期刊
JOURNAL OF PHYSICAL CHEMISTRY B
卷 109, 期 15, 页码 7033-7039出版社
AMER CHEMICAL SOC
DOI: 10.1021/jp044894b
关键词
-
We developed a confocal Raman microspectroscopy system combined with a laser trapping technique and applied it to aqueous solutions (H2O and D2O) Of poly(N-isopropylacrylamide) (PNIPA), which is well-known as a representative thermo-responsive polymer, i.e., phase transition/separation between coiled and globular states. By introducing a near-infrared (1064 nm) laser beam into a microscope, PNIPA microparticles were produced at the focused spot of the laser beam, both in H2O and D2O. By using the present system, we succeeded in obtaining the Raman spectra of PNIPA in the coiled and globular states over a wide wavenurnber region (800-3500 cm(-1)) for the first time. For the D2O solutions (in which the photothermal effect is negligible and hence the microparticles should be produced purely by the effect of radiation pressure), some significant differences were observed in the Raman spectra for the coiled state, in the globular state, and for laser induced microparticles. By analyzing these spectra in detail, we revealed that the structure of the laser-induced microparticles was analogous to that in the globular state. We also discuss the fundamental mechanism underlying the transformation of the higher order structure of a polymer by radiation pressure.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据