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By employing molecular dynamics simulations, we explored different size-dependent dynamics of NPs in semiflexible linear and ring polymer nanocomposites. Large NPs diffuse faster slightly in flexible ring polymer nanocomposites than in flexible linear polymer ones. However, the motions of large NPs in semiflexible ring polymer nanocomposites with large bending energies are very slow and NPs exhibit...
Defect-free mixed-matrix membranes (MMMs) based on triptycene-containing polyimide and zeolite imidazole framework (ZIF-90) were prepared in systematically varied compositions using priming and solution-casting method for gas separation. Microstructure analyses confirm that hierarchical triptycene units effectively assist in the nanoparticle dispersion and prevent aggregation, which, in conjunction...
The stereoselective polymerization of β-myrcene and β-ocimene and their binary copolymerization with styrene promoted by titanium complexes dichloro{1,4-dithiabutanediyl-2,2′-bis(4,6-di-tert-butyl-phenyl)}titanium (1), dichloro{1,4-dithiabutanediyl-2,2′-bis[4,6-bis(2-phenyl-2-propyl)phenoxy]}titanium (2) and Ti(η5-C5H5)-(η2-MBMP)Cl (3) (MBMP = 2,2'methylenebis(6-tert-butyl-4-methylphenoxo)) activated...
A highly robust and flame retardant borate-crosslinked poly (vinyl alcohol)/montmorillonite aerogel is fabricated through a novel melt-crosslink method. In this way, the PVA/MMT hydrogel was prepared by immersing the frozen PVA/MMT sol into a borax solution, inducing crosslinking between diols of PVA and borate exactly during the ice melt. As a result, rearrangement of the polymer chains and subsequent...
Self-healing of mechanical damages was triggered in polymeric multilayer films of polyethylenimine/polyacrylic acid (PEI/PAA) by exposure to high humidity conditions such as immersion in deionized (DI) water. In situ wet nanoindentation was carried out to demonstrate the swelling behavior of thin films in high humidity. Once immersed in DI water, the film became softer, where roughness, modulus and...
Pharmaceutically relevant cationic linear poly(2-aminoethyl-methacrylate)s were synthesized by reversible addition-fragmentation chain transfer polymerization resulting in a homologous series of the homopolymers in a wide range of molar masses (10,000<M<130,000gmol−1) and relatively narrow dispersities (Ð:1.3±0.4). The polymers were studied in 0.2MNaCl and 0.2MNaOH in water, applying combined...
A series of deuterated tri-block copolymers with the general structure d8-PMMA-POEGMA-d8-PMMA, with variation in d8-PMMA chain length, were synthesized using sequential controlled radical polymerization (ATRP). Solid polymer electrolytes (SPEs) were produced by blending tri-block copolymers and lithium bis(trifluoro methylsulfonate) (LiTFSI). Small-angle neutron scattering (SANS) was used to study...
Polyethylene oxide (PEO)-containing multi-block copolymers are good candidates for CO2 membrane separations because of their strong affinity for CO2 but PEO crystallization and weak mechanical properties are two limitations to be overcome at high PEO content. In this work, PEO block incorporation within new linear multi-block copolymers avoided PEO crystallization. The copolymers consisted in Jeffamine...
A triblock copolymer (BCP) of the PS-b-PB-b-PS (SBS) type [PS: polystyrene, PB: polybutadiene] with cylindrical morphology containing pristine or PS-functionalised multi-walled carbon nanotubes (MWCNTs) was exposed to steady shear and large amplitude oscillatory shear (LAOS). Axis symmetric shear was applied in a rheometer for the orientation of the BCP cylinders and the alignment of MWCNTs within...
Novel one-handed helical copoly(phenylacetylene)s bearing a small amount of 3-(triethoxysilyl)propyl residues (CPAs 1–4) were synthesized, and efficiently chemically immobilized onto silica gel by the intermolecular polycondensation of the triethoxysilyl groups. Their chiral recognition abilities were evaluated as immobilized-type chiral stationary phases (CSPs) for high performance liquid chromatography...
Polymer nanocomposites with polymer grafted nanoparticles (NPs) are of great interest since they have improved properties relative to their unfilled analogs. While it is well-appreciated that nanocomposite flow behavior is critically affected by filler dispersion, the roles of the matrix and the polymeric grafts remain unexplored. We perform linear oscillatory rheology on composites of polystyrene-grafted...
In this feature article, we first make some simple reviews about the most popular theories for glass transition: 1) Free volume theory, 2) Entropy theory, 3) Götze’s Mode coupling theory, and 4) Caging and Jamming theory. We address the issue of existing studies of glass transformations. Then, we review some special colloidal/polymer model systems which can give a repulsive potential together with...
A novel two-layer reinforced carbon fiber (CF), i.e., Ag nanoparticles (Ag NPs)/graphene oxide (GO) reinforced CF (named as CF/Ag/GO) was prepared by an electrochemical deposition and electrophoretic deposition (EPD) consequently. The modified fiber showed an increased interfacial shear strength (IFSS) and tensile strength. Transmission electron microscopy (TEM), scanning electron microscopy (SEM),...
Impact mitigation in layered polymeric structures is studied to quantify the importance of impact impedance mismatch and energy dissipation modes on the overall transmission of a pressure wave. Internal reflection within the laminate structure is enhanced by optimizing the impedance between the laminate layers creating a virtual echo chamber for the impact wave. The high internal reflection potential...
Naturally occurring osmolytes are small organic compounds that affect the functioning of the macromolecule and ever-present in the living systems. Trimethylamine N-oxide (TMAO), betaine and sarcosine are among the family of methylamines which are a class of osmolytes that may lead to the alteration in the transition behaviour of thermo-responsive polymers (TRPs). In this context, we have extended...
A series of thermally reversible gels made from a solution of bio-based, biodegradable poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] (PHBHx) in dimethylformamide (DMF) were analyzed using wide angle X-ray diffraction (WAXD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). WAXD results demonstrate the existence of crystalline PHBHx in the polymer gel...
Diethyl carbonate was reacted with phenol or 1,6-hexanediol with 5 mol% dilithium tetra-tert-butylzincate (TBZL) as a catalyst at 25 or 70 °C. The exchange reaction with phenol did not occur under these conditions, while that with 1,6-hexanediol did. Thus, polycondensation of diphenyl carbonate with 1,6-hexanediol was investigated. As expected, poly (hexamethylene carbonate) was obtained without removal...
In this work, the fundamental issue of dispersing carbon nanotubes (CNTs) within a polymer matrix is addressed by studying a non-solvent induced liquid-solid phase separation process in polyacrylonitrile/CNT composite systems. To visualize the effect of phase separation, hybrid polymer/CNT buckypapers were formed through filtration. The hybrid film morphology gradually changes from a CNT-rich to a...
We study the inclusion complex formation of cyclodextrins and a single polymer chain by a grand canonical Monte Carlo simulation and by a statistical-mechanical theory. The filling ratio of the polymer chain by threaded cyclodextrins is calculated and shows good agreement with reported experimental results. The adsorption isotherm of the filling ratio is also derived by the statistical-mechanical...
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