Robust PEDOT:PSS Wet‐Spun Fibers for Thermoelectric Textiles

To realize thermoelectric textiles that can convert body heat to electricity, fibers with excellent mechanical and thermoelectric properties are needed. Although poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is among the most promising organic thermoelectric materials, reports that explore its use for thermoelectric fibers are all but absent. Herein, the mechanical and thermoelectric properties of wet‐spun PEDOT:PSS fibers are reported, and their use in energy‐harvesting textiles is discussed. Wet‐spinning into sulfuric acid results in water‐stable semicrystalline fibers with a Young's modulus of up to 1.9 GPa, an electrical conductivity of 830 S cm^?1, and a thermoelectric power factor of 30 μV m^?1 K^?2. Stretching beyond the yield point as well as repeated tensile deformation and bending leave the electrical properties of these fibers almost unaffected. The mechanical robustness/durability and excellent underwater stability of semicrystalline PEDOT:PSS fibers, combined with a promising thermoelectric performance, opens up their use in practical energy‐harvesting textiles, as illustrated by an embroidered thermoelectric fabric module.     

Self‐Cleaning,Thermoresponsive P(NIPAAm‐co‐AMPS) Double Network Membranes for Implanted Glucose Biosensors

A self‐cleaning membrane that periodically rids itself of attached cells to maintain glucose diffusion could extend the lifetime of implanted glucose biosensors. Herein, we evaluate the functionality of thermoresponsive double network (DN) hydrogel membranes based on poly(N‐isopropylacrylamide) (PNIPAAm) and an electrostatic co‐monomer, 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS). DN hydrogels are comprised of a tightly crosslinked, ionized first network [P(NIPAAm‐co‐AMPS)] containing variable levels of AMPS (100:0–25:75 wt% ratio of NIPAAm:AMPS) and a loosely crosslinked, interpenetrating second network [PNIPAAm]. To meet the specific requirements of a subcutaneously implanted glucose biosensor, the volume phase transition temperature is tuned and essential properties, such as glucose diffusion kinetics, thermosensitivity, and cytocompatibility are evaluated. In addition, the self‐cleaning functionality is demonstrated through thermally driven cell detachment from the membranes in vitro.

     

Self‐assembled amphiphilic poly‐N‐vinylpyrrolidone nanoparticles as carriers for hydrophobic drugs: Stability aspects

Nanoparticles can experience numerous impacts during storage or after intravenous administration resulting in disassembly and/or drug leakage and affecting their efficiency as drug delivery systems. In this study, this crucial issue was addressed by investigating the stability of amphiphilic poly‐N‐vinylpyrrolidone derivative nanocarriers in blood serum, against destabilizing agents and during long‐term storage. All amphiphilic poly‐N‐vinylpyrrolidone derivative nanoparticles prepared in this study were found to possess sizes less than 150 nm, narrow size distribution, spherical morphology, and a slightly negative surface charge. These nanoparticles could efficiently entrap hydrophobic substances (pyrene and curcumin) while retaining excellent compatibility with red blood cells. Moreover, our studies demonstrate the stability of the nanoparticles during long‐term storage and upon dilution with body liquids enhancing their potential as stable in vivo carriers, which is critically important for intravenous drug delivery applications. All properties were found to strongly depend on the ratio between the hydrophobic and the hydrophilic moiety of the polymers under study. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45637.     

Microwave‐Assisted Reversible Coordination‐Mediated Polymerization for Self‐Healing Hybrid Materials: RGO@PDA Simultaneous as Catalyst and Nanocomposites in One‐Pot

In this article, polydopamine (PDA) is efficiently adhered on the surface of graphene oxide (GO) by mussel‐inspired chemistry. The obtained reduced GO/PDA (RGO@PDA) nanocomposites are used for catalyzing reversible coordination‐mediated polymerization under microwave radiation. Well‐defined and iodine‐terminated polyacrylonitrile‐co‐poly(n‐butyl acrylate) (PAN‐co‐PnBA) is successfully fabricated by using RGO@PDA nanocomposites as catalysts. Importantly, green and novel strategy of PAN‐co‐PnBA‐type self‐healing nanocomposite materials is further fabricated with RGO@PDA as additive after polymerization as catalyst in one‐pot. As a reinforcement agent, RGO@PDA can also improve the mechanical and self‐healing properties of hybrid materials, which opens up a novel and green methodology for the preparation of self‐healing hybrid materials.     

Two‐Phase Hydroformylation of Higher Olefins Using Randomly Methylated α‐Cyclodextrin as Mass Transfer Promoter: A Smart Solution for Preserving the Intrinsic Properties of the Rhodium/Trisulfonated Triphenylphosphine Catalytic System

The two‐phase hydroformylation of higher olefins with the rhodium/trisulfonated triphenylphosphine catalytic system in the presence of various chemically modified α‐cyclodextrins has been investigated. These cyclodextrins allowed us to increase greatly the reaction rate and the chemoselectivity of the reaction but, contrary to what has been observed previously with the chemically modified β‐cyclodextrins, the linear to branched aldehydes ratio was not affected by the presence of α‐cyclodextrin derivatives. Indeed, the latter was found to be similar to that obtained without any mass transfer promoter, suggesting that the catalytic species are stable in the presence of α‐cyclodextrin derivatives.