Volume 48 Issue 5, May 2016

Epigenetics control carrier (EpC carrier) has been designed as a unique tool to control histone acetylation by simultaneous transfection of histone acetyltransferase gene and delivery of a histone deacetylase inhibitor.

We have developed a next-generation, temporary fixing agent that can be easily peeled off in film form after hot water immersion without using organic solvents. Peel-off property after hot water immersion was achieved by controlling the Tg of the cured agent, which induced to accumulate internal stress in curing and to relax the stress in hot water immersion. Such fixing agents are becoming the de facto standard for use in the processing of capacitive touch sensors on cover glasses, for example, on smartphones and tablet PCs.

This review article describes the current state-of-the-art research on organic photorefractive polymer composites. A historical background on photorefractive materials is first introduced and is followed by a discussion on the opto-physical aspects and the mechanism of photorefractivity. The molecular design of photorefractive polymers and organic compounds is discussed, followed by a discussion on optical applications of the photorefractive polymers.

In this review, we highlight recent advances in polymeric hybrid nanocarriers for photothermal treatment of cancer. These polymeric hybrid nanocarriers can store and deliver NIR-absorbing agents to cancer cells and tumor sites, exhibiting significant cytotoxic effects upon treatment under external light irradiation. Possible challenges and future prospects in this field are also emphasized.

We report a controlled chain-growth polymerization of methyl 3-octylaminobenzoate having a bithiophene chromophore at the 5-position of the benzene ring with the improved polymerization activity, which gives poly(N-octyl-m-benzamide)s with the better solubility. The introduction of a terthiophene chromophore at the propagating end is also described. From spectroscopic data and theoretical investigations, it was found that neighboring bithiophene chromophores have the π–π interaction and the excited energy can migrate along the polymer chain.

Three-arm and 6-arm poly(methyl acrylate)s (PMAs) were synthesized via atom transfer radical polymerization (ATRP) with 1,3,5-tris(bromomethyl)-2,4,6-trimethylbenzene and hexakis(bromomethyl)benzene as the initiators, CuBr as the catalyst and tris [2-(dimethylamino) ethyl] amine (Me₆TREN) as the ligand. The effect of the molar ratio of CuBr and Me₆TREN to Br of the initiator on the arm number was investigated. Hydrolysis of the products was conducted to convert the PMAs to poly(acrylic acid)s (PAAs). The solubility to water and thermal decomposition curves of 3-arm and 6-arm PAAs corresponded well to those of PAA.

The cloud point was determined in aqueous poly(N,N-diethylacrylamide) (PDEA) solutions. It was found that the cloud-point curve of each PDEA sample has a critical point and each PDEA solution exhibits phase separation into two liquid phases when the temperature is increased above its cloud point, which has not been previously observed for aqueous poly(N-isopropylacrylamide) (PNIPA) solutions. Therefore, the aqueous PDEA solutions exhibit typical phase behavior of lower critical solution temperature type, which is substantially different from that observed for PNIPA.

A polymer cross-linking system undergoes a phase transition from liquid to solid at a critical point, which is called the sol-gel transition. We independently tuned the intrinsic parameters governing the sol-gel transition, that is, the connectivity and polymer concentration, using a model gel system (tetra-polyethylene glycol gel), and examined the model predictions. The lattice-based percolation model can be applied only for systems prepared around the overlapping concentration. In the case far below the overlapping concentration, the aggregation model well reproduced the transition behavior.

Nanostructured composite electrolyte films consisting of a cross-linked lyotropic liquid crystal monomer and varying amounts of an organic carbonate liquid electrolyte and a Li salt were systematically prepared and characterized for their ionic conductivity and ability to function as the separator membrane in a Li-metal/fluorinated carbon test cell. Films with a well-defined bicontinuous cubic phase were sufficiently strong to act as an ion-conductive separator and displayed stable open-circuit potentials, whereas the majority of the mixed-phase films gave shorted cells.

Silicon- and carbon-bridged polythiophenes, dithienosilole (DTS) and cyclopentadithiophene (DTC) homopolymers with 2-ethylhexyl or n-octyl substituents on the bridging atom, were synthesized and their optical and electrochemical properties were investigated. OFET devices containing the present polymer films as the active layers were fabricated to investigate their carrier transport properties. The device based on a DTS polymer with n-octyl substituents showed much higher carrier mobility than that of the DTC polymer with the same substituents.

Light scattering and viscosity measurements were carried out for thermally renatured xanthan samples with various molar masses and molar mass distributions. The increases in the molar mass, radius of gyration, and intrinsic viscosity of a xanthan sample with high molar mass and wide molar mass distribution upon renaturation were smaller than in xanthan samples with lower molar masses and narrower molar mass distributions. This behavior could be explained by the increase in “intra-dimer-renaturation” caused by the slower diffusion of xanthan with higher molar mass.

The molecular weight of spider proteins contained in the major ampullate glands of spiders collected during different periods. The standard deviation is also indicated. A peak for molecular weight is observed in mid-autumn, which corresponds to the mating season.