AmericanChemicalSociety.com

We made further progress in our investigation on early-stage crystallization of long-chain molecules. The system under study is polyethylene in deuterated toluene solution. We used time-resolved ultra small-angle neutron scattering, which provides unique capabilities in studying our system. The length scale of interest in this study is of micron scale, which is also accessible by optical microscopy.  However, for thin lamellae, in situ observation using optical microscopy is rather difficult.  Furthermore, it would not be possible to obtain the degree of crystallinity with optical microscopy.  The main advantage here is the quantitative measurement of the ensemble average of the thin lamellar morphology during the early stage of growth.  In addition, we made further progress in developing a protocol for data analysis.   

In the study of diffusion of a tagged particle in polymeric gels, the theoretical framework is being developed. The experimental research in systems with both thermal and quenched degrees of freedom remains quite active. The dynamics of the model network and the translational diffusion of the probe particle are studied by fluorescent correlation microscopy and nuclear magnetic resonance. We will use the observations and quantitative data generated by these experiments to rigorously test our theory again other existing theories.