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This review offers an illuminating journey through the historical evolution and modern-day applications of liquid metals, presenting a comprehensive view of their significance in diverse fields. Tracing the trajectory from mercury applications to contemporary innovations, the paper explores their pivotal role in industry and research. The analysis spans electrical switches, mechanical applications, electrodes, chemical synthesis, energy storage, thermal transport, electronics, and biomedicine. Each section examines the intricacies of liquid metal integration, elucidating their contributions to technological advancements and societal progress. Moreover, the review critically appraises the challenges and prospects inherent in liquid metal applications, addressing issues of recycling, corrosion management, device stability, economic feasibility, translational hurdles, and market dynamics. By delving into these complexities, the paper advances scholarly understanding and offers actionable insights for researchers, engineers, and policymakers. It aims to catalyze innovation, foster interdisciplinary collaboration, and promote liquid metal-enabled solutions for societal needs. Through its comprehensive analysis and forward-looking perspective, this review serves as a guide for navigating the landscape of liquid metal applications, bridging historical legacies with contemporary challenges, and highlighting the transformative potential of liquid metals in shaping future technologies., (© 2024 Wiley‐VCH GmbH.)

Healable electronic skins, an essential component for future soft robotics, implantable bioelectronics, and smart wearable systems, necessitate self-healable and pliable materials that exhibit functionality at intricate interfaces. Although a plethora of self-healable materials have been developed, the fabrication of highly conformal biocompatible functional materials on complex biological surfaces remains a formidable challenge. Inspired by regenerative properties of skin, we present the self-assembled transfer-printable liquid metal epidermis (SALME), which possesses autonomous self-healing capabilities at the oil-water interface. SALME comprises a layer of surfactant-grafted liquid metal nanodroplets that spontaneously assemble at the oil-water interface within a few seconds. This unique self-assembly property facilitates rapid restoration (<10 s) of SALME following mechanical damage. In addition to its self-healing ability, SALME exhibits excellent shear resistance and can be seamlessly transferred to arbitrary hydrophilic/hydrophobic curved surfaces. The transferred SALME effectively preserves submicron-scale surface textures on biological substrates, thus displaying tremendous potential for future epidermal bioelectronics., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Nano zero-valent (nZVI) based composite have been widely utilized in environmental remediation. However, the rapid agglomeration and quick deactivation of nZVI limited its application on large scale. In this work, CaCO 3 supported nZVI-Ni catalyst, namely nZVI-Ni@CaCO 3 was prepared and used for the efficient removal of trichloroethylene (TCE) in PS oxidation process. The successful disbursement of nZVI-Ni on CaCO 3 support material not only increased the surface area of nZVI-Ni@CaCO 3 (69.45 m 2 /g) with respect to CaCO 3 (5.92 m 2 /g) and bare nZVI (13.29 m 2 /g) but also improved the catalytic activity. XRD, XPS and FTIR analysis confirmed the successful formation of nZVI-Ni@CaCO 3 nanoparticles. The nZVI-Ni@CaCO 3 nanoparticles combined with PS had achieved complete removal of TCE (99.8%) with dosage of 36 mg/L and 1.34 mM respectively. These results showed that the use of CaCO 3 as support material for nZVI-Ni could have significant influence on contaminant removal process. Scavenging and EPR tests validated the existence of SO 4 •- , OH • and O 2 •- radicals in PS/nZVI-Ni@CaCO 3 system and highlighted the dominant role of SO 4 •- radicals in TCE removal process. HCO 3 - ions and humic acid have shown adverse effect on TCE removal due to radical scavenging and buffering effect. Owing to improved catalytic activity and easy preparation, the nZVI-Ni@CaCO 3 nanoparticles could be served as an alternative strategy for environmental remediation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Pectin-crosslinked gum ghatti hydrogel (PGH) has been synthesized utilizing pectin and gum ghatti through an uncomplicated and inexpensive copolymerization method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM-elemental mapping), Brunauer-Emmett-Teller (BET), and X-ray photoelectron spectroscopy (XPS) characterization techniques have been employed to determine various structural, chemical and compositional characteristics of fabricated PGH. Three different weight ratios (1:1, 2:1, or 1:2 for pectin and gum ghatti, respectively) were employed to synthesize three distinct types of PGH. Swelling studies has been done to determine the best ratios for PGH fabrication. PGH has been assessed as an adsorbent for the removal of malachite green dye from aqueous solutions. The effects of PGH dosage (100-400 mg/L), dye concentration (10-160 mg/L), pH (2-9 pH), adsorption time (0-480 min), and temperature (25-55 °C) has been examined through batch solutions. According to Langmuir isotherm analysis, the maximum adsorption capacity is 658.1 mg/g. By using pseudo-second-order kinetics and the Freundlich adsorption isotherm, the adsorption process could be well explained. After five consecutive cycles, PGH had an adsorption percentage of 86.917 % for the malachite green dye. It is safe for the environment and may be used to remove malachite green (MG) dye from aqueous solutions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

There is a high demand for an optimal drug delivery system to treat androgenetic alopecia. Topical application of ISX9, which is a neurogenesis inducer, has been found to stimulate hair follicle (HF) regrowth by upregulating the Wnt/β-catenin signaling pathway, an essential pathway involved in initiating HF growth and development. In the present study, a temperature-sensitive, biopolymer-based, biocompatible, and eco-friendly drug-delivery system was synthesized. This system comprised chitosan-grafted poly(glycidyl methacrylate- co -N-isopropyl acrylamide) (Poly(GMA- co -NIPAAm)@CS-PGNCS) as the shell component and PF127 as the core polymer. The hydrophobic nature of the PF127 block copolymer efficiently dissolved the partially water-soluble drug, ISX9, and the thermos-responsive shell polymer effectively released the drug at a definite skin temperature. The optimized spherical nanoparticles demonstrated the lowest critical solution temperature (LCST) at 32 ± 2 °C with a diameter of 100-250 nm, which delivered encapsulated ISX9 with greater precision than topical ISX9. In a series of in vivo experiments, we demonstrated that ISX9-coated TBNPs upregulated the expression of β-catenin, active β-catenin, Wnt target genes, stemness marker genes, proliferating cell nuclear antigen, HF stem cell markers, and HF markers including VEGF, TGF, and IGF-1 more effectively than topical ISX9. These results suggest that TBNPs could be employed as a platform for effective transdermal delivery of various hydrophobic drugs., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

The dramatic rise in carbon dioxide levels in the atmosphere caused by the continuous use of carbon fuels continues to have a significant impact on environmental degradation and the disappearance of energy reserves. Past few years have seen a significant increase in the interest in photocatalytic carbon dioxide reduction because of its ability to lower CO 2 releases from the burning of fossil fuels while also producing fuels and important chemical products. Because of their excellent catalytic efficiency, great uniformity, lengthy charge diffusion layers and texture flexibility that enable accurate band gap and band line optimization, perovskite-based nanomaterials are perhaps the most advantageous among the numerous semiconductors proficient in accelerating CO 2 conversion under visible light. Firstly, a brief insight into photocatalytic CO 2 conversion mechanism and structural features of perovskites are discussed. Further the classification and selection of perovskites for Z and S-scheme heterojunctions and their role in photocatalytic CO 2 reduction analysed. The efficient modification and engineering of heterojunctions via co-catalyst loading, morphology control and vacancy introduction have been comprehensively reviewed. Third, the state-of-the-art achievements of perovskite-based Z-scheme and S-scheme heterojunctions are systematically summarized and discussed. Finally, the challenges, bottlenecks and future perspectives are discussed to provide a pathway for applying perovskite-based heterojunctions for solar-to-chemical energy conversion., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The present paper describes the design of shape-oriented hydrogel nanospheres using a facile ultrasonication-supported crosslinked copolymerization technique. The effect of variable monomer concentration on the homogeneity of hydrogel nanospheres was investigated. The chitosan- cl -poly(MMA) hydrogel nanospheres were well characterized using various techniques such as FTIR, XRD, TGA, SEM, and TEM. The chitosan- cl -poly(MMA) hydrogel nanospheres were studied for their swelling behavior and could potentially be used as a novel adsorbent for rhodamine B dye remediation from aqueous media. The study found that utilizing chitosan-cl-poly(MMA) nanohydrogel spheres at the optimal pH 5 increased RhB dye adsorption capacity from 7.9 to 17.8 mg/g (pH 2 to 5), followed by a slight reduction. Furthermore, when nanohydrogel concentration increased, adsorption capacity dropped from 18.03 to 2.8 mg/g, but adsorption percentage climbed from 90.2% to 97.8%. At an initial dye concentration of 140 mg/L, rhodamine B adsorption achieved 204.3 mg/g in 60 min. The rhodamine B dye adsorption study includes adsorption kinetics, isotherm, and thermodynamics analyses. The interpretation of the adsorption study revealed that Langmuir isotherms fit best with a qmax value of 276.26 mg/g, which is in close approximation with the experimental value, whereas pseudo-second-order kinetics explains the adsorption process rate. The interaction of RhB dye with chitosan- cl -poly(MMA) hydrogel nanospheres involves multiple forces such as electrostatic interactions, hydrogen bonding, van der Waals forces, etc.

Ionic liquids (ILs)-incorporated solid-state polymer electrolytes (iono-SPEs) have high ionic conductivities but show non-uniform Li + transport in different phases. This work greatly promotes Li + transport in polymer phases by employing a poly (vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) [P(VDF-TrFE-CTFE), PTC] as the framework of ILs to prepare iono-SPEs. Unlike PVDF, PTC with suitable polarity shows weaker adsorption energy on IL cations, reducing their possibility of occupying Li + -hopping sites. The significantly higher dielectric constant of PTC than PVDF facilitates the dissociation of Li-anions clusters. These two factors motivate Li + transport along PTC chains, narrowing the difference in Li + transport among varied phases. The LiFePO 4 /PTC iono-SPE/Li cells cycle steadily with capacity retention of 91.5 % after 1000 cycles at 1 C and 25 °C. This work paves a new way to induce uniform Li + flux in iono-SPEs through polarity and dielectric design of polymer matrix., (© 2023 Wiley-VCH GmbH.)

Pickering emulgels stabilized by graphene oxide (GO) with didodecyldimethylammonium bromide (DDAB) as an auxiliary surfactant and liquid paraffin as the oil phase have proved to be an excellent 3D printable ink. This paper elucidates the structure of such emulgels by a combination of microscopy before and after intensive shear as well as broadband dielectric spectroscopy and rheology in the linear and nonlinear regime. An increase of the DDAB surfactant and GO-contents leads to a systematic increase of modulus and viscosity, a reduction of the limits of the nonlinear regime and a more complicated variation of the normal forces, with negative normal forces at high shear rate  for low GO-contents and positive normal forces at high GO-contents. The interfacial jamming behavior studied by morphology, rheology and dielectric spectroscopy is explained based on droplet deformation, jamming and recovery phenomena.

This study investigates the rheological properties of dual-network hydrogels based on acrylamide and sodium alginate under large deformations. The concentration of calcium ions affects the nonlinear behavior, and all gel samples exhibit strain hardening, shear thickening, and shear densification. The paper focuses on systematic variation of the alginate concentration-which serves as second network building blocks-and the Ca 2+ -concentration-which shows how strongly they are connected. The precursor solutions show a typical viscoelastic solution behavior depending on alginate content and pH. The gels are highly elastic solids with only relatively small viscoelastic components, i.e., their creep and creep recovery behavior are indicative of the solid state after only a very short time while the linear viscoelastic phase angles are very small. The onset of the nonlinear regime decreases significantly when closing the second network (alginate) upon adding Ca 2+ , while at the same time the nonlinearity parameters (Q 0 , I 3 /I 1 , S, T, e 3 /e 1 , and v 3 /v 1 ) increase significantly. Further, the tensile properties are significantly improved by closing the alginate network by Ca 2+ at intermediate concentrations.

Hybrid hydrogels based on n-isopropylacrylamide, zwitterionic comonomer, and graphene oxide were synthesized to study their physical and mechanical properties. The compositional variation largely influenced the swelling characteristics of the hybrid hydrogels compared to mechanical properties, i.e., elongation and compression. Additionally, Rheometric swelling measurements on the swollen hydrogels were performed until they reached equilibrium showed a very low phase angle δ indicating strong covalent network, which intrun increases with increasing content of zwitterions and GO. Swelling kinetics were studied and found to follow Fickian dynamics, albeit zwitterion-containing gels showed a peculiar 2-step swelling pattern. Interestingly, differences in the swelling mechanism are also clear for the hydrogels with 2D GO (Graphene oxide) nano-fillers from its 1D nano-filler CNTs (Carbon nanotubes). In elongation, the samples break in a brittle fashion at Hencky strains ε max around 0.4-0.65 with the maximum stress being observed for samples with high Zw-content and 0.2% GO, which can be explained by the stress-rising properties of sharp edges of GO. In contrast, the data in compression profits from higher GO-contents as crack growth is less important in this deformation mode. This work will contribute to future composite gel applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Biopolymer-based conductive hydrogels (HGs) are promising candidates for preparing environmentally friendly flexible electronics. However, it is still a great challenge to synthesize biopolymer-based tough, self-healable, and fast strain recoverable HGs. Herein, a facile strategy is demonstrated to synthesize stretchable, self-recoverable, conductive, and tough HGs strain sensors through the formation of multi-dynamic interactions (i.e., imine bond formation, hydrogen bonds, ionic bonds, and electrostatic bonds) and strong covalent interactions between MXene (Ti 3 C 2 T x ), oxidized sodium alginate (OSA), chitosan (CS), polyacrylamide (PAAm), Fe(III) and PEDOT:PSS. Thus, obtaining dynamically and covalently bonded nanocomposite hydrogels (NCHGs) with controllable interfacial interactions exhibited a high mechanical strength (0.91 MPa), toughness (2.99 MJ/m 3 ), stretchability (820 %), elasticity (>600 %) and conductivity (1.31 S/m). In addition, the presence of Fe(III) ions and conducting fillers endows excellent repeatability with high stability in resistance change upon bending or stretching with ultra-broad sensitivity up to 11-gauge factor and consisting lowest resistance change up to 0.5 %., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

The dispersibility of flexible polymer chains present at the emulsion's interface between the dispersed and continuous phase has obvious effects on rheology and dielectric properties of the whole emulsion. Cellulose nanofiber (CNF)-based Pickering emulsions are good systems to research these properties with respect to their microscopic phase structure, dielectric, and rheological properties by using CNF as a water-dispersible Pickering emulsifier, liquid paraffin as an oil phase, and didodecyldimethylammonium bromide (DDAB) as a cationic auxiliary surfactant. The CNF and DDAB contents were systematically varied while the water-to-paraffin oil ratio was kept constant to discern the influence of the Pickering emulsifiers. Polarized optical microscopic images reveal that the droplets tend to shrink at higher CNF content but grow bigger when increasing the DDAB content, which is proved by fluorescence analysis of the CNF dispersibility with varying DDAB content. The dielectric damping exhibits a minimum, whose value decreases with increasing DDAB and CNF content. Increasing the DDAB content promotes the solubilization of CNF in the aqueous phase, which will increase the overall viscosity and yield points. Similarly, a higher CNF content leads to a higher viscosity and yield point, but at high DDAB contents, the viscosity function exhibits an S-shape at intermediate CNF contents. To evaluate the results further, they were compared with CNF dispersions (without oil phase), which showed a surfactant effect slightly on maximum stress but strongly on yield stress τy, indicating that DDAB can promote the formation of a CNF network rather than the viscosity of the whole system. This paper provides information on how a systematical variation of the composition influences morphology and physico-chemical interactions as detected by broadband dielectric spectroscopy and rheological behavior.

In the present study, we have successfully formulated a dual heterojunction of g-C 3 N 4 /BiOCl@MXene-Ti 3 C 2 (GCBM) which was found to be highly active in the visible region. GCBM was found to be highly efficient for the degradation of an antibiotic, tetracycline (TC) as compared to the individual constituting units; g-C 3 N 4 and BiOCl. Maximum of 97% TC degradation rate was obtained within 90 min of visible light irradiation for initial concentration of 10 mg/L of TC. Optical analysis exhibited that the synthesized heterojunction showed high absorption in the complete spectrum. The reactive species specified by the scavenger study showed the major involvement of • O 2 - and • OH radicals. The charge transfer mechanism showed that 2 schemes were majorly involvement in which Z-scheme was formed between g-C 3 N 4 and BiOCl and Schottky junction was formed between g-C 3 N 4 and Mxene-Ti 3 C 2 . The formation of Schottky junction helped in inhibiting the back transfer of photogenerated charges and thus, helped in reducing the recombination rate. The synthesized photocatalyst was found to be highly reusable and was studied for consecutive 5 cycles that generalized the high proficiency even after repetitive cycles., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

After several billions of years, nature still makes decisions on its own to identify, develop, and direct the most effective material for phenomena/challenges faced. Likewise, and inspired by the nature, we learned how to take steps in developing new technologies and materials innovations. Wet and strong adhesion by Mytilidae mussels (among which Mytilus edulis -blue mussel and Mytilus californianus -California mussel are the most well-known species) has been an inspiration in developing advanced adhesives for the moist condition. The wet adhesion phenomenon is significant in designing tissue adhesives and surgical sealants. However, a deep understanding of engaged chemical moieties, microenvironmental conditions of secreted proteins, and other contributing mechanisms for outstanding wet adhesion mussels are essential for the optimal design of wet glues. In this review, all aspects of wet adhesion of Mytilidae mussels, as well as different strategies needed for designing and fabricating wet adhesives are discussed from a chemistry point of view. Developed muscle-inspired chemistry is a versatile technique when designing not only wet adhesive, but also, in several more applications, especially in the bioengineering area. The applications of muscle-inspired biomaterials in various medical applications are summarized for future developments in the field., Competing Interests: There is no conflict of interest to declare., (© 2022 The Authors. Bioengineering & Translational Medicine published by Wiley Periodicals LLC on behalf of American Institute of Chemical Engineers.)

New developments require innovative ecofriendly materials defined by their biocompatibility, biodegradability, and versatility. For that reason, the scientific society is focused on biopolymers such as chitosan, which is the second most abundant in the world after cellulose. These new materials should show good properties in terms of sustainability, circularity, and energy consumption during industrial applications. The idea is to replace traditional raw materials with new ecofriendly materials which contribute to keeping a high production rate but also reducing its environmental impact and the costs. The chitosan shows interesting and unique properties, thus it can be used for different purposes which contributes to the design and development of sustainable novel materials. This helps in promoting sustainability through the use of chitosan and diverse materials based on it. For example, it is a good sustainable alternative for food packaging or it can be used for sustainable agriculture. The chitosan can also reduce the pollution of other industrial processes such as paper production. This mini review collects some of the most important advances for the sustainable use of chitosan for promoting circular economy. Hence, the present review focuses on different aspects of chitosan from its synthesis to multiple applications.

Herein, we report the designing of a C 3 N 4 /BiOI heterostructure that is supported on gum acacia-crosslinked-poly(acrylamide) hydrogel to fabricate a novel nanocomposite hydrogel. The potential application of the obtained nanocomposite hydrogel to remediate crystal violet dye (CVD) in an aqueous solution was explored. The structural and functional analysis of the nanocomposite hydrogel was performed by FTIR (Fourier transform infrared spectroscopy), X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The different reaction parameters, such as CVD concentration, nanocomposite hydrogel dosage, and working pH, were optimized. The C 3 N 4 /BiOI heterostructure of the nanocomposite hydrogel depicts Z-scheme as the potential photocatalytic mechanism for the photodegradation of CVD. The degradation of CVD was also specified in terms of COD and HR-MS analysis was carried to demonstrate the major degradation pathways.

Rapid industrial development is associated with high discharge of toxic pollutants into the environment. The industries discharge their wastewater containing organic pollutants directly into the water system without treating them that has posed many serious threats to environmental protection. The use of bioadsorbents for the removal of such toxic pollutants from the waste water due to its simple synthesis, easy operation, effectiveness, and economic viability have emerged a new dimension in the wastewater treatment approaches. Various adsorbents have been prepared to examine their adsorption capacity against different adsorbates, but, to attain sustainability, biocompatibility, and biodegradation, bio-adsorbents have been found to won the battle. Seaweed derived polysaccharide; Carrageenan (CR) has been proven to be an excellent adsorbent for the wastewater treatment. It has been successfully modified with various components to form CR based-magnetic composites, hydrogels, nanoparticle modified CR composites and many others to enrich and diversify its properties. In this review, we have explained the adsorption behaviour of various carrageenan based adsorbents for the removal of different dyes. The influence of various parameters such as the effect of initial concentration, adsorbent dosage, contact time, pH, temperature, and ion concentration on dye adsorption is well explained. This paper also summarizes the structure, morphology, swelling ability, and thermal stability of carrageenan. The data also expounds on the adsorption capacity, kinetic model, isotherm model, and nature of the adsorption process. Different types of solvents are used for the regeneration and reusability of carrageenan adsorbents and their regeneration studies and desorption efficiency is well-explained. The adsorption mechanism of dyes onto carrageenan based adsorbents has been well described in this review. This review provides a deep insight about the use of carrageenan based adsorbents for the wastewater treatment., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Polysaccharide-based hydrogels offer a great overlook for environmental applications and help in the elimination of various noxious pollutants from the water system. Novel carrageenan and itaconic acid-based superadsorbent hydrogel having appreciable swelling properties and adsorption capacity towards Methylene blue (MB), Crystal violet (CV), and Methyl Red (MR) was synthesized by suspension polymerization technique. The swelling study showed the dependency upon the temperature in which the swelling rate increased with increasing temperature with a maximum swelling rate of 417% at 318 K. For ascertaining the maximum adsorption capacity, various influential parameters such as contact time, adsorbent dose, dye concentration, and temperature were systematically studied. Maximum adsorption capacity as calculated from the Langmuir isotherm was 2439.02, 1111.11, and 666.68 mg/g for MB, CV, and MR, respectively. Thermodynamic studies revealed the spontaneous nature of the undertaken dye adsorption experiment. Overall, the present study reveals that the synthesized superadsorbent hydrogel can be used as an efficient adsorbent for the removal of dyes from an aqueous solution., (Copyright © 2021 Elsevier B.V. All rights reserved.)

New emerging technologies, remarkably miniaturized 3D organ models and microfluidics, enable simulation of the real in vitro microenvironment ex vivo more closely. There are many fascinating features of innovative organ-on-a-chip (OOC) technology, including the possibility of integrating semipermeable and/or stretchable membranes, creating continuous perfusion of fluids into microchannels and chambers (while maintaining laminar flow regime), embedding microdevices like microsensors, microstimulators, micro heaters, or different cell lines, along with other 3D cell culture technologies. OOC systems are designed to imitate the structure and function of human organs, ranging from breathing lungs to beating hearts. This technology is expected to be able to revolutionize cell biology studies, personalized precision medicine, drug development process, and cancer diagnosis/treatment. OOC systems can significantly reduce the cost associated with tedious drug development processes and the risk of adverse drug reactions in the body, which makes drug screening more effective. The review mainly focus on presenting an overview of the several previously developed OOC systems accompanied by subjects relevant to pharmacy-, cancer-, and placenta-on-a-chip. The challenging issues and opportunities related to these systems are discussed, along with a future perspective for this technology., (© 2021 Wiley-VCH GmbH.)

Designing and fabrication of smart hybrid multifunctional materials for energy/fuel production and environmental detoxification is indeed of great significance for sustainable development. Herein, we synthesized a new well-structured S-scheme heterostructure Fe@TiO 2 /Boron Carbon nitride (FT/BCN) with high performance tetracycline degradation and selective CO 2 photo-reduction to CH 4 . Under visible light irradiation, 96.3% tetracycline was degraded in 60 min using best performing FT30/BCN sample with a high 83.2% total organic carbon removal in 2 h. The tetracycline degradation rate for FT30/BCN composite catalyst was ∼7 times than bare boron carbon nitride (BCN). The impact of reaction parameters as pH, presence of interfering electrolytes, light source and water matrix was also investigated. The FT30/BCN photocatalyst shows dramatic improvement in CO 2 photoreduction as exhibited in 24.7 μmol g -1 h -1 CH 4 and 2.4 μmol g -1 h -1 CO evolutions with optimal 91.1% CH 4 selectivity. Pure BCN shows a poor 39.1% selectivity. Further, effect of alkali activation, CO 2 /H 2 O feed ratio, reducing agent and light source onto CH 4 production and selectivity was also investigated. The CH 4 evolution and selectivity was improved because of enhanced visible light absorption, high adsorption potential, charge carrier separation and high reducing power of photogenerated electrons induced by an effective S-scheme heterojunction between Fe@TiO 2 and boron carbon nitride. An S-scheme (step-scheme) charge transfer mechanism is here operative both during tetracycline removal and CO 2 reduction. The drug degradation route and photocatalytic mechanism for antibiotic removal and CO 2 reduction was also predicted., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The present research demonstrates the facile fabrication of xanthan gum-cl-poly(acrylamide-co-alginic acid) (XG-cl-poly(AAm-co-AA)) hydrogel by employing microwave-assisted copolymerization. Simultaneous copolymerization of acrylamide (AAm) and alginic acid (AA) onto xanthan gum (XG) was carried out. Different samples were fabricated by changing the concentrations of AAm and AA. A sample with maximum swelling percentage was chosen for adsorption experiments. The structural and functional characteristics of synthesized hydrogel were elucidated using diverse characterization tools. Adsorption performance of XG-cl-poly(AAm-co-AA) hydrogel was investigated for the removal of noxious cadmium (Cd(II)) ions using batch adsorption from the aqueous system, various reaction parameters optimized include pH, contact time, temperature, and concentration of Cd(II) ions and temperature. The maximum adsorption was achieved at optimal pH 7, contact time 180 min, temperature 35 °C and cadmium ion centration of 10 mg·L -1 . The XG-cl-poly(AAm-co-AA) hydrogel unveiled a very high adsorption potential, and its adsorption capacities considered based on the Langmuir isotherm for Cd(II) ions was 125 mg·g -1 at 35 °C. The Cd(II) ions adsorption data fitted nicely to the Freundlich isotherm and pseudo-first-order model. The reusability investigation demonstrated that hydrogel retained its adsorption capacity even after several uses without significant loss.

The functionalization of smart polymers is opening a new perspective in catalysis, drug carriers and biosensors, due to the fact that they can modulate the response regarding conventional devices. This smart response could be affected by the presence of organometallic complexes in terms of interactions which could affect the physical chemical properties. In this sense, the thermoresponsive behavior of copolymers based on N -isopropylacrylamide (NIPAM) could be affected due to the presence of hydrophobic groups and concentration effect. In this work, the functionalization of a copolymer based on NIPAM and dopamine methacrylamide with different amounts of bis(cyclopentadienyl)titanium (IV) dichloride was carried out. The resulting materials were characterized, showing a clear idea about the mechanism of functionalization through FTIR spectroscopy. The thermoresponsive behavior was also studied for various polymeric solutions in water by UV-vis spectroscopy and calorimetry. The hydrophobic interactions promoted by the organometallic complex could affect the transition associated with the lower critical solution temperature (LCST), specifically, the segments composed by pure NIPAM. That fact would explain the reduction of the width of the LCST-transition, contrary to what could be expected. In addition, the hydrophobicity was tested by the contact angle and also DNA interactions.

This work was designed to evaluate the efficacy of hyaluronic acid (HA) functionalized tubular poly-lactic acid (PLA) microfibers in directing the luminal pre-endothelialization of vascular endothelial cells (ECs). Tubular HA/PLA microfibers with hierarchical architecture were prepared by electrospinning and chemical cross-linking process. A layer of HA microfibrous film coating was fixed on the inner wall surface of the tubular HA/PLA microfibers, resulting in higher anisotropy wettability and relatively lower surface energy and roughness. We confirmed that HA coating on PLA microfibers surface have reduced hemolytic activity and coagulation degree. Mouse vascular ECs exhibited surface-dependent differences in cell elongation and proliferation (HA/PLA > PLA). Compared with PLA microfibers, the gene expression levels of platelet EC adhesion molecule-1 (PECAM-1/CD31) and vascular endothelial growth factor (VEGF) in ECs of HA/PLA microfibers surface were up-regulated. Immunostaining analysis revealed that the surface of HA/PLA nanofibers supported the expression of mature vascular EC phenotype CD31 protein. In vitro co-culture analysis showed that the luminal pre-endothelialization induced vascular smooth muscle cells (SMCs) to maintain their phenotypic shape and establish natural behavior patterns in the hierarchical tubular scaffold. These studies indicate that the biophysical cues of scaffolds are potent regulators of vascular EC endothelialization., (Copyright © 2021. Published by Elsevier B.V.)

In situ tissue engineering utilizes the regenerative potential of the human body to control cell function for tissue regeneration and has shown considerable prospect in urology. However, many problems are still to be understood, especially the interactions between scaffolds and host macrophages at the wound site and how these interactions direct tissue integration and regeneration. This study was designed to evaluate the efficacy of hyaluronic acid (HA) functionalized collagen nanofibers in modulating the pro-healing phenotype expression of macrophages for urethral regeneration. Tubular HA-collagen nanofibers with HA-coating were prepared by coaxial electrospinning. The formation of a thin HA-coating atop each collagen nanofiber endowed its nanofibrous mats with higher anisotropic wettability and mechanical softness. The macrophages growing on the surface of HA-collagen nanofibers showed an elongated shape, while collagen nanofibers' surface exhibited a pancake shape. Immunofluorescence and ELISA analysis showed that elongation could promote the expression of M2 phenotype marker and reduce the secretion of inflammatory cytokines. In vivo experiments showed that tubular HA-collagen nanofibers significantly facilitate male puppy urethral regeneration after injury. In the regenerated urethra bridged by tubular HA-collagen nanofibers, anti-inflammatory M2 macrophages are recruited to the surface of the scaffold, which can promote angiogenesis and endogenous urothelial progenitor cell proliferation., (© 2021. The Author(s).)

In the present work, the removal of fast sulphon black (FSB) dye from water was executed by using chitin-cl-poly(itaconic acid-co-acrylamide)/zirconium tungstate nanocomposite hydrogel (Ch-cl-poly(IA-co-AAm)-ZrW NCH). The Ch-cl-poly(IA-co-AAm)-ZrW NCH was fabricated proficiently by microwave-induced sol-gel/copolymrization method. The zirconium tungstate (ZrW) photocatalyst was prepared by co-precipitation method using sodium tungstate and zirconium oxychloride in ratio (2:1). The polymeric hydrogel part has been used to support the ZrW, and it acted as an adsorbent for adsorptive removal of FSB dye. The band gap for nanocomposite hydrogel was found about 4.18 eV by using Tauc equation. The Ch-cl-poly(IA-co-AAm)-ZrW NCH was characterized by various techniques as FTIR (Fourier-transform infrared spectroscopy), X-ray diffraction (XRD), transmittance electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM). The adsorptional-photocatalytic remediation experiment of FSB dye was optimized for reaction parameters as FSB dye and Ch-cl-poly(IA-co-AAm)-ZrW NCH concentration, and pH. The maximum percentage removal for FSB dye was observed at 92.66% in 120 min under adsorptional-photocatalysis condition., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Gallium-based alloys have garnered considerable attention in the scientific community, particularly as they are in an atypical liquid state at and near room temperature. Though physical parameters, such as thermal conductivity, electrical conductivity, viscosity, yield stress, and surface tension, of these alloys are broadly known, the surface tension (surface free energy) of the oxide skin remains intangible due to the high yield stress of the oxide skin. In this article, we propose to employ gradually attenuated vibrations to obtain equilibrium shapes, which are analyzed along the lines of the puddle height method. The surface tension of the oxide skin was determined on quartz glass and liquid metal-phobic diamond coating to be around 350-365 mN/m, thus independent of the substrate surface or employed liquid metal (i.e., eutectic Ga-In (EGaIn) and galinstan). The similarity of the surface tension for different alloys was ascribed to the composition of the oxide skin, which predominantly comprises gallium oxides due to thermodynamic constraints. We envision that this method can also be applied to other liquid metal alloys and liquid metal marble systems facilitating modeling, simulation, and optimization processes.

The water resources contamination in an alarming concern for sustainable environment. This has led to development of new technologies and materials for waste water detoxification. In the present study, we have fabricated novel trimetallic based mixed oxides decorated reduced graphene oxide (rGO) composite using facile microwave method and utilized it as an adsorbent for the removal of congo red dye from aqueous solution. The final composite showed highly agglomerated metal oxides present on the rGO surface. The high surface area and activity of the synthesized adsorbent resulted in its high adsorption capacity of 333.32 mg/g for congo red. The Langmuir model better explained the isotherm data indicating the monolayer adsorption of congo red molecules onto Ag 2 O-Al 2 O 3 -ZrO 2 /rGO surface. The grander adsorption ability of Ag 2 O-Al 2 O 3 -ZrO 2 /rGO towards organic dye indicate its probable utilization in the removal of other dyes also from wastewater., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Due to the impact of toxic gases on human health, considerable interest has been shown in detecting noxious air pollutants, particularly sulfur dioxide (SO 2 ), both experimentally and theoretically. This work provides new insights into the adsorbing (SO 2 ) molecules on the surface of metal-oxide graphitic structures, i.e., Beryllium-Oxide (BeO), Zinc-Oxide (ZnO), and Ni-decorated graphene applying a first-principles study. Computational analyses suggest that the type of binding of SO 2 molecule on BeO and ZnO sheets is physisorption so that binding energies of -0.405 and -0.154 eV were assigned to ZnO and BeO nanosheets in that order. The adsorption energy of SO 2 on metal oxide sheets was much higher than the pristine graphene. Taking pristine graphene as an adsorbent for SO 2 molecule, it was found that such nanomaterial is not an efficient adsorbent due to the weak interactions (-0.157 eV) and low electron charge transfer (0.042 e) present in SO 2 /graphene complex. To overcome this issue, graphene nanosheets decorated with nickel atoms were studied for interaction with SO2 molecules; the results indicate that the SO 2 molecules were chemisorbed on Ni-decorated graphene sheets with an adsorption energy of -2.297 eV. Chemisorption of SO 2 molecules on Ni-decorated graphene sheets was proven by the strong orbital hybridization between Ni 3d and sulfur 3p orbitals in the Projected Density of States (PDOS) plot. This work provides useful information about SO 2 adsorption on Ni-decorated graphene sheets in order to develop a new class of gas sensing devices. Superior chemisorption of SO 2 on Ni-decorated graphene sheets compared to the physical adsorption on BeO and ZnO sheets makes Ni-decorated graphene a potential candidate for detecting SO 2 molecules.

The micro- or nanoscale surface morphology of the tissue engineering nerve guidance scaffold (NGS) will affect different cell behaviors, such as their growth rate, migration, and matrix secretion. Although different technologies for manufacturing scaffolds with biomimetic topography have been established, most of them tend to be high cost and long preparation time. Here we have prepared a biomimetic NGS with physical properties to simulate native nerve tissue more accurately. We used poly(l-lactic acid) (PLLA) nanofibers doped with gelatin to prepare a biomimetic NGS whose structure mimics the native epineurium layer. By adjusting the doping ratio of gelatin and PLLA in the tubular scaffold, the bionic scaffold's surface morphology and mechanical properties are closer to native tissues. In vitro cell scaffold interaction experiments demonstrated that the PLLA/gelatin nanofibers could significantly promote the elongation, proliferation, and the secretion of glial cell-derived neurotrophic factor (GDNF) of RSC96 Schwann cells (SCs), as well as the diffusion of GDNF. In vivo scaffold replacement of SD rat, sciatic nerves showed that the nerve guide scaffold composed of PLLA/gelatin nanofibers was helpful to the myelination of SCs and the remolding of epineurium in the injured area, which could effectively rehabilitate the motor and sensory functions of the injured nerve and prevent the atrophy of the target muscle tissue. This study showed that the synergistic impact of nano topographical and biochemical clues on designing biomimetic scaffolds could efficiently promote regenerating nerve tissue., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Long-chain branched metallocene-catalyzed high-density polyethylenes (LCB-mHDPE) were solution blended to obtain blends with varying degrees of branching. A high molecular LCB-mHDPE was mixed with low molecular LCB-mHDPE at varying concentrations. The rheological behavior of those low molecular LCB-mHDPE is similar but their molar mass and molar mass distribution are significantly different. Those blends were characterized rheologically to study the effects of concentration, molar mass distribution, and long-chain branching level of the low molecular LCB-mHDPE. Owing to the ultra-long relaxation times of the high molecular LCB-mHDPE, the blends exhibited a clearly more long-chain branched behavior than the base materials. The thermorheological complexity analysis showed an apparent increase in the activation energies E a determined from G' , G″ , and especially δ. E a (δ), which for LCB-mHDPE is a peak function, turned out to produce even more pronounced peaks than observed for LCB-mPE with narrow molar mass distribution and also LCB-mPE with broader molar mass distribution. Thus, it is possible to estimate the molar mass distribution from the details of the thermorheological complexity.

Focusing on the treatment of pharmaceuticals contaminated water by advanced oxidation processes, a novel three dimensional silicate glass matrix (3-DG) coupled Cu 2 O/Cu 2 V 2 O 7 p-n heterojunction was constructed by in-situ hydrothermal technique. The optimal Cu 2 O/Cu 2 V 2 O 7 with 30 wt % Cu 2 V 2 O 7 (CV-30) degrades 90.1 % sulfamethoxazole (SMX) in 60 min and nearly 100 % removal in 45 min via coupling with 3-DG. Under natural sunlight ∼ 80 % SMX removal was observed. The internal electric field of the p-n junction facilitates the electron flow via the interface. 3-D silicate glass increases the visible light absorption dramatically via internal reflection which facilitates higher exposure for the junction and shortens the diffusion length of charge carriers. The effect of reaction parameters suggests that HCO 3 - and CO 3 2- ions substantially escalate the SMX removal rate. Scavenging experiments and ESR probe suggest O 2 - as the main active species followed by OH radicals. The degradation products were detected by LC-MS analysis and a degradation mechanism was also predicted. The photocatalytic mechanism was explained in terms of the electron transfer facilitated by conventional transfer and Z-scheme. This strategy to construct such highly visible and solar active p-n heterojunctions will pave way for future opportunities for the degradation of recalcitrant pharmaceutical pollutants., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Three-dimensional (3D) nanocomposite (NC) printing has emerged as a major approach to translate nanomaterial physical properties to 3D geometries. However, 3D printing of conventional NCs with polymer matrix lacks control over nanomaterial connection that facilitates maximizing nanomaterial advantages. Thus, a printable NC that features nanomaterials matrix necessitates development, nevertheless, faces a challenge in preparation because of the trade-off between viscosity and interfacial stability. Here, we develop viscoelastic Pickering emulgels as NC inks through jamming nanomaterials on interfaces and in continuous phase. Emulgel composed of multiphases allow a vast range of composition options and superior printability. The excellent attributes initiate NC with spatial control over geometrics and functions through 3D printing of graphene oxide/phase-change materials emulgel, for instance. This versatile approach provides the means for architecting NCs with nanomaterial continuous phase whose performance does not constrain the vast array of available nanomaterials and allows for arbitrary hybridization and patterns.

Hydrogel can provide a favorable moisture environment for skin wound healing. In this study, a novel in-situ crosslinked injectable hydrogel was prepared using the water-soluble amidated pectin (AP) and oxidized chitosan (OC) through Schiff-base reaction without any chemical crosslinker. The influence of AP content on the properties of the hydrogel was systemically investigated. It showed that gelation time, pore structure, swelling capability and degradability of the hydrogel can be tuned by varying the content of amine and aldehyde groups from AP and OC. All the porous hydrogels with various AP contents (65%, 70%, and 80%) presented desirable gelation time, swelling property, high hemocompatibility and biocompatibility. Particularly, AP-OC-65 hydrogel presented superior swelling capability and better hemo- and bio-compatibility, owing to more residual amine sites in the hydrogel. Therefore, the injectable AP-OC-65 hydrogel has a greater potential for application to wound dressing or skin substitute., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A robust hybrid ion gel is fabricated utilizing the combined strategies of double-network (DN), composite, and high-functionality cross-linkers. The charged poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) constructs the DN skeleton, with graphene oxide (GO) and N , N '-methylenebisacrylamide (MBA) being the cross-linkers for the first and second networks, respectively. The ionic liquid, either 1-ethyl-3-methylimidazolium dicyanamide ([EMIm][DCA]) or 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF 4 ]), is locked in the network to offer the high conductivity. Compared to the DN PAMPS ion gel without nanoparticles and the hybrid DN ion gel with unconnected silica nanoparticles, the present ion gel exhibits a significantly higher tensile strength (3.2 ± 0.1 MPa) and an excellent compressive strength (26 ± 1 MPa). The [EMIm][DCA] ion gel has a high conductivity close to that of its neat ionic liquids. The conductivity of the gel is sensitive to deformation and temperature, which leads to potential applications in sensing body movements, pulse, and temperature change.

Agarose is a prominent marine polysaccharide representing reversible thermogelling behavior, outstanding mechanical properties, high bioactivity, and switchable chemical reactivity for functionalization. As a result, agarose has received particular attention in the fabrication of advanced delivery systems as sophisticated carriers for therapeutic agents. The ever-growing use of agarose-based biomaterials for drug delivery systems resulted in rapid growth in the number of related publications, however still, a long way should be paved to achieve FDA approval for most of the proposed products. This review aims at a classification of agarose-based biomaterials and their derivatives applicable for controlled/targeted drug delivery purposes. Moreover, it attempts to deal with opportunities and challenges associated with the future developments ahead of agarose-based biomaterials in the realm of advanced drug delivery. Undoubtedly, this class of biomaterials needs further advancement, and a lot of critical questions have yet to be answered., Competing Interests: Declaration of Competing Interest None, (Copyright © 2020. Published by Elsevier B.V.)

Removal of commonly used pesticide, atrazine was examined by employing chitin based nanohydrogel. Chitin-cl-poly (acrylamide-co-itaconic acid) nanohydrogel was synthesized by microwave method. Dissolution of chitin was done by freezing thawing method in NaOH/urea solution. The morphology and functional characteristics were confirmed by FTIR, XRD, SEM, TGA, TEM, and EDX techniques. Maximum swelling capacity, isotherm study, kinetics, adsorption and desorption of atrazine pesticide were evaluated in this study. Maximum adsorption capacity of designed nanohydrogel was found to be 204.08 mg/g. Langmuir and pseudo- second order models were determined to be applicable for explaining the undertaken adsorption process. Neutral pH was found to be favorable for maximum adsorption. In addition, results have specified the pH responsive nature of nanohydrogel for controlled release of atrazine., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Developing a novel scaffold carrier with a sustained and controllable release profile of drug is essential to promote the effective transdermal delivery for acyclovir (ACY). In this work, electrospun polyacrylonitrile nanofibers (PAN NFs) was chemically modified with oxidized chitosan (OC). The modified fibrous scaffold was further loaded with the ACY for drug released investigation. FT-IR and NMR results revealed that the conversion of the functional group for each step has successfully occurred on the surface of the fibers. Through the in-vitro drug release and kinetic study, it demonstrated that ACY could be sustainably and controlled released from the OC modified scaffold following the Korsmeyer-Peppas model with a Fickian diffusion mechanism. The human adipose-derived stem cells and the blood combability evaluation confirmed the obtained scaffold possessed excellent cell biocompatibility and hemocompatibility. It could be concluded that the resultant OC modified scaffold based on electrospun PAN NFs opened a new potential option for the topical/transdermal drug delivery of ACY., (Copyright © 2020. Published by Elsevier B.V.)

Reconstruction and functional rehabilitation of the long urethra in males is one of the difficult tasks in urological treatment. Although many kinds of tissue-engineered urethra scaffold grafts have been successfully used in animals and even clinical research of urethra reconstruction, they all have the disadvantages of slow vascularization in scaffolds, which may lead to complications such as stricture and blockage of the urethra. Here, an amphiphilic polyurethane tubular nanofiber scaffold with a hierarchical structure was designed as a urethral scaffold. The scaffold can regulate the phenotypic expression of epithelial cells (ECs) and smooth muscle cells (SMCs) in vitro and in vivo. Upon transplantation into the Beagle puppy's defective urethral site, the engineered PU-ran tubular scaffold graft, rich in seeded cell-matrix bio-interfaces, could induce local neo-vascularization in a controlled way, which facilitated lumen epithelialization and functional rehabilitation. This is favorable for urethral tissue-oriented reconstruction. These findings suggest the pivotal role of nano-topographical and biochemical features in the vascularized biomimetic scaffold design for efficacious urethral reconstruction.

Reconstitution of urethral defects through a tissue-engineered autologous urethra is an exciting area of clinical urology research. Despite rapid advances in this field, a tissue-engineered urethra is still inaccessible to clinical applications because of the poor vascularization of the current scaffold materials, especially for the reconstruction of complex urethral defects. In this study, we report the preparation of multifaceted bio-interfacing tissue-engineered autologous scaffolds based on alternating block polyurethane (abbreviated as PU-alt), a kind of tubular scaffold with a hierarchical nanofiber architecture, flexible mechanical properties and a hydrophilic PEGylation interface capable of promoting adhesion, oriented elongation, and proliferation of New Zealand rabbit autologous urethral epithelial cells (ECs) and smooth muscle cells (SMCs) simultaneously, and also upregulating the expression of keratin (AE1/AE3) in ECs and contractile protein (α-SMA) in SMCs as well as the subsequent synthesis of elastin. Three months in vivo scaffold substitution of rabbit urethras displayed that the engineered autologous PU-alt scaffold grafts, with a coating rich in seed cell-matrix, could induce local neo-vascularization, facilitating oriented SMC remodeling and lumen epithelialization as well as patency. Our findings indicate a central role of the synergistic interplay of seed cell-matrix bio-interface and nano-topographic cues in the vascularized urethral reconstruction.

The linear and nonlinear rheology of associative colloidal polymer assemblies with metallo-supramolecular interactions is herein studied. Polystyrene- b -poly( tert -butylacrylate) with a terpyridine ligand at the end of the acrylate block is self-assembled into micelles in ethanol, a selective solvent for the latter block, and supramolecularly connected by complexation to divalent metal ions. The dependence of the system elasticity on polymer concentration can be semi-quantitatively understood by a geometrical packing model. For strongly associated (Ni 2+ , Fe 2+ ) and sufficiently concentrated systems (15 w/v%), any given ligand end-group has a virtually 100% probability of being located in an overlapping hairy region between two micelles. By assuming a 50% probability of intermicellar crosslinks being formed, an excellent prediction of the plateau modulus was achieved and compared with the experimental results. For strongly associated but somewhat more dilute systems (12 w/v%) that still have significant overlap between hairy regions, the experimental modulus was lower than the predicted value, as the effective number of crosslinkers was further reduced along with possible density heterogeneities. The reversible destruction of the network by shear forces can be observed from the strain dependence of the storage and loss moduli. The storage moduli of the Ni 2+ and Zn 2+ systems at a lower concentration (12 w/v%) showed a rarely observed feature (i.e., a peak at the transition from linear to nonlinear regime). This peak disappeared at a higher concentration (15 w/v%). This behavior can be rationalized based on concentration-dependent network stretchability.

A hierarchical composite based on the modified reduced graphene oxide with platinum-nickel decorated polyaniline nano-spheres (rGO/PANI@PtNi) was facilely prepared via microwave-assisted self-reduction for an application in nonenzymatic hydrogen peroxide (H 2 O 2 ) detection. Compared to the pristine rGO, the composite exhibited a much tougher surface due to the stacking of conductive PANI nano-spheres on rGO sheets, leading to good dispersion of PtNi nanoparticles and a large active area. Furthermore, the multi-valance Ni 2+/3+ in the PtNi particles effectively promoted the catalytic property of Pt sites and facilitated a superior electrochemical performance of PtNi alloy than that of neat Pt. Owing to the synergistic effect of the improved electrical conductivity and the promoted electrocatalytical property, the modified glassy carbon electrode (GCE) with rGO/PANI@PtNi nanocomposite displayed an outstanding electrochemical sensitivity towards H 2 O 2 with a fast response time (<2 s), a wide linear range (0.1-126.4 mM), a low detection limit (0.5 µM), as well as a long-life stability for one week without obvious degradation. This novel strategy opens a novel and promising approach to design high performance sensors for H 2 O 2 detection.

The introduction of optoelectronic functions into viscoelastic polymers can yield highly sophisticated soft materials for biomedical devices and autonomous robotics. However, viscoelasticity and excellent optoelectronic properties are difficult to achieve because the presence of a large number of π-conjugated moieties drastically stiffens a polymer. Here, we report a variation of additive-free viscoelastic conjugated polymers (VE-CPs) at room temperature by using an intact π-conjugated backbone and bulky, yet flexible, alkyl side chains as "internal plasticizers." Some of these polymers exhibit gel- and elastomer-like rheological behaviors without cross-linking or entanglement. Furthermore, binary blends of these VE-CPs exhibit a never-seen-before dynamic miscibility with self-restorable and mechanically induced fluorescence color changes., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Atomic force microscopy (AFM) indentation is a popular method for characterizing the micromechanical properties of soft materials such as living cells. However, the mechanical data obtained from deep indentation measurements can be difficult and problematic to interpret as a result of the complex geometry of a cell, the nonlinearity of indentation contact, and constitutive relations of heterogeneous hyperelastic soft components. Living MDA-MB-231 cells were indented by spherical probes to obtain morphological and mechanical data that were adopted to build an accurate finite element model (FEM) for a parametric study. Initially, a 2D-axisymmetric numerical model was constructed with the main purpose of understanding the effect of geometrical and mechanical properties of constitutive parts such as the cell body, nucleus, and lamellipodium. A series of FEM deformation fields were directly compared with atomic force spectroscopy in order to resolve the mechanical convolution of heterogeneous parts and quantify Young's modulus and the geometry of nuclei. Furthermore, a 3D finite element model was constructed to investigate indentation events located far from the axisymmetric geometry. In this framework, the joint FEM/AFM approach has provided a useful methodology and a comprehensive characterization of the heterogeneous structure of living cells, emphasizing the deconvolution of geometrical structure and the true elastic modulus of the cell nucleus.

For the preparation of thermoresponsive copolymers, for e.g., tissue engineering scaffolds or drug carriers, a precise control of the synthesis parameters to set the lower critical solution temperature (LCST) is required. However, the correlations between molecular parameters and LCST are partially unknown and, furthermore, LCST is defined as an exact temperature, which oversimplifies the real situation. Here, random N-isopropylacrylamide (NIPAM)/dopamine methacrylamide (DMA) copolymers were prepared under a systematical variation of molecular weight and comonomer amount and their LCST in water studied by calorimetry, turbidimetry, and rheology. Structural information was deduced from observed transitions clarifying the contributions of molecular weight, comonomer content, end-group effect or polymerization degree on LCST, which were then statistically modeled. This proved that the LCST can be predicted through molecular structure and conditions of the solutions. While the hydrophobic DMA lowers the LCST especially the onset, polymerization degree has an important but smaller influence over all the whole LCST range.

An anomalous plasticizing effect was observed in polymer/ionic liquid (IL) solutions by applying broad range of rheological techniques. Poly(ethylene oxide)(PEO)/IL solutions exhibit stronger dynamic temperature dependence than pure PEO, which is in conflict with the knowledge that lower- T g solvent increases the fractional free volume. For poly(methy methacrylate)(PMMA)/IL solutions, the subtle anomaly was detected from the fact that the effective glass transition temperature T g,eff of PMMA in IL is higher than the prediction of the self-concentration model, while in conventional polymer solutions, T g,eff follows the original Fox equation. Observations in both solutions reveal retarded segmental dynamics, consistent with a recent simulation result ( Macromolecules , 2018, 51, 5336) that polymer chains wrap the IL cations by hydrogen bonding interactions and the segmental unwrapping delays their relaxation. Start-up shear and nonlinear stress relaxation tests of polymer/IL solutions follow a universal nonlinear rheological behavior as polymer melts and solutions, indicating that the segment-cation interaction is not strong enough to influence the nonlinear chain orientation and stretch. The present work may arouse the further theoretical, experimental, and simulation interests in interpreting the effect of complex polymer-IL interaction on the dynamics of polymer/IL solutions.