Infrared Laser-Induced Photo-Thermal Phase Transition of an Aqueous Poly(N-isopropylacrylamide) Solution in the Micrometer Dimension.

The phase transition of an aqueous poly(N-isopropylacrylamide) solution (PNIPAM, wt% = 1.8—3.6%) was induced by the irradiation of a focused (ca. 1 μm) 1064-nm laser beam; this brought about the formation of a single PNIPAM microparticle. The diameter of the particle was controlled to 2—9 μm through the laser power, polymer concentration, and solution temperature. The primary origin of particle formation was the photo-thermal phase transition of the polymer solution through the local heating of water (H2O) by the laser beam. The characteristic features of the phenomena, including manipulation of the PNIPAM particle by the incident laser beam and the role of radiation force for the particle formation, are discussed.

[1]  Hiroshi Masuhara,et al.  Laser manipulation and assembling of polymer latex particles in solution , 1993 .

[2]  Hiroshi Masuhara,et al.  Optical trapping of a metal particle and a water droplet by a scanning laser beam , 1992 .

[3]  Hiroshi Masuhara,et al.  Multibeam laser manipulation and fixation of microparticles , 1992 .

[4]  N. Kitamura,et al.  Size effect on photoinduced volume change of polyacrylamide microgels containing triphenylmethane leuco cyanide , 1991 .

[5]  Hiroshi Masuhara,et al.  Laser Manipulation and Ablation of a Single Microcapsule in Water , 1991 .

[6]  Hiroshi Masuhara,et al.  Three‐dimensional optical trapping and laser ablation of a single polymer latex particle in water , 1991 .

[7]  H. Misawa,et al.  Pattern formation and flow control of fine particles by laser-scanning micromanipulation. , 1991, Optics letters.

[8]  Hiroshi Masuhara,et al.  Laser-Scanning Micromanipulation and Spatial Patterning of Fine Particles , 1991 .

[9]  Toyoichi Tanaka,et al.  Phase transition in polymer gels induced by visible light , 1990, Nature.

[10]  R. Hochstrasser,et al.  Picosecond transient coherent anti-Stokes Raman spectroscopy of Rhodamine 560 in ethanol. , 1986, Optics letters.

[11]  S. Chu,et al.  Observation of a single-beam gradient force optical trap for dielectric particles. , 1986, Optics letters.

[12]  A. Ashkin,et al.  Applications of laser radiation pressure. , 1980, Science.

[13]  A. Ashkin.  Acceleration and trapping of particles by radiation pressure , 1970 .

[14]  L. Brand,et al.  Quantitative estimation of protein binding site polarity. Fluorescence of N-arylaminonaphthalenesulfonates. , 1968, Biochemistry.

[15]  Harold A. Scheraga,et al.  A Near-Infrared Study of Hydrogen Bonding in Water and Deuterium Oxide1 , 1965 .

[16]  L. Stryer,et al.  The interaction of a naphthalene dye with apomyoglobin and apohemoglobin. A fluorescent probe of non-polar binding sites. , 1965, Journal of molecular biology.

[17]  F. Winnik.  Fluorescence studies of aqueous solutions of poly(N-isopropylacrylamide) below and above their LCST , 1990 .