Ryo Yoshida

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSelf-Oscillating GelRyo Yoshida, Toshikazu Takahashi, Tomohiko Yamaguchi, and Hisao IchijoView Author Information National Institute of Materials and Chemical Research, 1-1, Higashi Tsukuba, Ibaraki 305, JapanCite this: J. Am. Chem. Soc. 1996, 118, 21, 5134–5135Publication Date (Web):May 29, 1996Publication History Received24 January 1996Published online29 May 1996Published inissue 1 January 1996https://pubs.acs.org/doi/10.1021/ja9602511https://d

So far stimuli-responsive polymer gels and their application to smart materials have been widely studied; this research has contributed to progress in gel science and engineering. For their development as a novel biomimetic polymer, studies of polymers with an autonomous self-oscillating function have been carried out since the first reports in 1996. The development of novel self-oscillating polymers and gels have been successful utilizing the oscillating reaction, called the Belousov-Zhabotinsk

Temperature-responsive copolymer (or ternary copolymer) gels of N-isopropylacrylamide (IPAAm) were synthesized with hydrophobic alkyl methacrylate (RMA), hydrophilic acrylamide (AAm), N,N'-dimethylacrylamide (DMAAm), and N-acryloylpyrrolidine (APy) as comonomers. The effects of these comonomers on the phase transition temperature (LCST) and the thermosensitivity have been discussed. The LCST of poly(IPAAm) gel in phosphate buffered saline (PBS) was lowered by the introduction of hydrophobic RMA,

A novel gel which undergoes an autonomic and periodical swelling−deswelling oscillation has been prepared by the copolymerization of N-isopropylacrylamide (NIPAAm) with ruthenium tris(2,2‘-bipyridine) (Ru(bpy)3) as a catalyst for the Belousov−Zhabotinsky (BZ) reaction, which is known as an oscillating reaction accompanying a rhythmical change in the redox potential. The swelling−deswelling cycle of a miniature cubic poly(NIPAAm-co-Ru(bpy)3) gel was found to be synchronized with the chemical osci

Self-oscillation of polymer chains in an aqueous solution has been achieved. The ruthenium catalyst for the Belousov-Zhabotinsky reaction was polymerized by using N-isopropylacrylamide and dissolved into the solution containing the BZ substrates. Periodical soluble-insoluble changes of the polymer chain were spontaneously induced by the BZ reaction. The conformational oscillations of the polymer were measured as the optical transmittance changes of the solution. This is the first report that rhy

Thermosensitive co-polymers of isopropyl acrylamide (IPAAm) with butyl methacrylate (BMA) are capable of 'on-off' regulation of drug release in response to external temperature changes due to skin formation with increasing temperature. To clarify the role of the surface-modulated skin and controlled pulsatile drug release patterns, the surface shrinking process was regulated by changing the length of the methacrylate alkyl side-chain. Release of indomethacin in response to stepwise temperature c

We have developed ‘self-oscillating’ gels that undergo spontaneous cyclic swelling–deswelling changes without any on–off switching of external stimuli, as with heart muscle. The self-oscillating gels were designed by utilizing the Belousov–Zhabotinsky (BZ) reaction, an oscillating reaction, as a chemical model of the tricarboxylic acid cycle. We have systematically studied these polymer gels since they were first reported in 1996. Our studies represent innovative research, creating new concepts

A method for discriminating cloud particle types was developed using lidar backscattering copolarization and cross‐polarization channel measurements from Cloud‐Aerosol Lidar With Orthogonal Polarization (CALIOP) on board Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO). In spaceborne lidar measurements, significant multiple scattering effects discriminate between cloud water and ice difficult using the depolarization ratio ( δ ). We theoretically estimated the relation

Over about the last two decades, many kinds of stimuli-responsive polymer gels in response to the change in their surroundings such as solvent composition, temperature, pH, and supply of electric field, etc., have been developed. They have attracted much attention as intelligent (or smart, biomimetic) materials which have sensor, processor and actuator functions. Applications to actuator (artificial muscle), biosensor, drug delivery systems, purification or separation systems, etc. are extensive

As novel functional materials, we developed self-oscillating polymeric materials composed of synthetic polymers coupled with an oscillating chemical reaction, the so-called Belousov–Zhabotinsky (BZ) reaction.

Totally tubular (chemical) wave! A tubular self-oscillating gel has been designed that converts the chemical energy of the Belousov–Zhabotinsky (BZ) reaction into a mechanical swelling–deswelling of the gel (see scheme). It exhibits peristaltic motion, similar to a living worm, with propagation of the chemical wave. In the gel tube, a bubble is autonomously transported by the peristaltic pumping motion.

'On-off' regulation of drug permeation through membranes in response to external temperature change has already been achieved using thermosensitive copolymers of N-isopropyl acrylamide (IPAAm) with butyl methacrylate (BMA). Increasing temperature induced formation of a dehydrated polymeric surface skin layer that stopped drug permeation. In this study, to control 'on-off' permeability of a drug, the polymer surface shrinking process was regulated by changing the length of alkyl side chain of the