We investigated the effect of the hydrophobicity of the side chains of mixed-charge polymers on their interaction with cancer cell membranes. Six pH-responsive mixed-charge polymeric micelles consisting of cationic, anionic, and neutral moieties were created, with differences in hydrophobicity generated by altering the type of anionic monomer and the ratio of the hydrophobic spacer moiety. Evaluation of their affinity for cell membranes revealed that increases in the hydrophobicity and pH-responsive nature led to pH-selective toxicity, which was assumed to be caused by the disruption of cell membrane integrity.

Time-resolved FTIR was used to study the crystallization kinetics of syndiotactic polystyrene. Isothermal crystallization from the melt by cooling and from the glass by heating was used to determine the temperature (T_c) dependence of the crystallization rate (k). Based on the derived k and the crystal growth rates (G) obtained from OM and depolarized light scattering, the density of primary nucleation was readily calculated. The magnitudes of the nucleation densities in the cold-crystallized samples were ~5−6 orders higher than those of the melt-crystallized samples despite the similar k values.

Distannylated dithiazologermole and germaindacenodithiazole were copolymerized with dibrominated benzothiadiazole and di(thiazolyl)benzothiadiazole to produce four new donor-acceptor conjugated copolymers. The optical, electrochemical, and thermal properties of the copolymers were characterized. DFT calculations revealed that these thiazole-containing copolymers possessed lower HOMOs and LUMOs than those of thiophene-based congeners, in accordance with the experimental results. The intramolecular noncovalent S‒N and N‒H bond interactions and the effects of the bridging atom (C or Ge) on the HOMO and LUMO energy levels were also suggested by the DFT calculations.

Catechol-modified alginates (AlgDAs) with various catechol contents were synthesized and examined as adhesive materials. AlgDA exhibited high adhesive strength with mica and moderate adhesive strength with polymer resins, although this adhesiveness was not observed for sodium alginate. AlgDA with a relatively low catechol content exhibited relatively high adhesive strength, unlike other catechol-modified polymer adhesives. AlgDA residues were successfully removed from the used substrates by a simple water washing process. AlgDA is promising as a biobased adhesive material that contributes to a sustainable society.

Sustainable and 100% biobased plastics, polyamide 11 (PA11), derived from nonedible plants are mixed with polypropylene (PP) and a reactive compatibilizer in a twin-screw extruder. It is found that PP/PA11 bioalloys exhibited surprisingly good impact strength without losing flexural modulus only when the morphology of the PP/PA11 bioalloys was well controlled at nano-meter level, such as “nano-salami” structure. This leads to overcome a past and traditional issues in biobased plastics, resulting in applying for automobile plastic parts. This technology would contribute to realizing “carbon neutrality”.

We fabricated polymer brushes using a novel concept, which involves block copolymer segregation from the polymer region at the water interface. The resulting polymer brush is called a dynamic polymer brush because block copolymer segregation is a dynamic process that occurs at room temperature and is activated through contact with water. Dynamic polymer brushes undergo self-organization in the processes of self-assembly and self-healing (if destroyed). The concept and physical characteristics of dynamic polymer brushes are discussed in this review.

A series of amphiphilic diblock copolymers (PVA_m-b-PVPi_n: m/n = 82/6, 72/26, and 70/74) with different block lengths of hydrophilic poly(vinyl alcohol) (PVA) and hydrophobic poly(vinyl pivalate) (PVPi) blocks were prepared. PVA_m-b-PVPi_n was synthesized from poly(vinyl acetate)-b-PVPi (PVAc_m-b-PVPi_n) diblock copolymer via selectively hydrolysis. In water, PVA_m-b-PVPi_n formed spherical polymer micelles with a PVPi core and a PVA shell. The hydrodynamic radius, light scattering intensity, and aggregation number of PVA_m-b-PVPi_n increased with increasing PVPi block length. In contrast, the critical micelle concentration was reduced because of stronger hydrophobic interactions.

This focus review summarized current adhesives that are capable of macroscopic adhesion in seawater. The design strategies and performance of these adhesives were reviewed based on their bonding methods. Some future research directions and perspectives for under-seawater adhesives were discussed.

The conformational relaxation of ethylene-propylene-diene terpolymer (EPDM) chains at the interface with a model filler of quartz was examined by sum frequency generation (SFG) spectroscopy in conjunction with molecular dynamics (MD) simulations. We found that the glass transition temperature (T_g) of EPDM was higher at the interface than in the bulk. Also, the conformational relaxation beyond the T_g was significant for ethylene units, but not for propylene units. This information might be useful in controlling the local conformation and dynamics of polymer chains at the interface.