Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACS Applied Polymer Materials  

In this study, a millimeter-thick photoresponsive polymer capable of dynamic viscoelastic modulation under blue light irradiation is reported. This star-shaped polymer has a polydimethylsiloxane (PDMS) backbone networked via photoresponsive hexaarylbiimidazole (HABI) and is referred to as PDMS–HABI. By controlling the molecular weight of the PDMS precursor, the density of HABI was tuned, thereby enabling light penetration and photoresponse in samples with thicknesses up to 2 mm. Compression tests revealed that transmittance played a more crucial role than the local elastic modulus in determining the extent of compression force reduction upon light irradiation. The optimized sample exhibited a compression force reduction to 1/28 under 430 nm light irradiation. To explore practical applications, we fabricated a tactile display capable of presenting hard and soft sensations. However, as PDMS–HABI lacked shape recovery when exposed to light, it was integrated into an elastic container to endow it with resilience. The compression properties of the container filled with PDMS–HABI were evaluated under light irradiation, and photoinduced softening reduced the compression force by nearly 50%. These results indicated the feasibility of using PDMS–HABI in tactile displays capable of presenting in-plane distributions of hardness and softness with potential applications in augmented reality/virtual reality haptic interfaces.

DOI： 10.1021/acsapm.5c04825

Web of Science

Scopus

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of Inorganic and Organometallic Polymers and Materials  

Blood-compatible polymers are widely used in biomedical applications, yet the relationships between the effect of their fundamental properties under hydrated conditions on biological properties remain poorly understood. Here, we synthesized a series of poly(2-methoxyethyl acrylate)s (PMEAs) with controlled molecular weights and dispersities. The critical entanglement molecular weight (M<inf>c</inf>) of PMEA in the dry condition revealed by rheological analysis was approximately 24 kDa, which is comparable to that of poly(methyl methacrylate). In contrast, PMEA exposed to water, i.e., under water-saturated conditions showed a M<inf>c</inf> of 36 kDa. Similar to the established understanding, DSC analysis validated the presence of three types of hydration water, i.e., non-freezing, intermediate, and free waters. However, among these, the amount of non-freezing and free waters increased markedly along with the increase in molecular weight above M<inf>c</inf>. Importantly, ELISA tests revealed the significant suppression of fibronectin denaturation by employing PMEAs with molecular weights exceeding the M<inf>c</inf>. Our findings reveal how precision polymer design especially for molecular weight or polymer chain entanglement affects hydration and biological performance, thus providing molecular insight into the design of next-generation blood-compatible materials.

DOI： 10.1007/s10904-026-04464-w

Web of Science

Scopus

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Chemical Communications  

We report the synthesis and photoresponsivity of precisely designed liquid star-shaped poly(dimethyl siloxane) (PDMS) with anthracene end groups. Owing to the efficient end-linking of the flexible PDMS arms upon the first UV irradiation (λ = 365 nm, UV<inf>365</inf>), the storage modulus (G′) increased from 4.7 Pa to 119 kPa (>25 000-fold), and the physical state became a rubbery solid. Subsequent irradiation with UV light at a shorter wavelength (λ = 254 nm, UV<inf>254</inf>) decreased G′ toward the photostationary state, and viscoelasticity modulation was achieved between the two photostationary states under solvent-free conditions.

DOI： 10.1039/d5cc04840k

Web of Science

Scopus

PubMed

Language：Japanese   Publisher：The Society of Polymer Science, Japan  

<p>Crosslinked polymers are indispensable to human society. Generally, crosslinked polymers are required to have high strength and durability, i.e., high reliability. However, even in the typical adhesive application of crosslinked polymers, it is difficult to achieve both high reliability and the social demand for pinpoint dismantling, decomposition, and recycling of joined parts therefrom. Therefore, there are strong demands from industries for a technology that enables pinpoint dismantling and decomposition of even conventionally industrialized highly reliable crosslinked polymers with easily handleable external stimuli. In this article, the effective utilization of ‘sound’ and its application for the dismantling of crosslinked polymers and bond exchange reactions are introduced.</p>

DOI： 10.1295/kobunshi.74.5_231

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