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A novel diamine monomer 3,3′-Bis(2,3,5,6-tetrafluoro-4-vinylphenoxy)biphenyl-4,4′-diamine (TFVBPA) bearing double hydrophobic cross-linkable tetrafluorostyrol side-groups has been successfully synthesized via a nucleophilic substitution reaction. A series of cross-linked highly sulfonated co-polyimide (CSPIy-TFVBPAx) membranes with ion-exchange capacity (IEC) values ranging from 2.27 to 2.44 meq. g...
Nanoparticle stabilizer type, casting solution additives, and nanoparticle processing by centrifugal or magnetic separation were varied, and specific membrane characteristics were evaluated. Specifically, membrane casting solution viscosity, cast membrane thickness, pure water flux, and internal morphology were evaluated. While the addition of the additives ethanol and polyvinylpyrrolidone to a polyethersulfone-dimethylacetamide...
This work elucidates the undisturbed interior morphology of commercial ultra-high-molecular-weight polyethylene (UHMWPE) high-performance fibers through atomic force microscopy (AFM) modulus mapping of interior surfaces exposed by a novel focused ion beam (FIB)-notched sample preparation technique. The imaging shows unequivocally the presence of epitaxial crystals in the interior of highly drawn UHMWPE...
A novel water purification membrane has been prepared by layer-by-layer (LBL) assembly of tailored, core–shell star block copolymers. The star block copolymer consists of a hydrophobic polystyrene core (PS) and a plurality of charged hydrophilic arms (poly(N,N-dimethylaminoethyl methacrylate): PDMAEMA or polymethacrylic acid: PMAA). The high density of functional groups per unit volume of the PS-PDMAEMA...
High electrical conductivity in ethylene/1-octene copolymers (EOCs) was achieved by sticking CNTs onto the gelated EOCs pellet surface and the subsequent hot pressing. The electrical conductivity (σ) was observed to be dependent on the pressing temperature and the CNT loading. Variable range hopping (VRH) mechanistic study revealed a 3-d electron transport mechanism. Both unique positive and negative...
As a popular bioplastic, poly (l-lactic acid) (PLLA) still faces some drawbacks mainly related to its low crystallization rate and heat distortion resistance. Herein, we demonstrate a facile and promising route to solve these problems by compositing PLLA with poly(d-lactide) grafted cellulose nanocrystal (CNC-g-PDLA) which can be synthesized via ring-opening polymerization of d-lactide on the CNC...
Here we aim to elucidate the self-healing mechanisms in composites with embedded solution-blown nanofibers containing separate reservoirs of epoxy resin and hardener in their cores. In tensile tests of such composite materials with the resin- and hardener-containing solution-blown nanofibers embedded in a polymer matrix, it is shown that the fibers can be ruptured by stretching, thereby releasing...
A series of stimuli-responsive reverse (RO) membranes were prepared by tethering three stimuli-responsive polymers, poly (sulfobetaine methacrylate) (PSBMA), poly (4-(2-Sulfoethyl)-1-(4-vinyl-benzyl) pyridinium betain) (PSVBP) and poly (N-isopropylacrylamide) (PNIPAM) onto the surface of a commercial thin-film (TFC) RO membrane via surface-initiated graft polymerization. The membrane surface was characterized...
The quartz crystal microbalance (QCM) was used to measure the time-dependent mechanical properties of an alkyd resin throughout the transition from its application as a liquid to the formation of a solid film. Three different regions of curing were observed, corresponding to solvent evaporation; early stage curing, where the mass increases as oxygen is incorporated into the film; and long-term curing,...
The thermoresponsive copolymers of N-isopropylacrylamide (NIPAM) with sodium styrene sulfonate (SSS) exhibit a protein-like transition behavior in aqueous medium. They undergo a coil-to-globule conformational transition without phase separation. In the present work we investigated a conformation-dependent binding of polyfunctional ligands to the protein-like NIPAM-b-SSS copolymers modelling their...
Tetrathiafulvalene molecules substituted with a carboxylic acid group (TTFCOOH) were bound as redox-active moieties into a poly(4-vinyl pyridine) (P4VP) skeleton through non-covalent interactions (hydrogen bonds). The aspect of the resulting P4VP-TTFCOOH films showed a uniform and smooth morphology. Moreover, the redox function of TTFCOOH in P4VP-TTFCOOH was demonstrated using tetrachloroauric acid,...
Polyhydroxyalkanoates (PHAs) are gaining popularity as a viable biological alternative to petroleum-derived polyolefin plastic materials, especially because their material properties can be tuned through monomer composition and configuration, an uncommon phenomena in enzymatic polymer products. Because the native function of these polymers is chemical energy storage, the metabolic synthesis routes...
Poly(l-lactic acid)-poly(ethylene glycol)-poly(l-lactic acid) (PLLA-PEG-PLLA) and poly(d-lactic acid)-poly(ethylene glycol)-poly(d-lactic acid) (PDLA-PEG-PDLA) triblock copolymers having relatively high molecular weights (Mn > 60 kDa) and different lengths of PEG midblock (2–20 kDa) and PLLA, PDLA end blocks (20–45 kDa for each block) were prepared and blended in equal mass. The competing crystallization...
Self-reinforced poly(lactic acid) (SR-PLA) nanocomposites have been developed for the first time by using electrospun PLA fibre mats as a starting material followed by hot-compaction. During hot-compaction, the temperature was set while hot-pressing time was varied from 10 to 60 s to optimize processing conditions. The resulting transparent SR-PLA nanocomposite films were characterized using differential...
Nafion membranes coated with 5.5-bilayer poly(4-styrenesulfonate) (PSS)/protonated poly(allylamine) (PAH) films show Li+/Co2+ and K+/La3+ selectivities >1000 in electrodialysis (ED). The corresponding selectivities of bare Nafion are <2. Even with adsorption of only 3 polyelectrolyte layers, Nafion membranes exhibit a Li+/Co2+ selectivity >23. However, the resistance to monovalent-ion passage...
An efficient route to obtain allyl- and propargyl-containing diols from 10-undecen-1-ol, and their polymerization with isophorone diisocyanate to produce alkene- and alkyne-functionalized polyurethanes (PUs) is described. The bio-based PUs have been further modified by thiol-ene/yne coupling of thioglycerol into unsaturation to obtain a series of PUs with enhanced hydrophilicity. All the synthesized...
Core-shell nanostructured polythiophene-multiwalled carbon nanotube nanocomposites (PT-CNTs) have been synthesised by in-situ chemical oxidative polymerization of thiophene in presence of multiwalled carbon nanotubes (MWCNT) and anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT) using ferric chloride as an oxidizing agent in chloroform solution. Nanocomposites were prepared by introducing...
In this investigation we report the preparation of a hybrid material based on graphene oxide (GO) and POSS by surface modification of graphene oxide (GO) via SI-ATRP of methacryloisobutyl POSS (MAPOSS) and synthesis of composite hydrogel based on this material. This hybrid material (GO-PMAPOSS) was duly characterized by FTIR, Raman analysis, GPC, TEM, FESEM, goniometry and TGA analyses. Compared to...
We constructed and characterized a network structure of crosslinked phenolic resins using a large-scale atomistic molecular dynamics simulation with a pseudo-reaction algorithm. The atomic configuration of the reaction products was controlled by the reaction probabilities and initial molecular structures. The crosslinked structure obtained from phenols as initial molecules agreed well with experimental...
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