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Surface modification of carbon materials with polymers is useful for engineering surface properties and adding functionality to carbon materials. This review article describes processes for coating carbon materials with polybenzimidazoles and their applications.
Double-cyclopolymerization of trifunctional heptaisobutyl-substituted corner-opening typed cage silsesquioxane produced soluble polymers by applying the precision polymerization technique to avoid cross-linking reaction during the polymerization. Cast films of the resulting double cyclic polymers showed excellent optical transparent and good thermal properties as well as stable hydrophobic surfaces.
A novel substituted phenylacetylene with a pendant betulin derivative group was designed and synthesized successfully, The obtained monomer was further polymerized in an achiral catalytic system, and polymer exhibited a strong Cotton effect at the main-chain absorption regions in the circular dichroism spectra. The helical porous material polyphenylacetylene grafted onto the natural product lupane triterpene as a side group exhibits a set of valuable properties with excellent thermal stability, solubility and membrane-forming ability.
We performed cationic ring-opening polycondensation of a galactose-based cyclic sulfite monomer to give (1 → 2)-galactan. Treatment of the cyclic sulfite with 10-(+)-camphorsulfonic acid (CSA) in the presence of water initiated ring-opening polycondensation to give benzylated (1 → 2)-galactan. The MALDI-TOF mass spectrum of the obtained polymer showed a simple pattern with even intervals, indicating the formation of benzylated (1 → 2)-galactan with OH termini. When we used 4-penten-1-ol as the alcohol initiator for cationic polycondensation, we obtained a pentenoyl group-terminated polymer and/or cyclic oligosaccharides. The mechanism for the polycondensation reaction was determine through systematic investigations of the polymerization and DOSY spectral measurements of the polymer. The present method may be useful with graft polymerizations designed to give oligogalactan-containing glycosides in one pot.
The emulsion stabilization conditions suitable for nanocellulose-coated microparticle syntheses was investigated by changing the lengths of nanocelluloses. The optimal nanocellulose concentration for stabilizing the emulsion was found to vary with the nanocellulose length, and longer nanocelluloses efficiently stabilized the emulsion at lower concentrations due to the higher viscosity. The emulsions stabilized by shorter nanocelluloses were found to be more suitable for the preparation of fine microparticles because the nanocelluloses effectively covered the surfaces of oil droplets in the emulsions, precluding coalescence.
During bulk polymerization, the relative concentration of monomer and polymer changes. When the monomer is liquid and the obtained polymer is a glassy solid, vitrification occurs at some point of the reaction. Herein, we investigate the bulk polymerization of methyl methacrylate, ethyl methacrylate, and butyl methacrylate. We show that, at the vicinity of vitrification, the reaction solution becomes heterogeneous, which results in an apparent phase separation. We discuss polymerization-induced vitrification in conjunction with reaction acceleration (the Trommsdorff effect) and subsequent deceleration (the glass effect).
The interdetector delay volumes (IDV) for multiangle light scattering (MALS) and differential refractometer detectors are essential instrumental parameters affecting reliability and accuracy. However, a reliable and accurate determination method has not yet been established. The paper proposes a method for determining the IDV value. An SEC-MALS setup with the correct IDV value provides more accurate estimates of not only the weight average molar mass and z-average mean-square radius of gyration but also the number average molar mass and differential weight distribution function for polymer samples having narrow and broad molar mass distributions.
The optimum processing conditions for PEDOT:PSS and PEDOT:PSS/Tween 80 cast films were determined in terms of sheet resistivity and film quality. The sheet resistivity of the films was found to decrease by up 85% following annealing at 140 °C. Further analysis showed this reduction to be created by both moisture removal and structural rearrangement. The presence of Tween 80 significantly altered the thermal stability of PEDOT:PSS films highlighting the importance of reoptimizing processing conditions for each additive used.
The maintenance of stem cells multipotency and control of the differentiation direction are important for these applications in tissue engineering. We explored whether the multipotency of adipose derived stem cells (AdSCs) is maintained when they are removed from injectable polymer (IP) hydrogels with various degrees of cross-linking and induced to differentiate into osteoblasts and adipocytes. We confirmed that AdSCs cultured in IP hydrogels maintained an undifferentiated state. However, when cultured in an IP hydrogel, their multipotency was reduced.
PLLA exhibits excellent biocompatibility and biodegradability, but its poor hydrophilicity causes less cell adhesion. To address this issue, the bioactive peptide scaffold was synthesized by PLLA fiber substrate modified with an IKVAV peptide and following heat treatment at 60 °C for regulation of cell adhesive. This scaffold has the potential to serve as an in vitro model for investigating the effect of the ECM on glioblastoma multiforme cells and tumor metastasis in white matter tracts.
The new strategy of two different AS-ODNs (targeting K-ras and YB-1) being delivered simultaneously to the same target cancer cell was investigated using the quantized complex made from AS-ODNs and short β-glucan (schizophyllan (SPG)). We used the quantized complex properties to prepare both end complexes with AS-ODNs on both ends. Both end complexes silenced two target genes and showed high inhibition of cancer cell growth. The results indicate that both end complexes can deliver two antisense sequences at the same time and show a synergistic effect.
Polytetrafluoroethylene (PTFE) has widely been used in essential daily items and biomedical materials. The application range of PTFE should be greatly expanded if it can be flexibly functionalized. However, the functionalization method is still limited. In this study, peptides with affinity to PTFE were identified through affinity-based selection from a phage-displayed peptide library. The peptides had potential as a molecular glue to immobilize functional proteins and biomolecular assemblies, i.e., phages, onto PTFE films.
