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Sodium polyacrylate (PAAS), a macromolecule surfactant, was employed in the synthesis of polyvinyl butyral (PVB) using a deep eutectic solvent (DES) as the catalyst. Contrasting with traditional low molecular weight surfactants, scanning electron microscopy (SEM) analysis has confirmed that PAAS enhanced the uniformity of PVB granules while minimizing PAAS residuals, facilitating the production of films with superior transparency and resistance to yellowing. Investigations into the effects of varying molecular weights, dosages of PAAS, and aging times on the properties of PVB revealed that an increase in PAAS molecular weight correspondingly raised the acetal degree (AD) of PVB without affecting the molecular weight of PVB itself. Furthermore, yhe dosage of PAAS significantly impacted the properties of PVB, whereas aging time exhibits minimal influence on the AD of PVB. 1H‐NMR analysis indicated that the structural stability of PVB is due to the dominance of meso acetal isomers, which improved its mechanical properties when synthesized with PAAS3 (molecular weight 60,000 g/mol), containing 91.5% hexamethylene cycloacetal. Notably, compared to PVB synthesized using sodium dodecyl sulphate (SDS), PVB synthesized with PAAS3 exhibits superior mechanical properties, with significantly improved tensile strength and elongation. This phenomenon is further elucidated by SEM images. A comparison between the optimized self‐made PVB and commercial PVB shows that the self‐made PVB performs better, highlighting the critical role of macromolecular PAAS in enhancing the structure and mechanical properties of PVB. [ABSTRACT FROM AUTHOR]

BACKGROUND: Various types of hydrogel compounds have recently been developed for controlling invasive and pest ants in a range of environmental settings including agricultural, urban and natural areas. The current study evaluated the potential of sodium polyacrylate (ACR) hydrogels to effectively deliver liquid baits to Argentine ants. RESULTS: Relative to standard polyacrylamide (PAM) hydrogels, individual ACR hydrogel particles were approximately five‐fold heavier; this may affect how ants interact with the bait particles, and further influence bait uptake and efficacy. Additionally, ACR hydrogels had significantly higher water absorption capacity and significantly slower rate of water loss, especially during the first 2 h. The efficacy of ACR hydrogel bait containing 0.005% fipronil and various attractants was evaluated on laboratory colonies. Results demonstrated that ACR hydrogel acceptance is significantly increased by the addition of feeding attractants. In addition, a field trial was performed in a nature reserve invaded by Argentine ants to evaluate the efficacy of ACR hydrogel bait. The field trial demonstrated that ACR hydrogel bait containing 0.005% fipronil with various attractants is highly effective and that ant densities throughout the baited plots declined by >99% within 7 days. CONCLUSIONS: The results of this study demonstrate that: (i) fipronil is highly effective for Argentine ant control in natural areas when used in low concentrations (0.005%); (ii) ACR hydrogels are an effective tool for delivering liquid baits to Argentine ants; and (iii) hydrogel baits augmented with various attractants including salt, protein and pheromone are highly attractive to Argentine ants. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Abstract With the advancement of ecological and environmental protection construction, the research on the modification of expansive soil using environmentally friendly polymers can make up for the harm to the ecological environment caused by traditional modification. Mechanical and microscopic properties of modified expansive soils were analyzed through indoor tests. The results showed that the liquid limit and plasticity index decreased by 52.14% and 77.36%, respectively, and the plastic limit increased by 20.83%. Maximum dry density decreased by 5.11% and optimum moisture content increased by 28.47%. The compressive and shear strength increases and then decreases with the increase of dosage, and the strength reaches the maximum when the dosage is 4%, and the vertical and lateral deformation of the specimen is the smallest. Modified soil swelling was reduced by 54.57% and swelling forces were reduced by 15–57%. The modified soil cracks developed slowly and the width of the cracks was reduced by 61.68% after the modification. Microscopy showed that no new minerals were generated after doping modifier, while hydrophilic minerals were reduced by 43.14%, and the gel film formed by hydration made the pores smaller and the structure tighter by filling and wrapping on the surface of the particles.

Abstract Background Super-absorbent polymers (SAPs) possess the ability to absorb large amounts of water and are widely used in medical settings. Commonly used in vomit bags to contain fluids, reduce spillage, and enhance bedside hygiene, SAPs are generally regarded as safe and non-toxic. However, we report a tragic incident where the accidental ingestion of SAPs led to fatal asphyxiation, highlighting a critical safety concern. Case presentation A 76-year-old female suffering from advanced Alzheimer’s dementia was brought to the emergency department following a fall with cervical trauma. Following a complaint of nausea, she was given a vomit bag containing a sachet of approximately 9 g of SAP. Thirty minutes later, she was found deceased in the waiting area, with a grayish, half-hardened gel blocking her oropharynx and remnants of a chewed SAP sachet. Pathological analysis confirmed death by asphyxiation caused by the SAP expanding in her oropharynx upon contact with saliva. Conclusions This case emphasizes the potential dangers of SAPs when accidentally ingested and it is imperative that such products are kept out of reach of vulnerable populations. In cases of airway obstruction, there are no specific treatments available. Laryngoscopy may be impossible, necessitating the prompt consideration of an emergency tracheotomy. Experimental data suggest the use of an aerosol of warm alkaline hydrogen peroxide solution to dissolve these obstructive foreign bodies, but further studies are needed to validate its use in emergency situations.

In general, fine coal with high ash is usually difficult to clean because of kaolin in the flotation pulp. It is necessary to find some effective methods for the high-precision flotation of coal from kaolin. In this investigation, sodium polyacrylate (PAAS) was selected as a selective flocculant and depressant for fine kaolin in coal flotation pulp. Focused beam reflectance measuring instrument (FBRM), particle video microscope (PVM), infrared spectrometer, contact angle measuring instrument and scanning electron microscope (SEM) were used to reveal the interaction between sodium polyacrylate and coal or kaolin. The results show that with the increase in concentration, PAAS could adsorb on the surface of kaolin through hydrogen bonding, which promoted the formation of fine kaolin particles into flocs, and reduced the surface area of kaolin. PAAS had a dispersing effect on coal. PAAS inhibited the flotation behavior of kaolin, and the flotation index was optimal when the dosage of PAAS was 20 mg/L. Adding an appropriate dosage of PAAS into the coal flotation system can form kaolin floccules, which reduced the entrainment of kaolin in clean coal by water flow, thereby improving the flotation selectivity of coal from kaolin. [ABSTRACT FROM AUTHOR]

Chronic obstructive pulmonary disease (COPD) is a common pulmonary disorder with high morbidity, often leading to complications like pulmonary hypertension. Kaempferol, with its antioxidant and anti-inflammatory properties, shows promise in improving COPD outcomes. In this study, we developed a pH-sensitive fluorescent polymer, PAAS-DIA-SDOO, to load 4-(2-methoxyphenyl)-2-methyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylic acid methyl ester and kaempferol, forming the nanocomposite PAAS-DIA-SDOO@1@Kaempferol. This nanocomposite demonstrated high drug-loading capacity and allowed real-time monitoring of drug release. In COPD model cells, it significantly enhanced cell proliferation and reduced inflammation, highlighting its potential as a smart drug delivery system for targeted COPD treatment. This innovation offers promising therapeutic improvements by enhancing drug efficacy and reducing side effects. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study analyzes the behavior of sodium polyacrylate (NaPA) as a rheological modifier for clay-based tailings. Special emphasis is placed on the impact of calcium and magnesium ions in industrial water, which are analyzed through rheograms, zeta potential measurements, and molecular dynamics simulations. The results are interpreted as electrostatic interactions, steric phenomena, and cation solvation. This interpretation integrates experimental studies with microscopic analyses, employing molecular dynamics simulations to elucidate the underlying mechanisms. In all cases, a decrease in the yield stress of synthetic slurries is observed as the dosing of NaPA increases due to greater repulsion between tailings particles through an increase in electrostatic repulsion and larger steric forces that hinder agglomeration. However, efficiency is reduced in the presence of divalent cations as zeta potential measurements suggest a reduction in the electrical charges of the particles and the polymer, making its application more challenging. The differences obtained in the presence of calcium compared to magnesium are explained in terms of the solvation of these ions and their impact on the polymer conformation in solution and adsorption on the mineral surfaces. This explanation is reinforced by molecular dynamics studies, which indicate that polymer adsorption on minerals depends on the type of mineral and type of ion. Particularly for quartz, the highest adsorption of NaPA occurs in the presence of calcium, whereas for a kaolinite surface, the highest polymer adsorption is obtained in the presence of magnesium. The competitive effect of these phenomena leads to the rheological behavior of the tailings being dominated by the effects originating in the clay. [ABSTRACT FROM AUTHOR]

Background: Super-absorbent polymers (SAPs) possess the ability to absorb large amounts of water and are widely used in medical settings. Commonly used in vomit bags to contain fluids, reduce spillage, and enhance bedside hygiene, SAPs are generally regarded as safe and non-toxic. However, we report a tragic incident where the accidental ingestion of SAPs led to fatal asphyxiation, highlighting a critical safety concern. Case presentation: A 76-year-old female suffering from advanced Alzheimer's dementia was brought to the emergency department following a fall with cervical trauma. Following a complaint of nausea, she was given a vomit bag containing a sachet of approximately 9 g of SAP. Thirty minutes later, she was found deceased in the waiting area, with a grayish, half-hardened gel blocking her oropharynx and remnants of a chewed SAP sachet. Pathological analysis confirmed death by asphyxiation caused by the SAP expanding in her oropharynx upon contact with saliva. Conclusions: This case emphasizes the potential dangers of SAPs when accidentally ingested and it is imperative that such products are kept out of reach of vulnerable populations. In cases of airway obstruction, there are no specific treatments available. Laryngoscopy may be impossible, necessitating the prompt consideration of an emergency tracheotomy. Experimental data suggest the use of an aerosol of warm alkaline hydrogen peroxide solution to dissolve these obstructive foreign bodies, but further studies are needed to validate its use in emergency situations. [ABSTRACT FROM AUTHOR]

To study the engineering properties of red clay modified by sodium polyacrylate, the Liuzhou remodeled red clay cured by sodium polyacrylate was selected for the permeability test with variable head and triaxial shear test to analyze the permeability and mechanical properties of the modified red clay and to determine the optimum amount of sodium polyacrylate. The disintegration resistance and microscopic mechanism of the modified red clay were determined by the disintegration test and scanning electron microscope test, respectively. The results show that the permeability coefficient of the modified soil decreases gradually with the increase of sodium polyacrylate, and gradually stabilizes after reaching 3% with the permeability coefficient of 8.1379×10−7 cm/s, 90.78% lower than that of the plain soil. In contrast, the shear strength of the modified red clay shows an increasing trend firstly, then decreases, and then keeps stable at at 2%, which is 394.21% higher than that of the plain soil. The optimal dosage is 3%, and in such situation, the anti-disintegration performance of the modified soil is improved by 42.86%. The pores between the soil particles filled by polymer chains lead to the continuous fragmented granular red clay . The arrangement structure and denseness are better than those of the plain red clay. The impermeability, mechanical properties, and disintegration resistance of the red clay modified by sodium polyacrylate are significantly improved. This study can provide theoretical information for the practical engineering.

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study investigated the interaction of monovalent cations with different sizes on quartz surfaces and the rheological impact that this causes in concentrated suspensions when subjected to the action of a rheological modifier, in this case, sodium polyacrylate (NaPA). Yield stress was determined using a rheometer with a vane-in-cup configuration to establish the relationship between shear stress and strain. Experiments were carried out in LiCl, NaCl, KCl, and CsCl solutions. The results show that the yield stress increases following the order Li < Na < K < Cs in the absence of PAA. However, the addition of NaPA significantly reduced the yield stress in all cases. This reduction was more noticeable in the LiCl and NaCl solutions than in the KCl and CsCl solutions, suggesting a more pronounced effect of PA in maker salts. We conducted molecular dynamics simulations to understand how PA interacts with dissolved salts on the quartz surface. Our results showed that Li had the highest adsorption, followed by Na, K, and Cs. As the salt concentration increased, so did the adsorption. We validated these simulation results with rheological experiments, which helped us understand the observed differences. The molecular interactions indicate that, in the lithium system, cationic bridges and the synergy between hydrogen bridges and hydrophobic bridges predominate mainly. This tendency decreases as the type of cation is changed due to the decrease in the electrical density of the cation in the following order: Li < Na < K < Cs. This reduces bridging with the quartz surface and, therefore, directly impacts the system's rheological properties. [ABSTRACT FROM AUTHOR]

A series of polymeric aqueous biphasic systems (ABS) were determined using polyethylene glycol (PEG) and sodium polyacrylate (NaPA) with choline chloride ([Ch]Cl) as an adjuvant. The effect of (i) PEG and NaPA molecular weights, (ii) PEG functionalization, (iii) [Ch]Cl addition (at different concentrations), and (iv) temperature (25, 37 and 50 °C) was evaluated through their ability to promote the two-phase separation. The results showed that the polymerization degree and functionalization of PEG polymers exhibit a large influence on the ABS formation, with high molecular weight PEG inducing an increase in the biphasic region. Furthermore, the addition of small amount (1–5 wt%) of [Ch]Cl also increased the liquid–liquid demixing. Temperature and the increase in the NaPA molecular weight did not influence the ABS formation ability. Finally, the partition performance of PEG/NaPA + [Ch]Cl ABS was evaluated using caffeine as a model compound. Unlike the ABS formation trend, NaPAs molecular weight significantly influenced the partitioning, which was strengthened when using NaPA-8000. Moreover, the incorporation of [Ch]Cl facilitated an inversion in the partitioning behavior of caffeine, thereby emphasizing the remarkable partitioning tailoring potential exhibited by these systems. Overall, all systems seem to be promising alternatives for the effective extraction, purification and/or concentration of different value-added biomolecules. [ABSTRACT FROM AUTHOR]

Seawater has been desalinated using various processes at different techniques, most of which depend on fossil fuels. On the contrary, there is a need for environmentally benign desalination systems. Adsorption desalination system (ADS) is one of these systems that employ eco-friendly materials to reduce environmental pollution and global warming. This paper examines the performance metrics of promising materials used in ADS to lower desalinated water prices. This research uses sodium polyacrylate (SP), special SP/(NH4)2CO3 activated materials, and SP/CaCl2 composite to theoretically examine ADS's performance and cost analysis. Also, ADS performance with and without heat recovery (HR) is compared. Using tools from MATLAB and TRNSYS, the model is carried out over a year using live weather data from hot regions. Results show that the SP/CaCl2 composite has a relatively high specific daily water production (SDWP) of 15 m3/ton with COP = 0.67. The SDWP can be increased up to 45 m3/ton if heat recovery is used in the system. The cost of desalinated water is estimated at 3.8 $/m3 using Solar energy and 0.63 $/m3 using waste heat evaluated for a system with HR.

Sodium polyacrylate (PAA-Na) was selected as a polymer to modify sodium bentonite (NaB) to improve its chemical compatibility, thereby improving the hydraulic properties of polymer-modified bentonite–sand mixtures (PMBS). In this study, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to clarify the modification mechanism of polymer-modified bentonite (PMB). The free swell index and hydraulic conductivity tests were conducted to determine the effects of ions, pH, non-prehydration, and wet–dry cycles on the hydraulic properties of PMBS and sodium bentonite–sand mixtures (NaBS). SEM–EDS results confirmed that a cluster of bentonite particles, including micropores, were wrapped by a three-dimensional crosslinked network structure of PAA-Na. Compared with the free swell index (FSI) of NaB (35 mL/2 g), the FSI of PMB increased to 86 mL/2 g in deionized water, and the FSI of PMB was found to be 2–3 times higher than that of NaB in all tested solutions. The results of hydraulic conductivity tests showed that with identical compaction levels, PMBS, with hydraulic conductivities of less than 1 × 10−8 cm/s in all permeant liquids, had lower hydraulic conductivities than that of NaBS. In addition, PMBS exhibited excellent self-healing capacity, with almost all the surface cracks being able to heal after nine wet–dry cycles involving tap water, so that PMBS could always maintain a very low hydraulic conductivity of around 5 × 10−9 cm/s. In contrast, the volume of NaBS shrank by 8.15% after nine wet–dry cycles, leading to an increase of four orders of magnitude in its hydraulic conductivity. [ABSTRACT FROM AUTHOR]

Reaktif boyarmaddeler pamuğun boyanmasında en yaygın kullanılan boyarmaddelerdir. Pamuklu kumaşların reaktif boyanması için yüksek miktarda kullanılan elektrolit kaçınılmaz olarak çevresel tehditler oluşturmaktadır. Kitosan üstün özelliklerinden dolayı tekstilde birçok alanda farklı amaçlarla kullanılmaktadır. Bu çalışmada, sentetik polielektrolit poli(akrilik asidin sodyum tuzu) reaktif boyamada inorganik elektrolit sodyum klorür yerine kullanımı ve kitosanın kumaşın reaktif boyama davranışı üzerindeki etkileri araştırılmıştır. Ayrıca kumaşların yıkama haslıkları ve ultraviyole koruma faktörleri de gözlemlenmiştir. Boyamadan önce kitosan ile muamele ve boyamada sodyum klorür kullanımı konvansiyonel boyamalara göre renk derinliklerini arttırmış ve bu artış kitosan konsantrasyonundaki artışla devam etmiştir. Öyle ki, %8 konsantrasyonda kitosan uygulamasını takiben %2 konsantrasyonda yapılan boyamadan, %3 konvansiyonel boyamanın renk kuvvetine benzer değerler elde edilmiştir. Sodyum klorür konsantrasyon artışının renk derinliği üzerindeki etkisi polielektrolitten daha belirgin olarak gözlemlenmiştir. Poli (akrilik asidin sodyum tuzunun) pamuğun reaktif boyamasındaki çalışma prensibinin iyonlaşamaması, sıcaklık-konsantrasyon-pH duyarlılığı ve hidrofobik boya kombinasyonları oluşturması nedeniyle nispeten karmaşık olduğu anlaşılmıştır. Ayrıca boyarmaddelerin farklı tuz duyarlılıklarının da elektrolitlerin etkisinde farklılık yaratmış olabileceği düşünülmüştür. Kitosan aplike edilen ve boyanan numunelerin yıkama haslıkları iyi-mükemmel seviyede iken, kitosan aplikasyonunda kullanılan çapraz bağlayıcının bu değerleri 0,5 puan kadar artırdığı görülmüştür. Boyarmaddelerin ultraviyole koruma faktörünü arttırmada kitosandan daha etkili olduğu gözlemlenmiştir.

Abstract Composites are relevant to high-performance materials in the aerospace sector and have attracted the attention of the scientific and technological communities. Bentonites present very fine granulometry which enables their use in composites. This study showed the development of water absorbent composite based on sodium polyacrylate, bentonite coated by epoxy resin. Since there are gaps in the quantification of composite materials by near-infrared spectroscopy, especially by reflectance analysis (NIRA), this paper shows a quantification methodology (A7200/A5202) of sodium polyacrylate and bentonite. The methodology error found was 1.45% (95% of coefficient of determination). The effectiveness of the developed infrared methodology was verified showing that values are close to the nominal, especially for lower bentonite content. Besides, scanning electron microscopy (SEM) and universal attenuated total reflection (UATR) analysis evidenced the coating with the epoxy resin. Such development ensures rapid and precise methodologies that can be applied to the quality control of composite materials.

ABSTRACT The phenomenon of desertification has a negative impact on the national economy of any country and may usually be obtained for many reasons such as the removal of agricultural land, depletion of soil, overgrazing, methods of poor irrigation, high temperature, and the lack of rainfall. The following paper tackles solving the problem of the lack of rainfall through the use of chemical methods such as preparing sodium polyacrylate and improving its properties by means of adding bentonite and thus obtaining a new and improved water absorption compound. The study concludes that the suitable range of bentonite ratio that is between (0 - 20 wt %) ensures water absorption from 1340 gg - 1 to 1500gg – 1 and thus the researcher confirms that the cross-linked of the compound will not be changed and the absorption of water will be higher. The presence of bentonite with polymer at a perfect percentage contributes to the reorganization of the distribution of the granular size of the polymer sodium polyacrylate—a matter that is reflected on the growing of its ability to absorb water and thus becoming a suitable compound in the treatment of desertification.

With the growing demands of human beings, sanitary landfill, along with the increase in landfill depth and leachate water pressure, has put forward new and higher requirements for the impermeable layer. In particular, it is required to have a certain adsorption capacity of harmful substances from the perspective of environmental protection. Hence, the impermeability of polymer bentonite–sand mixtures (PBTS) at different water pressure and the adsorption properties of polymer bentonite (PBT) on contaminants were investigated through the modification of PBT using betaine compounded with sodium polyacrylate (SPA). It was found that the composite modification of betaine and SPA could reduce the average particle size of PBT dispersed in water (reduced to 106 nm from 201 nm) and enhance the swelling properties. As the content of SPA increased, the hydraulic conductivity of PBTS system decreases and the permeability resistance improves, while the resistance to external water pressure increases. It is proposed a concept of the potential of osmotic pressure in a constrained space to explain the impermeability mechanism of PBTS. The potential of osmotic pressure obtained by linear extrapolation of the trendline of colloidal osmotic pressure versus mass content of PBT could represent the external water pressure that the PBT resist. Additionally, the PBT also has a high adsorption capacity for both organic pollutants and heavy metal ions. The adsorption rate of PBT was up to 99.36% for phenol; up to 99.9% for methylene blue; and 99.89%, 99.9%, and 95.7% for low concentrations of Pb2+, Cd2+, and Hg+, respectively. This work is expected to provide strong technical support for the future development in the field of impermeability and removal of hazardous substances (organic and heavy metals). [ABSTRACT FROM AUTHOR]

The blended composites with ultra-high molecular weight polyethylene (UHMWPE) as the matrix polymer, sodium polyacrylate (PAANa), and tetraphenyltin (Ph4Sn) as fillers were prepared by hot compression molding process. The friction and wear behavior of GCr15 balls with composites mating pairs under the seawater environment was explored, and the friction and wear mechanism was analyzed. The results show that adding PAANa, a polyelectrolyte material, can effectively reduce the friction coefficient of UHMWPE/PAANa/Ph4Sn composites. The wear resistance of composites increased significantly with increasing Ph4Sn content compared with pure UHMWPE, and the best wear resistance was observed at 1% content. The primary wear mechanism of UHMWPE/PAANa/Ph4Sn composites changed from adhesive wear of pure UHMWPE to plastic deformation at lower PAANa and Ph4Sn contents and finally to adhesive wear and spalling. This work provides a theoretical basis for preparing and applying other polymer blend composites. [ABSTRACT FROM AUTHOR]

Landfill leachate, a complex mixture of pollutants, poses a significant environmental hazard. This study reports the synthesis and characterization of superabsorbent nanocomposites (SANs) designed for enhanced performance in waste management applications. SANs were prepared using carboxymethyl cellulose (CMC) and sodium polyacrylate (SPA) as the main components, carbon dots (CDs) to improve absorption, and Satureja Khuzestanica essential oil (SEO) for antibacterial performance. The results demonstrated that the addition of CDs significantly increased the absorption capacity and liquid retention of the samples, with a water absorption capacity reaching up to 8621 %. Furthermore, the samples exhibited high mechanical strength, with tensile strength improving by over 100 % in the presence of CDs. The inclusion of SEO provided strong antibacterial activity against Escherichia coli and Staphylococcus aureus , with inhibition zones measuring up to 26 mm. These SANs, with their high absorption capacity, mechanical robustness, and antibacterial properties, show great potential for improving waste management practices, particularly in leachate absorption strategies. • Developed superabsorbent nanocomposites (SANs) for effective landfill leachate treatment. • Utilized carboxymethyl cellulose and sodium polyacrylate as base materials for SANs. • Enhanced absorption and liquid retention with plant-derived carbon dots. • Improvement of antibacterial properties using Satureja Khuzestanica essential oil. [ABSTRACT FROM AUTHOR]

Aqueous slurries such as sludge are typically dewatered thermally or through compressive systems such as presses or centrifuges. A new approach to dewatering these slurries is presented and validated. A dilute suspension of sodium polyacrylate (a superabsorbent polymer) in water was pumped through a soaker hose (typically used for irrigation) immersed in the aqueous slurry to be dewatered. Water from the slurry entered the hose through its pores and was absorbed by the acrylate and then continuously pumped out. In the best case the polyacrylate removed 38 times its own weight in water. The soaker hose was used in a reverse configuration, i.e. instead of delivering water to its surroundings, it passively absorbed water from its surroundings and trapped it in the polyacrylate. The spent polyacrylate was subsequently dewatered with supercritical CO2, which displaced the water non-evaporatively from the polymer. The process was illustrated by continuously dewatering alum sludge. Sludge ponds can be potentially dewatered in situ without dredging.

Pseudoboehmite is a hydrated aluminum oxyhydroxide obtained from inorganic precursors by the sol-gel process. It is used as a precursor to alumina and as a reinforcement in obtaining nanocomposites. Cement-reinforced composites with this nanomaterial were obtained in concrete and mortar. Pseudoboehmite with sodium polyacrylate was used to promote a deflocculation of pseudoboehmite particles, which tend to agglomerate in the material. The obtained material was added to the concrete to improve its workability and strength. The new concrete was characterized by slump tests and mechanical tests. Our results revealed that the incorporation of pseudoboehmite with sodium polyacrylate significantly increased the compressive strength and improved the workability of the concrete. Multiple experiments evaluated compressive strength, ultrasound speed, and nanomaterial characterization. Using the Weibull method in mortars, we verified that the pseudoboehmite brought visible benefits as the characteristic stress increased by 17.5%. This increase was observed with the addition of 3% by weight of pseudoboehmite. [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The swelling capacity of novel hydrophilic gaskets used in geomembrane cutoff walls and infrastructures is critical for decreasing the flow rates of contaminated groundwater. This study investigated the swelling behavior, relaxation characteristics, flow rates, and micro-morphology of a hydrophilic gasket with different testing liquids. The radial swelling tests were performed using a device modified from single-lever consolidation instrument. A flow rates model apparatus was manufactured and employed to measure the flow rates of the poor-sealing hydrophilic gasket. According to the test results, the swelling ratio of the hydrophilic gaskets soaked in the DIW were the highest, followed by the NaCl solution, the MSW landfill leachate, and the CaCl2 solution. Relaxation phenomena appeared in all the specimens regardless of the testing liquids. The flow rates of the specimens penetrated with DIW, NaCl, and CaCl2 decreased to a stable state, and then increased extremely slowly to stable values. Moreover, self-healing of the hydrophilic gasket was observed. The micro-morphology indicated that sodium polyacrylate (PAAS) with insufficient expansion could separate from the matrix under high multivalent ionic strength or loading pressure conditions. Therefore, it is critical to develop the modified hydrophilic gasket with resistance to contaminated groundwater for a better barrier performance for use in contaminated sites and infrastructures. [ABSTRACT FROM AUTHOR]

This work proposes a novel approach for colorimetric assays using ubiquitous and inexpensive water beads (WBs) made of a superabsorbent polymer (sodium polyacrylate). The high-water absorption capacity by the WBs was exploited for the preconcentration of iron ions from samples of tap, well, and lake waters. Moreover, the WBs also worked as a substrate for colorimetric detection of iron by the classical reaction of formation of Fe(II)-phenanthroline complex. Digital images acquired with a smartphone were used to obtain the color intensity of the WBs containing the orange color complex. The WBs were able to uptake and preconcentrate iron ions, allowing colorimetric detection with good linearity (R2 = 0.9978) and limits of detection (LOD) and quantification (LOQ) of 0.02 and 0.07 mg L-1, respectively. The proposed method provided recoveries ranging from 93 to 111% for a sample of well water spiked with 0.15 mg L-1 of iron.

A novel green capsule for self-healing cementitious material using a combination of waste-based materials with an inorganic substance was developed. A mix of alum sludge (AS), a typical waste from the water industry, and calcium hydroxide were used as the primary healing agents. Also, two types of natural and synthetic absorbent polymers (AP), microcrystalline cellulose (MCC) and sodium polyacrylate (SPA), were added to the core mixture to assess their impact on the healing efficiency. The morphology of the produced capsules, the self-healing proficiency of cracked mortars, and the resulting healing materials were characterised. Outcomes revealed that cracks up to 400 µm could be healed by the plain capsule. The closure width was dramatically increased to 500 µm and 800 µm with the inclusion of MCC and SPA, respectively, mainly in 3 days. The expansion, water retention, and bridging properties of the APs enhanced the sealing performance of the capsules by providing nucleation sites and increasing the reaction rates of core materials to generate further calcium-based products inside the cracks. Therefore, higher recovery rates of mechanical strengths, along with a significant reduction in water ingress were achieved. The main healing products were identified as calcite crystals, C-S-H, calcium silicate, and aluminium-bearing phases. [Display omitted] • Mix of waste-based sludge and calcium hydroxide used as a green healing agent in capsules. • Impact of two absorbent polymers on healing efficiency of capsules was assessed. • Up to 400 µm crack healing was achieved within 7 days of water curing with plain capsule. • Healing capacity enhanced to 500 µm and 800 µm by addition of absorbent polymers in the capsule mix. • Capsule inclusion significantly increased the mechanical strength and water tightness recoveries. [ABSTRACT FROM AUTHOR]

The flexible optical fiber sensor serves as a prototype for highly sensitive photonic skin flexible sensors (PSFS) with rapid response times, facilitating the development of advanced wearable healthcare devices. Future bionic skin sensors, tailored for wearable devices focusing on health monitoring and robotics applications, will necessitate the incorporation of optical systems. In this work, PSFS based on weak coupling structure is proposed for the first time. This structure comprises a fiber optic sensor with weak coupling as the core sensing node, and the sensing material is hydrophilic and flexible sodium polyacrylate (SPA). The SPA combines the high sensitivity of PSFS with excellent biocompatibility, enabling both static and dynamic sensing measurements for physical parameters such as humidity and temperature. Leveraging the strain amplification effect of the single-mode tapered fiber and the unique fiber structure, the material's sensitivity to relative humidity (RH) is significantly enhanced, reaching 0.19 dB/%RH. Furthermore, the temperature response demonstrates exceptional sensitivity (0.29 dB/℃) within the range of human skin surface temperatures (30–48℃). Remarkably, the sensor has a significant response time of 128 ms. This research proposes a novel approach for constructing highly sensitive and versatile PSFS, which is critical for health care monitoring. [Display omitted] • A weakly coupled photonic skin flexible sensor based on partially neutralized sodium polyacrylate is reported for the first time in this paper. • This photon skin flexible sensor has achieved relative humidity sensing for the first time. • Due to the special fiber structure of weak coupling, the relative humidity sensitivity of the photon skin flexible sensor is as high as 0.19db/%RH, and the fast response time is 128 ms. • The temperature response exhibits outstanding sensitivity (0.29 dB/℃) in the human skin surface temperature range (30–48℃). [ABSTRACT FROM AUTHOR]

Copyright of Uludag University Journal of the Faculty of Engineering (UUJFE) is the property of Uludag Universitesi, Muhendislik Fakultesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The selectivity of biocatalysts based on enzymes, eco-friendly reaction systems, and strong catalyst performance is exceptionally compelling. For improving enzyme recyclability and stability, a good option that has been proved is immobilization. For enzyme immobilization, hydrogel sodium polyacrylate combined with nanoparticles is an interesting class of support matrices as compared to others. This study synthesizes and uses the cross-linked hydrogel sodium polyacrylate-decorated gold or silver nanoparticles (HSP/AuNPs or AgNPs) as immobilized support for peroxidase and FTIR characterizes it. The novel supports immobilized system properties enhanced biocompatibility. They have attained a greater immobilization yield (91% with HSP/AuNPs and 84% with HSP/AgNPs). The rest of the immobilized peroxidase activity, after 10 recurring cycles of HSP/AuNPs was 61% and HSP/AgNPs was 54%. The remaining activity of the immobilized enzyme onto HSP/AgNPs, after storing at 4°C for 6 weeks, was 73% and HSP/AuNPs was 75% of its initial activity. It was revealed that the optimum temperature for the free enzyme and the immobilized enzyme was 50°C and 50–60°C, respectively. For the immobilized enzyme, the optimum pH is 7–7.5, as compared to the optimum pH of free enzyme pH 6.5. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering Geology / Gongcheng Dizhi Xuebao is the property of Journal of Engineering Geology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Robots operating in changing underwater environments may be required to adapt to these varying conditions. In tidal estuaries, for example, where the degree of salinity cycles in step with the level of the water, a robot may need to adapt its behaviour depending on the position of the tide. In freshwater bodies, the unexpected presence of a pollutant may also require the robot to respond by altering its behaviour. Embodying this sensing and response in the body of the robot means that adaptivity to the environment can be achieved without resorting to centralised control. This can also allow direct responsivity using ‘free’ environmental energy, actuating without requiring stored onboard energy. In this work we present a soft artificial muscle, the contraction of which varies in response to the salinity the water surrounding it. The novel actuator uses a super-absorbent polymer gel encapsulated within a series of discrete cells. This gel readily absorbs water through the membrane wall of the actuator, and can swell to over 300 times its initial volume. This swelling generates significant pressure, changing the shape of the cells and driving the contraction of the muscle. The degree of swelling is significantly reduced by the presence of salts and pollutants in the surrounding water, so transitioning from a freshwater to a saltwater environment causes the muscle to relax. In this paper, we discuss the design and fabrication of these superabsorbent polymer-based Bubble Artificial Muscle (SAP-BAM) actuators. The tensile properties of the muscle under actuated (fresh water) and relaxed (salt water) conditions are characterised, showing a maximum generated force of 10.96N. The length response under constant load for a full actuation cycle is given, showing a maximum contraction of 27.5% of the initial length at 1N load, and the performance over repeated actuation and relaxation cycles is shown. The SAP-BAM muscles are straightforward to fabricate and are composed of low-cost, freely-available materials. Many existing pneumatically-actuated muscles can be modified to use the approach taken for this muscle. The muscle presented in this work represents the first example of a new class of super-absorbent polymer-driven environmental soft artificial muscles.

We have synthesized sodium polyacrylate and bentonite supported phosphorous functionalized flame retardant (FR) dough material. The dough material has flame retardant and heat insulator properties. The combination of sodium polyacrylate and bentonite provided strength and flexibility, whereas the phosphorus functionalities contributed the flame retardant property to the FR‐dough. The major benefit of the FR‐dough composite is that it can be simply converted into any 3D shape without the use of any binder and can be easily connected to any surface area without the use of any adhesives. The FR‐dough was successfully applied on the wood stick and electric wire for the flame‐retardant test. These coated materials were sustained on the flame for more than 120 s without any damage, while the only sample burnt out within the 40 s. The flame retardancy and heat resistance properties of the material have been confirmed by conducting a Bunsen burner test as the burner can attain a temperature up to 1500°C. The composite also has smoke absorption and self‐healing properties along with flame retardant and heat resistive properties. This approach has a high potential in the mass production of this multifunctional FR‐dough composite. [ABSTRACT FROM AUTHOR]

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Removing trace water from oil is an important industrial process and is commonly accomplished using vacuum filtration. The drawbacks of this method, however, are: poor efficiency, large oil loss, and significant energy consumption. The objective of the current study was to develop a better system to solve these problems using a sodium polyacrylate (PAA-Na)-modified bentonite as the dehydrating agent and, for the first time, to apply it to transformer oil. PAA-Na was prepared by aqueous solution polymerization. A dehydration test was carried out to determine the optimum addition of PAA-Na, and the highest dehydration rate of 76.5% was obtained with the addition of 20 wt.% PAA-Na. The steady dehydration rate of the PAA-Na-modified bentonite was better than that of other adsorbents (calcium chloride, zeolite 5A, unmodified bentonite). The process of adsorbing saturated water vapor on PAA-Na modified bentonite was studied and interpreted from the aspects of adsorption isotherms and thermodynamic properties. The results showed that the adsorption isotherm data followed the Freundlich isotherm model and the thermodynamic parameters indicated that the process was endothermic. Fourier-transform infrared spectroscopy results revealed that PAA-Na was synthesized successfully and it had a huge proportion of hydrophilic groups. According to thermogravimetric analysis, the PAA-Na-modified bentonite was stable up to 200°C, giving a flexible region for pretreatment and regeneration. X-ray diffraction showed no change in the diffraction pattern before and after modification. Moreover, considering the results of scanning electron microscopy and surface-area analyses, one may safely say that PAA-Na was distributed homogeneously on the surface of the bentonite. In addition, PAA-Na-modified bentonite exhibited a high dehydration rate in xylene, naphtha, and diesel, indicating a broad range of applications. [ABSTRACT FROM AUTHOR]

With increasing pressure from many threats including firefly tourism and urbanization, rearing of Pteroptyx fireflies and reintroducing the species to habitats with low populations is a conservation challenge. Here we report a novel rearing technique for P. valida Olivier, 1909 to develop on an artificial substrate, sodium polyacrylate, together with biological observations on the egg and pupa, stages which are typically difficult to observe. The life span of P. valida under the technique was 152.7 ± 5.2 days and did not differ between sexes. Mated females laid 202.9 ± 17.0 eggs per female with 84% hatching rate. The highest larval mortality rate occurred in the first and second instars with 32% and 25%, respectively. The larvae needed four to six instars to develop to adults. The developmental time of the first to sixth larval instars ranged from 22−32 days, with the pupal stage lasting 9 days. Larvae with additional instars were observed in lab culture, and these most often became female adults, resulting in female-biased sexual size dimorphism as discussed in this study.

Abstract This study aimed to prepare a chelating agent SA-20 using diethylenetriaminepentaacetic acid (DTPA) and low molecular weight sodium polyacrylate raw material for the removal of barium sulfate (BaSO4) scale. The morphology of the resulting chelating agent was characterized by scanning electron microscopy. The BaSO4 scale removal ability of SA-20 was comprehensively evaluated by the dissolving ability, particle size analysis, corrosion performance, and fracture conductivity before and after the scale removal. The results showed that the SA-20 has a good BaSO4 scale removal ability due to the chelation, lattice distortion, and dispersion of DTPA and low molecular weight sodium polyacrylate.

Three types (type-A, B, and C) of composite polymeric membranes (CPMs) based on poly vinyl chloride (PVC) and different fillers (sodium polyacrylate and sodium polyacrylate-graphite) soaked in water and 0.5 N HCl were prepared using solvent casting method. Different physicochemical parameters such as microscopic surface study, water uptake, perpendicular swelling, density, porosity (ε), ion exchange capacity, and conductivity of the as the prepared CPMs were evaluated. Interestingly, type-A CPM cast with filler-A has greater values of the above parameters except density and ionic conductivity than those of type-B and C CPMs. The water uptake of type-A, B and C composite membranes was respectively in the range of 220.42–534.70, 59.64–41.65, and 15.94–2.62%. Ion exchange capacity of type-A, B and C CPMs was in the range of 3.669 × 107–2.156 × 107, 5.948 × 107–1.258 × 107, and 1.454 × 107–1.201 × 107 m.eq.g−1 respectively while the conductivity order was type-A < B < C. These types of CPMs may be helpful in many applications including proton exchange membranes, fuel cell like devices, as sensors for different metals, gas purification, water treatment, and battery separators. [ABSTRACT FROM AUTHOR]