revealed the high impedance value of 6.5 * [10.sup.5] [ohm].[cm.sup.2] in case of CPEU[r.sub.2]@G[O.sub.0.5]. Furthermore, it can be concluded that the inclusion of 0.5 wt% GO proved to be the optimized amount to produce sustainable CPEU[r.sub.2] coatings with good performance. These CPEUr@GO nanocomposite coatings can be used for various protective purposes owing to their excellent physico-mechanical thermal as well as anticorrosive performance. Highlights * Corn oil-based polyester-urea, CPEUr, coatings were synthesized in three different compositions. * The best composition was used as a matrix for the formulation of CPEUr@GO nanocomposites. * Graphene oxide of 0.5 wt% was found to be the optimum quantity required to modify CPEUr matrix. * Thermal stability, mechanical durability as well as corrosion resistance performances were enhanced. * The environment friendly approach is suitable for the development of corrosion protective coatings. KEYWORDS corn oil, graphene oxide, nanocomposites, polyurea, 1 | INTRODUCTION Polyurea (PUr) coating represents a recent advancement in the field of coating technology, within the realm of urethane coatings chemistry. (1) PUr coatings exhibit notable mechanical strength [...]

This study numerically investigates the characteristics of a non-Newtonian magnetohydrodynamic flow in a cross-slot. Numerical simulations are performed using power law, Bird-Carreau and Casson non-Newtonian fluid models. The flow characteristics and shear viscosity behavior in the flow region are analyzed for different values of magnetic field. Additionally, the dynamic behavior of the bifurcated flow in the cross-slot is studied in detail, and the computational results are compared with existing models. It is shown that the fluid velocity is reduced in both the inlet and outlet channels of the cross-slot due to the magnetic field, regardless of the viscosity model. Moreover, it is found that the fluid viscosity increases along the centerline of the inlet channels and decreases in the outlet channels of the cross-slot for all non-Newtonian fluid models tested here. Furthermore, this study shows that the flow properties of the non-Newtonian fluids can be controlled by changing the magnetic field strength. The results of this study will be useful for analyzing the flow behavior of blood in a microfluidic cross-slot and other rheological fluids used in biochemical engineering and industrial processes, where higher mass transfer and mixing efficiency can be achieved by imposing an external magnetic field. Highlights * Simulation of non-Newtonian magnetohydrodynamic flow in a cross-slot is conducted. * Analysis of the flow and shear viscosity behavior for different Hartman number is performed. * Flow properties were successfully controlled with the imposed external magnetic field. KEYWORDS cross-slot, magneto-hydrodynamics, non-Newtonian fluids, numerical simulation, 1 | INTRODUCTION Flows in bifurcations (such as T-devices or the cross-slot) occur frequently and are found in a variety of applications, including biochemistry, drug delivery, medical diagnostics, chemical synthesis, [...]

Hot embossing is a low-cost and flexible method for fabricating microstructures and nanostructures on polymers. However, the conventional hot embossing process poses two challenges: First, the plates that are used do not provide uniform pressure, and the size of the chamber limits the imprinting area. Second, heating with thick metal plates significantly lengthens cycle time. Finally, the uniformity of temperature also affects the embossing results. To achieve a high heating rate and uniform pressure over a large area, this study combined an induction heating system and roll-to-plate hot embossing. A movable plate was used to move the mold through the induction coil, increasing the heating area and overcoming limitations related to the embossing area posed by the coil length. The imprinting area reached 100 * 100 [mm.sup.2]. In addition, the temperature difference was less than 20[degrees] C at each molding temperature range from 150[degrees] C to 190[degrees] C. The mold and the substrate were placed on a vacuum absorber to prevent deformation and slippage of the mold and provide preloading and packing pressure. Cooling fans were employed to improve cooling efficiency. Experimental replication yielded replication rates higher than 97% at 190[degrees] C and 5 kgf/[cm.sup.2] with a cycle time of approximately 2 minutes. To verify the feasibility of the process, V-groove microstructures were successfully fabricated using a movable induction heating roller embossing facility. Highlights * The feasibility of the moving induction heating roller embossing process. * A vacuum movable platform prevents deformation and slippage of the substrate. * Improve the temperature uniformity of the movable platform. KEYWORDS hot embossing, induction heating, large area, microstructures, roll-to-plate, 1 | INTRODUCTION Advances in technology, such as the introduction of semiconductors and fiber optic communications, have accelerated the trend toward miniaturization, densification, and high precision in the development of [...]

Slot die coating is a common method of manufacturing electrodes for lithium-ion batteries. In this paper, a multi-objective optimization research on the geometry of dual-cavity die is investigated based on the numerical simulation of lithium battery anode slurry flow combined with the surface response optimization method. First, we use the Plackett-Burman test method to screen the geometric parameters significantly affecting the optimization objective. Then, based on the Box-Behnken response surface analysis method, we determine the optimal combination of parameters. The results show that the inner cavity radius and slot gap are the main structural variables affecting exit-velocity uniformity and die deformation. The slot gap and slot length mainly affect the inlet pressure. The coefficient of deviation of exit velocity uniformity and average inlet pressure of the optimized die structure decreased by 51.3% and 7.6%, respectively. This research provides theoretical guidance for the design of slot coating dies. Highlights * Screening significant geometric parameters using Plackett-Burman test methodology. * Box-Behnken response surface analysis to determine optimal parameters. * Velocity uniformity and inlet pressure increased by 51.3% and 7.6%, respectively. KEYWORDS analysis of variance, Box-Behnken method, dual-cavity die, Plackett-Burman test, structure optimization, 1 | INTRODUCTION Slot die coating technology is the most commonly used manufacturing method for lithium-ion battery electrodes. The lithium-ion battery slurry is transferred to the moving copper or aluminum [...]

Porous polyethylene glycol terephthalate (PET) film is a kind of mesopore structure template with pore size ranging from nanometer to micrometer by chemical etching after irradiation of heavy ions. The etching rate is an important factor affecting the pore morphology and quality of the membrane. In this paper, four stacked PET film were irradiated with 140 MeV [sup.32]S ions at room temperature and vacuum. During chemical etching of irradiated samples, the path etching rate [V.sub.t] was determined by conduction method, and the bulk etching rate [V.sub.b] was determined by weighing method. The relationship between etching temperature, concentration, sensitization time, and etching rate was studied. The results show that the etching rate is exponentially correlated with the etching temperature, and increases linearly with the increase of the etching solution concentration. When the concentration of NaOH is 3 mol [L.sup.-1] and the etching temperature is 75[degrees]C, the formation of cylindrical micropores is the most favorable. The pore size of porous PET film can be adjusted, and the relationship between pore size and etching time is d(nm) = 15nm + 0.24t. This is of great significance for the preparation of nanowires with uniform size and stable properties. Highlights * We have obtained the optimal conditions for obtaining cylindrical holes. * The relationship between the diameter of holes and etching time were determined. KEYWORDS bulk etching rate, heavy ions, mesopore, path etching rate, porous PET film, 1 | INTRODUCTION Template method is one of the most effective methods for the preparation of one-dimensional nanomaterials, which has been recognized and adopted by more and more researchers due [...]

Cleanup of oil spills has become one of the most challenging tasks in recent years, as marine oil spills have had a great negative impact on human health and the ecological environment. This also urgently requires the development of new materials and methods with superhydrophobic properties for oil-water separation. As new porous materials, metal-organic frameworks (MOFs) have attracted much attention due to their unique structures and fascinating properties. However, powdered MOF materials are difficult to recycle, and therefore, suitable substrates need to be selected to construct superhydrophobic composites. The surface hydroxyl groups of cellulose fibers offer great possibilities for their superhydrophobic preparation. In this paper, HDTMS-UiO-66@CFs composites with superhydrophobicity were strategically synthesized by in-situ growth of Zr(IV)-based MOFs linked to hexadecyltrimethoxysilane (HDTMS) on cellulosic fibers (cotton fabric) by using a hydrothermal synthesis method. The HDTMS-UiO-66@CFs composites have a water contact angle of 172[degrees] and the absorption capacity of light oil and heavy oil is more than 1100%, and the oilwater separation efficiency is as high as 96%. Due to the in-situ growth of the HDTMS-UiO-66 material on cotton fibers, which makes the material more resistant and stable, the material can still maintain its superhydrophobic properties in various harsh environments and after repeated use. Therefore, the newly developed HDTMS-UiO-66@CFs composites have a high potential as novel adsorbent materials for cleaning up offshore oil spills and other applications. Highlights * In-situ growth of superhydrophobic metal-organic frameworks (MOF) particles on cellulose fibers. * The porous structure of hexadecyltrimethoxysilane (HDTMS)-Ui066 plays a key role in hydrophobicity. * HDTMS-Ui066@CFs are chemically stable and have long-term durability. KEYWORDS cotton fabrics, hydrophobicity, oil-water separation, zirconium-based metal-organic framework, 1 | INTRODUCTION Marine oil pollution is immensely harmful. Its damage to biodiversity, aquatic ecosystems, coastal and marine ecosystems is serious and ongoing. (1) At the same time, oil pollution [...]

The demolding process in micro-injection molding constitutes a critical phase, exerting a decisive influence on the quality of polymer microstructures. In this study, the demolding forces of PMMA microfluidic chips were measured under different demolding temperatures, packing pressures, and demolding speeds by using pure nickel (Ni) mold insert. The dimensional deviations of the microchannels with different aspect ratios were analyzed. In addition, the effect of mold insert modification on the demolding force was further analyzed. The results showed that the effect of demolding temperature on the demolding force was the most significant, and the peak demolding force decreased with the decrease in temperature. The width of the microchannels increased and the depth decreased after demolding, while the opposite results were observed for the micro-mixing structures. However, the dimensional deviation of the micromixing structures was larger than that of the microchannels. Using the optimal molding parameters, the peak demolding force could be reduced from 114.0 N at 110[degrees]C to 47.0 N, a decrease of 58.8%. It is noteworthy that, when the microchannel was narrower than 100 [micro]m, achieving precise replication of microchannel dimensions became progressively more challenging as the microchannel width decreased. Using the Ni-W[S.sub.2] mold insert with low surface energy and low friction coefficient, the demolding force could be further reduced by 38.3%. The effect of the molding quality of microfluidic chip microstructures on the mixing performance of heavy metals was demonstrated by micro-mixing experiments. Highlights * Demolding temperature crucially affects microstructure dimensions. * Optimal parameters and modified mold insert reduce demolding force by 38.3%. * Dimensional deviation increases with the increase of microchannel aspect ratio. * Optimized microfluidic chip enhances [Co.sup.2+] chemiluminescence by 6.42%. KEYWORDS demolding force, dimensional deviation, microfluidic chip, micro-injection molding, microstructure, 1 | INTRODUCTION Microfluidics is extensively employed in various fields such as biotechnology, chemical analysis, and medical diagnosis. (1,2) Microfluidic chips, which integrate an array of microstructures including microchannels, microcolumns, [...]

To develop a green nanomaterial for specialty applications, spherical nanocellulose (SNC) was functionalized to a semicarbazone-Schiff base via a polymer analogous reaction. Firstly, SNC was synthesized from cellulose extracted from huge forest biomass, pine needles (PNs). The glucopyranose ring of SNC was oxidatively cleaved at C2-C3 to form SNC-dialdehyde (SNC-DA) by periodate oxidation. Both the aldehydic groups generated were reacted with semicarbazide to form a semicarbazone-Schiff base, referred to as functional spherical nanocellulose (FSNC). All the materials synthesized were characterized by FTIR, FESEM, EDS, TEM, and XRD studies. The FSNC was evaluated as an adsorbent for [Hg.sup.2+] ions. The adsorption adhered to pseudo-second order kinetics and Langmuir adsorption isotherm having a maximum adsorption capacity/Lungmuir adsorption capacity of 172.412 mg/g at 60 min. The selectivity of FSNC for [Hg.sup.2+] ions was confirmed from its appreciable removal (82%) from solution in tap water and 70% with other metal ions. FSNC exhibited bifunctional nature as it possesses antimicrobial activity against bacteria, that is, Gram (+) (Bacillus aereus) and Gram (--) (Escherichia coll and Salmonella typhi), and a fungus Byssochlamys fiilva. FSNC showed good recyclability up to eight sorption-desorption cycles. Thus, we have valorized biomass into an eco-friendly and low-cost bifunctional material as an adsorbent for [Hg.sup.2+] ions cum antimicrobial agent. Highlights * Spherical nanocellulose (SNC) prepared via acidic hydrolysis from pine needles * SNC functionalized to semicarbazone-based bifunctional Schiff base * The Schiff base is a rapid and efficient [Hg.sup.2+] ions adsorbent * The Schiff base has good antimicrobial activities against Gram (-) bacteria * Biowaste-based adsorbent has the potential to sustain the bio-circular economy KEYWORDS antimicrobial, pine needles, Schiff base, semicarbazone, spherical nanocellulose, 1 | INTRODUCTION The sustainability development goals have a deep link with the failing water quality and low availability of drinkable water across the world. (1) Among different pollutants, dyes [...]

Foam sandwich composite (FSC) has recently been widely used in transportation, aerospace, shipping, and construction because of its lightweight, high specific strength, stiffness, and fatigue resistance characteristics. This study aimed to prepare, characterize, and test FSC with different diluent addition amounts. Benzyl glycidyl ester was added to the epoxy foam (EF) as a reactive diluent. Then, the EF was introduced into the three-dimensional hollow composite (3DHC) by vacuum introduction process to prepare the FSC. Fourier transform infrared spectroscopy and thermogravimetric analysis demonstrated that increased diluent content enhanced Si--N bond formation, augmenting thermal stability in resin molecules. The effects of different diluents on the mechanical properties of FSC showed that the mechanical properties of FSC were the best when the diluent content was 5 wt%. Compared with 3DHC, the flat compressive strength, flat tensile strength, and shear strength were increased by 7.2, 6.4, and 2.9 times, respectively. Highlights * Diluent improves foaming agent dispersion by lowering resin viscosity. * Diluent makes the EP easier to be introduced into 3DHC. * FSC demonstrates a 723% increase in flat compression strength. KEYWORDS diluent, epoxy foam, fracture, mechanical properties, sandwich composites, 1 | INTRODUCTION Foam sandwich composite (FSC) materials, due to their excellent characteristics of lightweight, high specific strength, high specific stiffness, and fatigue resistance, are widely used in fields such [...]

A silicone rubber foam is prepared by introducing polydiborosiloxane (PDBS) into silicone rubber, and using expandable microspheres as blowing agents. The influences of the dual network structure with dynamic cross-linking network on the silicone rubber foam is characterized by the cell size, mechanical properties and impact resistance. The cell size increases from 77 to 93 [micro]m due to the introduction of a dynamic cross-linking network which reduces foaming resistance. The elongation at break elevates from 277% to 574%, and the yield strength gradually decreases. The dynamic cross-linking network also enhances the internal damping characteristic and energy absorption capacity of the foam. The impact resistance of silicone rubber foam is improved because of the synergistic effect of the dual network structure and the bubble structure. The research improves the performance of silicone rubber foam. KEYWORDS anti-impact, dynamic cross-linking, polydiborosiloxane, silicone rubber Highlights * The dual network structure to improve the mechanical properties. * Excellent cell is obtained using expandable microspheres as foaming agent. * The toughness and elongation are enhanced by regulating the molecular structure. * The dual network structure ameliorates the damping and energy absorption. * Dynamic cross-link and expandable microspheres increase the impact resistance., 1 | INTRODUCTION Silicone rubber as a polymer elastomer is extensively used in various field due to its excellent thermal stability, (1) mechanical property, (2) biocompatibility, and radiation resisting property. [...]

In this paper, a series of novel trans-1, 4-polyisoprene/isotactic polybutene (TPI/iPB) in-reactor blends were synthesized by isoprene and butene sequential two-stage polymerization technology with spherical Ti[Cl.sub.4]/Mg[Cl.sub.2] type Ziegler-Natta catalyst. The components, structures, and properties of the asobtained TPI/iPB reactor blends were characterized by gel permeation chromatography, Fourier transform Infrared spectroscopy, and differential scanning calorimetry. The active trans-1, 4-polyisoprene (TPI) particles obtained in the initial isoprene polymerization by the Z-N catalyst can be acted as microreactors to initiate butene polymerization subsequently. The TPI/iPB reactor blends with varied components were in situ synthesized within the reactor. The preparative-temperature rising elution fractionation (p-TREF) technique was used to fractionate the TPI/iPB reactor blends based on the elution temperature ranged from -40[degrees]C to 90[degrees]C. The weight distribution and microstructure of each fraction were investigated. The reactor blends are composed of crystallizable high trans-1, 4-uint polyisoprene obtained from the first-stage isoprene polymerization, high isotactic polybutene obtained from the secondstage butene polymerization and TPI-b-iPB block copolymer with different sequence structure obtained from the initial time of the second stage. This work is expected to propose the possible polymerizations of a-olefins and conjugated dienes by using heterogeneous Ziegler-Natta catalyst and provide a kind of novel rubber/plastic reactor blend materials. Highlights * The first synthesis of the trans-1,4-polyisoprene/isotactic polybutene reactor blends. * p-TREF technique was used to analyze the composition of TPI/iPB reactor blends. * Detailed structure characterization of the fractions including GPC and NMR * TPI-b-iPB block copolymer can be obtained through the sequential polymerization. * Rubber/plastic reactor blend materials were fabricated by the Z-N catalyst. KEYWORDS 4-polyisoprene, in-reactor blends, polybutene, temperature rising elution fractionation, trans-1, Ziegler-Natta catalyst, 1 | INTRODUCTION The discovery of Ziegler-Natta catalysts has been one of the greatest developments in the synthesis of stereospecific polymers in both academy and modern industry. (1-4) The first [...]

An efficient and scalable method to prepare oligolactic acid stereocomplex microplates (SC-OLA-MPs) is developed. Oligolactic acid was firstly synthesized via the melt polycondensation of lactic acid. Then, the oligo ([sub.L]-lactic acid) and oligo (D-lactic acid) were crystallized with a mixture of dichloromethane and acetone, and consequently the stereocomplex microparticles were obtained in the form of circular microplates with a diameter of approximately 2 [micro]m. As an ecofriendly nucleating agent, SC-OLA-MPs were introduced into poly ([sub.L]-lactic acid) (PLLA) via melt blending. The nonisothermal and isothermal crystallization of the SC-OLA-MPs/PLLA composites were investigated, and the crystal morphology and heterogeneous nucleation phenomena during the isothermal crystallization process were photographed with POM. SC-OLA-MPs show excellent nucleating effects on PLLA crystallization. With the incorporation of 10% SC-OLA-MPs, the crystallization half-time of the SC-OLA-MPs/PLLA composite decreased from 7.18 to 0.45 min at 100[degrees] C, compared to the neat PLLA. Through a short-time molding procedure, the thermal deformation temperature of PLLA is improved by the addition of SC-OLA-MPs. Highlights * Polylactic acid stereocomplex microplates were fabricated by solution crystallization. * This method is easy and scalable. * This microplate is an effective nucleating agent for PLLA. KEYWORDS crystallization, heat resistance temperature, microplates, nucleating agent, poly (Llactic acid), 1 | INTRODUCTION Poly (lactic acid) (PLLA) is a thermoplastic polyester with good mechanical properties, biocompatibility, and transparency, (1-3) which is used in biodegradable materials and composite matrix materials through [...]

Sortation is a crucial step in the mechanical recycling of post-consumer plastics (PCR) whereby properties such as density or spectral signature are used to separate plastics. However, it is difficult to sort polyolefin flakes at high throughput by these properties. We ask whether the frictional properties of plastics as a function of temperature may be used as an alternate sorting property. However, fundamental studies of friction at temperatures near their melting points are limited. Here we measure the temperature dependence of kinetic friction for three common polyolefins (high and low-density polyethylene and polypropylene) as well as polyethylene terephthalate (PET), focusing on the softening/melting regime. The results are augmented by differential scanning calorimetry and temperature-dependence measurements of both dynamic modulus and probe tack. For the polyolefins, we find strong increases in the coefficients of kinetic friction during temperature ramps in the melting/ softening regime. For the PET, we report a notable peak in the kinetic friction which we associate with the glass transition and cold-crystallization. We discuss the enhanced friction in the context of rubber friction, which exhibits comparable coefficients of kinetic frictions. Highlights * Significant upturn in kinetic friction coefficient of polyolefins near melting point * Strong peak in kinetic friction coefficient of polyethylene terephthalate (PET) above glass transition * Correlation of upturns with thermal and mechanical properties and tack * High friction state is analogous to rubber friction * High friction state is a possible mechanism for plastics sortation. KEYWORDS friction, polyolefins, recycling, sorting, thermoplastics, 1 | INTRODUCTION The international efforts to increase plastics recycling rates are driven by the need to reduce plastic pollution, to keep valuable materials within the working economy, and to [...]

In this paper, sulfonic acid functionalized benzothiazole ionic liquid ([[(C[H.sub.2]).sub.3]S[O.sub.3]HBth] [[H.sub.2]P[O.sub.4]]) and graphene oxide were combined together through the cation-[pi]. The sulfonated poly (ether ether ketone) was doped with ionic liquid-modified GO (IL-GO) to prepare the SPEEK/IL-GO composite membrane through the solution casting method. The - S[O.sub.3]H and benzothiazole rings act as both proton acceptors and proton donors during proton transport and can replace the role of water in medium- and high-temperature environments, increasing the proton transport sites to a certain extent and increasing the proton conductivity of the SPEEK/IL-GO composite membrane. The proton conductivity of the SPEEK/IL-GO-2 composite membrane achieved an 18.02 mS/cm at 120[degrees]C, which is 2.43 times higher than that of the pristine SPEEK membrane. This paper provided a method for increasing proton conductivity and limiting IL loss of the SPEEK membrane. Highlights * [[(C[H.sub.2]).sub.3]S[O.sub.3]HBth][[H.sub.2]P[O.sub.4]] and graphene oxide were combined through cation-[pi]. * The benzothiazole ring and -S[O.sub.3]H form acid-base pairs. * The proton conductivity of SPEEK/IL-GO-2 membrane achieved 18.02 mS/cm. KEYWORDS cation-[pi], graphene oxide, high proton conductivity, proton exchange membranes, 1 | INTRODUCTION The massive use of traditional fossil energy sources has caused problems such as environmental pollution and resource shortages. (1-3) New energy technologies are constantly being explored in [...]

To address the escalating issue of oily wastewater, separation membranes with special wettability on the surface are widely used in oil-water separation. The development of separation membranes with not only stable separation flux but also anti-fouling properties is an urgent problem. Therefore, polystyrene/ polyacrylonitrile-polyvinylidene fluoride/polydimethylsiloxane-titanium dioxide nanoparticle (PS/PAN-PVDF/PDMS@Ti[O.sub.2]) composite membranes with superhydrophobicity and lipophilicity were prepared by electrospinning technique. By changing the doping amount of Ti[O.sub.2] nanoparticles, the multilevel rough structure was constructed on the surface, and the transformation of the Ti-O-C chemical bond to the Si-O-Ti chemical bond was realized inside the composite membrane. The results showed that the composite membrane had excellent superhydrophobicity (154.9[degrees]) and mechanical properties (tensile strength of 3.54 MPa, elongation of 60.95%). The membrane can absorb ultraviolet light and exhibits enhanced resistance to fouling when exposed to visibleUV light. Additionally, the composite membrane demonstrates an adsorption capacity of 30-100 g/g for a wide range of oils. In corrosive environments, the composite membrane maintains superhydrophobicity (above 150[degrees]) and achieves high oil-water separation efficiency (97%). After 40 cycles, the separation flux of 6000 L.[h.sup.-1] [m.sup.-2] can be maintained. Hence, superhydrophobic oleophilic composite membranes with a stable separation flux and resistance to fouling can be employed in the field of oil-water separation. Highlights * PS/PAN-PVDF/PDMS@Ti[O.sub.2] composite membrane with multilevel rough structure. * PS/PAN-PVDF/PDMS@Ti[O.sub.2] composite membrane with excellent UV absorption and self-cleaning ability. * PS/PAN-PVDF/PDMS@Ti[O.sub.2] composite membrane with stable oil-water separation efficiency in harsh environments. KEYWORDS electrospinning, membrane, oil-water separation, superhydrophobic, 1 | INTRODUCTION The advancement of science and technology and the rapid growth of industries result in the generation of substantial volumes of oily wastewater across various sectors, including catering, [...]

There are several enviable attributes of titanium and its alloys that contribute to their popularity in biomedical devices and equipment, including their rather low modulus, excellent corrosion resistance, and biocompatibility, good machinability, formability, and strength comprehensive impact and fatigue. Nevertheless, titanium and its alloys do not meet all medical requirements due to its unique properties and alloys, so surface modifications must be made to enhance mechanical, chemical, and biological characteristics. As a review of biomedical engineering, this article discusses specific polymers for coating applications as well as various polymer coatings for functionalization improvements. The versatility of biopolymer coatings makes them extremely appropriate for a broad range of biological uses. To enhance the engineering of tissue and drug delivery, this study summarized and analyzed the most recent advances in biopolymer coatings. Surface qualities of polymer coatings can be adjusted to meet specific criteria for various biomedical applications or integrated with new capabilities. Moreover, polymer coatings containing different inorganic ions can enhance the growth of tissue, proliferation of cells, healing, as well as the transfer of biomolecules, like active molecules, agents of antimicrobial, factors of growth, and medications. Highlights * Surface modification avenues of Ti materials as orthopedic replacements are critically reviewed. * Basic descriptions of titanium and titanium alloys are presented. * Advances in the corrosion behavior of biomedical titanium alloys are thoroughly scrutinized. * Fundamental methods based on mechanical, physical, and chemical princi ples for biopolymer coatings are particularly presented. * Main biopolymer coatings types that are used on titanium surfaces are reviewed. KEYWORDS biomedical applications, biopoiymer, coating, corrosion resistance, titanium alloys, 1 | INTRODUCTION The concept of replacing lost limbs and organs in the human body was present in many ancient civilizations, not only to honor the dead but to honor [...]

Poly(butylene adipate-co-terephthalate) (PBAT) is one of the solutions to the energy crisis and white pollution. However, the poor thermo-oxidative stability limits its wide applications. In this work, Chrysanthemum morifolium extract (CME) as a natural additive was used to modify the PBAT. The oxidation onset temperature (OOT) results showed that the CME could provide PBAT with high thermal oxidation stability. By the presence of 2.5 wt% CME, the OOT value of PBAT-[CME.sub.2.5] increased by 52[degrees] C compared with the neat PBAT. The outstanding antioxidant capacity is attributed to the excellent free radical quenching capacity of CME, whose main components consist of six kinds of phenolic compounds. Moreover, the PBAT-[CME.sub.1.5] composite could achieve the balance between the mechanical property and thermo-oxidative stability, the OOT result of PBAT-[CME.sub.1.5] increased by 42[degrees]C, the tensile strength reached 103.1%, and the elongation at break could retain 91.4% of that of neat PBAT. Besides, the processing property, degradation performance, and surface hydrophobic nature of modified PBAT samples were all improved. This work proposes a facile method to obtain completely natural biodegradable composites to expand the practical applications of PBAT. Highlights * The main components in CME are phenolic compounds. * CME showed high free radical scavenging efficiency. * CME improved the thermal oxidation stability of the PBAT matrix. * The addition of CME could still maintain good mechanical properties of PBAT. * The introduction of CME promoted the degradation of PBAT films. KEYWORDS antioxidants, biodegradable, thermal properties, 1 | INTRODUCTION The accumulation of plastic waste has brought about increasing environmental pollution, which is mainly due to the massive use of nonbiodegradable, fossil fuel-based polymers, whose degradation time [...]

In the mobility market, there is a demand from customers for antimicrobial protection. As a result, the market has grown considerably to provide antiviral and antimicrobial polymers and coatings. This study examines how the efficacy of a non-commercial antimicrobial thermoplastic elastomer will change over the life of the application. Using an example application of an electric scooter handlebar grip, durability requirements were identified, and antiviral efficacy (exceeding a log value of 3 or >99.9 microbial growth reduction) was compared before and after testing. A scooter handlebar grip was selected as the ideal example application as it was a high-touch surface, with several different riders. During the start of this study, scooter companies were encouraging their riders to disinfect scooter handlebars before riding, use hand sanitizer, and wear gloves. If the handlebar grip could be antimicrobial, then they could eliminate these steps and provide a safe ride for the users. In order to simulate long-term durability, UV exposure, temperature, humidity, artificial sweat, sunscreen, insect repellent, and abrasion tests were performed and evaluated in terms of antiviral activity. Accelerated weathering reduced the virucidal activity of the sample versus unexposed antiviral thermoplastic elastomer (TPE). However, the efficacy increased with contact time from 90% to 96.83% at 30 and 120 min, respectively. Abrasion resistance of antiviral TPE showed a volume loss of 66 [mm.sup.3] compared to control samples of 83 [mm.sup.3]. The antiviral TPE sample exhibited slightly lower efficacy compared to the control after exposure to the artificial sweat (99.43% vs. 99.95%). Additionally, a skin tolerance test conducted on rabbits showed that antiviral TPE was not an irritant and showed no dermal toxicity. The outcome of this study will lead to the development of long-term durable antimicrobial material for the transportation industry. Highlights * The effectiveness of an antimicrobial material depends on various environmental factors. * Accelerated weathering of the antiviral TPE reduced the efficacy. * The antiviral TPE was non-irritating to the skin. * Significant research needs to continue in this area to provide safe and robust solutions. * This approach to antimicrobial incorporation can now be applied to the transportation industry. KEYWORDS aging, antiviral additives, thermoplastic elastomers, thermoplastics, 1 | INTRODUCTION The COVTD-19 pandemic has altered people's driving and travel habits and has dramatically increased the demand for cleanliness of a vehicle. Studies have shown that whether it [...]

Collagen (Col)-based composite hydrogels have attracted wide attention because of the additional properties that the second component brings to the hydrogel. Here we reported self-assembly of collagen and cross-linking of alginate with [Ca.sup.2+] to prepare a novel composite hydrogel with Tilapiaskin-derived collagen and alginate for efficient wound repairing as the wound dressing. The composite hydrogels exhibited higher water content, coupled with a significant increase in water retention rates upon the incorporation of alginate. As the concentration of alginate rose, the cross-linking network became tighter, thereby not only modifying the internal structure of the hydrogel but also enhancing its mechanical strength. Moreover, the collagen degradation rate in the composite hydrogels was greatly reduced through addition of alginate, and the collagen-alginate composite hydrogels exhibited low cytotoxicity, and improved wound healing efficacy, accelerating the maturation of skin attachments and the secretion of vascular endothelial growth factor (VEGF). These results suggested that the composite hydrogel formed by fish-derived collagen and alginate held promising potential as a wound dressing for challenging and refractory wounds. KEYWORDS alginate, characterization, collagen, composite hydrogel, wound dressing Highlights * Tilapia-skin-derived collagen/alginate hydrogels was prepared by selfassembly and cross-linking method. * The introduction of alginate improves the mechanical strength of collagen hydrogel. * The addition of alginate can slow down the degradation of collagen. * The composite hydrogels retain high water content and low cytotoxicity. * The composite hydrogels can promote wound healing significantly., 1 | INTRODUCTION Refractory wounds, such as severe frostbite, burns and ulcers, can cause full-thickness skin damage and are difficult to repair, (1,2) which brings great pain to patients, and [...]

In this study, a wound-healing membrane was fabricated based on carboxymethyl cellulose (CMC) and polyethylene glycol (PEG) containing curcumin (Cur) and bromelain (Br). Citric acid (CA) was used as a cross-linking agent. This membrane showed an ideal degree of swelling, which was significantly dependent on the concentration and duration of cross-linked CA. The chemical characterization showed the CA cross-linker mechanism was more associated with chemical reactions with CMC carboxyl groups, and PEG hydroxyl groups played an important role in forming a hybrid polymer network. It greatly enhanced mechanical and adhesive properties, so the stress strength was improved from 29.4 to 38.52 Mpa. The hydrophilicity of the membrane surface according to the water contact angle assay showed the membrane surface is suitable for adhesion, growth, migration, and proliferation of skin cells. The drug delivery assay demonstrated that the Br and Cur were released during 48 h, but the Br followed the burst release in comparison with Cur. Antibacterial properties showed that CMC/PEG-Cur/Br have ideal antibacterial properties for preventing the growth of bacteria. In summary, the engineered CMC/PEG containing Cur/Br films with desired cell viability properties and antibacterial activity can potentially improve and accelerate skin regeneration for chronic wound healing. Highlights * Hydrogel film was prepared based on carboxymethyl cellulose (CMC), polyethylene glycol (PEG), and citric acid as cross-linking agent. * CMC/PEG film were induced controlling curcumin (Cur) and bromelain (Br) release for wound healing process. * CMC/PEG film revealed a wide range of physiochemical, mechanical, adhesion, and biological properties behavior. * Incorporation of Cur and Br promoted in vitro biocompatibility, L-929 cells attachments, and cell migration. KEYWORDS antibacterial properties, bromelain, carboxymethyl cellulose, curcumin, drug delivery, polyethylene glycol, wound dressing, 1 | INTRODUCTION As the largest human tissue, the skin serves a crucial role as a barrier against infection. (1) Due to an incomplete physical barrier and exposed subcutaneous tissue, [...]

A new highly effective sizing reagent based on grafted collagen copolymers has been proposed for cotton yarn. The copolymers were synthesized by reacting an aqueous solution of collagen with acrylic monomers--acrylic, matacrylic acids, and their amides in the presence of potassium persulfate. Based on Scanning electron microscopy--Energy dispersive (SEM-EDS) analysis data, the composition of the copolymers was determined. Unsaturated acids are more actively grafted onto collagen than their amides. When a polymer film is formed from a solution of a collagen copolymer with (meth)acrylic acid, microcracks appear on the surface of the sample; microcracks are absent in films of copolymers with (meth)acrylamide. Films of copolymers, especially methacrylamide, are quite flexible and contribute to a significant improvement in the properties of the yarn. The tensile strength of yarn sized with copolymers increases by 20%-65% compared to unsized yarn, and by 13%--38% compared to yarn sized with a starch solution. At the same time, the relative tensile elongation of the experimental yarn improves by 14%-58%, while this property of starch-size yarn deteriorates by 14%-22% compared to unsized yarn. The complete removal of graft copolymers from the surface of the yarn in the process of biochemical desizing using the enzyme protease is shown. Highlights * Graft copolymerization of (meth)aciylamide with collagen was carried out. * Grafting is initiated by the interaction of collagen with potassium persulfate. * The synthesized copolymers are effective sizing reagents for cotton yarn. * The copolymer with poly(meth)acrylamide forms a flexible and stable film. * The protease enzyme completely removes the size from the surface of the yarn. KEYWORDS acrylic monomer, collagen, cotton yam, graft copolymer, morphology, sizing, 1 | INTRODUCTION The preparation of cotton yarn for weaving is a technological link between the production of yarn and the production of fabric, therefore it plays a significant role [...]

As the primary goal in the wound care intervention is the promotion of rapid wound healing, researchers sought to find a remedy. In this progression course, nanocomposite-based hydrogels have attracted the attention. Herein, we used a polyvinyl alcohol (PVA) hydrogel in combination with two forms of clay nanoparticles, namely unmodified montmorillonite (MONT) and modified (OMONT), to fabricate a nanocomposite-based hydrogels and combat the lack of stem cells' adhesion to PVA, followed by seeding of adipose-derived stem cells (ADSCs) on them. To investigate the characteristics of these constructs, corresponding tests were performed. The Young's modulus and elongation at break of PVA/5% OMONT were 3.7 [+ or -] 0.014 and 800 [+ or -] 35, respectively, which were higher than those of PVA/5% MONT (3 [+ or -] 0.03 and 320 [+ or -] 14). In addition, the hardness of the modified group (7.2 [+ or -] 0.07) was lower than the unmodified one (9.8 [+ or -] 0.07). The water vapor transmission rate (WVTR) in the OMONT group was 39 [+ or -] 0.28, which was lower than PVA/5% MONT (46 [+ or -] 4.24). Hence, ADSCs/PVA montmorillonite dressing may improve wound healing and provide a new way to employ stem cells, significantly impacting skin tissue engineering safely. Highlights * Modified montmorillonite had higher stem cell binding. * The lack of stem cells' adhesion to polyvinyl alcohol (PVA) was solved. * Adipose-derived stem cells/PVA montmorillonite dressing may improve wound healing. * It is a novel promising approach for skin tissue engineering. KEYWORDS montmorillonite, nanocomposites, PVA hydrogel, stem cells, 1 | INTRODUCTION As the primary goal in the wound care intervention is the promotion of rapid wound healing, researchers sought to find a remedy. (1) In this progression course, [...]