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Crystalline polymers can exhibit anomalous crystallization behaviors as restricted into nanodomains. Herein, syndiotactic polypropylene (sPP) was infiltrated into nanoporous alumina templates with different pore diameters, and their nonisothermal and isothermal crystallization kinetics were investigated. As located inside nanopores, the crystallization of sPP becomes sluggish. The crystallization...
Two Y-shaped molecules combining two dissimilar (hydrophilic and hydrophobic) units with a reactive triethoxysilane moiety were synthesized by Michael addition reaction of (aminopropyl)triethoxysilane with 2-hydroxyethyl acrylate (HEA), followed by the addition of 2,2,2-trifluoroethyl acrylate (TFEA) or 1H,1H,5H-octafluoropentyl acrylate (OFPA). Hydrolytic condensations of the Y-shaped triethoxysilane...
A novel thin-film composite (TFC) forward osmosis (FO) membrane with dual-layered substrate membrane was fabricated by a double-blade casting technique using different polysulfone (PSf) concentrations for top (15 wt%) and bottom (7 wt%) substrate layers. Graphene oxide (GO) was incorporated in the substrate layer, and the dual casting approach resulted in a membrane support with a highly porous bottom...
An off-lattice dynamics Monte Carlo method is used to study the conformations of self-attractive semiflexible ring chains. The conformations depend mainly on the bending energy b and the self-attractive interaction ε of ring chains, and perfect helical structures are found in self-attractive semiflexible ring chains with the moderate attractive interaction ε. Some monomers of the semiflexible ring...
A unique oscillation shear injection molding was utilized to investigate the crystallization of poly (l-lactide) (PLLA) under the coexistence of an intense shear flow and nucleating agents. The crystalline morphology and its distribution of injection-molded PLLA were probed by wide-angle X-ray diffraction, showing that an intense shear flow promotes the crystallization significantly, whereas the nucleation...
Formulating an analytical theory, we study phase separation of a polyelectrolyte solution under poor solvent condition confined in three types of finite geometric spaces: slab, cylinder, and sphere. Divided by a Lifshitz line, bulk polyelectrolyte solution undergoes either micro- or macro-phase separation. Confinement effects for both scenarios are studied. Composition fluctuations inducing phase...
Resorcinol and formaldehyde reactions were quantitatively monitored by means of 1H and 13C NMR spectroscopy at room temperature (293 K) before heat treatment leading to formation of organic gels. We found that resorcinol substitution with formaldehyde starts with an initial surprisingly rapid step followed by a more gradual depletion of the reactants. Substituted species with both monomeric and dimeric...
Hydrogels based on thermo-responsive 2-(2-methoxyethoxy)ethyl methacrylate (pMEO2MA) are regarded as bioinert replacements of poly (N-isopropylacrylamide) in many biomedical applications. Here, we study kinetics of temperature-induced volume phase transitions (VPT) of pMEO2MA-based hydrogels of various network architecture during their water sorption and desorption processes by means of dielectric...
To increase the pseudo-capacitance and cycle stability of polyaniline (PANI), PANI was covalently attached to reduced graphene oxide (rGO) via azobenzene (Azo) units. The rGO-Azo composite was first synthesized and subsequently used for the in situ chemical polymerization of aniline to form PANI-rGO-Azo composites. The Azo units on rGO functioned as spacers to prevent the agglomeration of rGO and...
Poly(N-isopropylacrylamide-co-maleic acid) (poly(NIPAAm-co-MAc)) with an appropriate comonomer ratio was designed and synthesized as an appealing pH/thermo-responsive copolymer. In simulated physiological fluids (phosphate buffer solution (PBS) at pH = 7.4 and T = 36 °C), both carboxylic groups of MAc in copolymer (pKa1 = 3.45, pKa2 = 6.09) are in the ionized form, more hydrophilic and consequently...
A “grafting onto” approach based on two different controlled ring-opening polymerization (ROP) techniques is developed to synthesize polytyrosine-graft-poly(2-ethyl-2-oxazoline) (PTyr-g-PEtOx) copolymer conjugates of varying main backbone and pendent chain lengths. This approach consists of syntheses of propargyl functionalized polytyrosine (PTyr-O-Pr) by ROP of tyrosine N-carboxyanhydride and azide...
Graphene oxide (GO) and its derivatives with vinyl and alkyl functional groups (mGO) were synthesized and dispersed into unsaturated polyester resin (UPR) to prepare nanocomposites. Successful chemical modification of the GO sheets was confirmed by infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction. In contrast to unmodified GO, mGO was easily dispersed in UPR, even without sonication,...
Electrically conductive poly(high internal phase emulsion) (polyHIPE) nanocomposite foams based on poly(styrene-co-divinylbenzene) were prepared by incorporating polydopamine-coated carbon nanotubes (PDA-CNTs). Conductive yet amphiphobic CNTs were modified to PDA-CNTs by coating with PDA on the surface of CNTs to provide hydrophilicity. As a result, it was possible to prepare highly stable HIPEs having...
Modification of the mechanical and rheological properties of polypropylene (PP) is accomplished through the in-situ generation of polyethylene terephthalate (PET) fibrils via fiber spinning of PP/PET (95/5 wt%). This modification increases the tensile strength of PP fibers by up to 46% and elongation at break by up to seven-folds. The change in the tensile properties is governed by the draw ratio...
Poly(2-hydroxyethyl methacrylate) (PHEMA) films with gradient crosslinking density are the only hydrogel films capable of generating regular wrinkling patterns upon swelling, however, they were synthesized via a complicated two-stage photopolymerization. In an effort to develop a simple synthesis method, we found that one-step UV-curing of HEMA liquid always results in films with corrugated surface,...
Herein, a kind of multi-responsive core-crosslinked poly (thiolether ester) micelles was facilely prepared for reactive oxygen species (ROS), acid and reduction sensitive drug delivery. Firstly, a hydroxyl-rich poly (thiolether ester) (PTE) was synthesized by the thiol-ene/thiol-expoxy polymerization using ethanedithiol (EDT) and glycidylmethacrylate (GMA) as monomers. The resultant PTE was then coupled...
The core-shell polyelectrolyte complexes chitosan (CS)/hyaluronic acid (HA) nanofibers could be produced from electric field inducing phase separation during the progress of electrospinning. The morphology of core-shell nanofibers was supported using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The presence of CS on the shell of the nanofibers was also verified by...
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