Spectroscopic studies of confined molecules under shear. Soga, Iwao; Dhinojwala, Ali; Cho, Yoon-Kyoung; Granick, Steve. Dep. Materials Sci. and Eng., Univ. Illinois, Urbana, IL, USA. Mater. Res. Soc. Symp. Proc. (1997), 464(Dynamics in Small Confining Systems III), 89-97. CODEN: MRSPDH ISSN: 0272-9172. Journal written in English. CAN 127:142504 AN 1997:378674 CAPLUS

The authors introduce 2 new techniques with the sensitivity to measure spectroscopic properties of confined mols. under shear. One concerns rheo-optics of fluids in micro-sized gaps. The exptl. approach consists in applying periodic shear motion to fluid films confined between parallel plates sepd. by controllable film thickness from 0.1 to 100 mm. A key aspect is the concurrent ability to perform spectroscopic expts. (IR or dielec. spectroscopy, or x-ray or neutron spectroscopy) of these fluids during flow. The 2nd technique consists in flow field expts. of polymer adsorption and orientation. The exptl. approach is to produce 1-directional shear, at rates up to 104 sec-1, past adsorbed polymer layers of thickness <0.01 mm. The selective augmentation of vibrational modes oriented preferentially along the chain backbone is then used to prove chain orientation in the direction of flow in a laminar flow field.