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It is one of the classic polymer physics experiments to observe the crystalline morphology of polymer by the polarizing microscope, and it is an experimental technology that polymer students must master. However, the polarizing microscope observation of polymer crystal morphology in most universities is based on the observation of polymer spherulites, which is simple but relatively boring. In this experiment, the temperature gradient heating platform is introduced on the basis of the original experiment. Students can observe not only the spherulite morphology at constant temperature, but also the oriented crystal morphology under temperature gradient. Students can set different crystallization conditions to observe the crystal morphology of polymer, and explore the crystallization process and morphology of polymer under different static temperature gradient field and dynamic temperature gradient field. The experimental design adopts the exploratory experimental teaching method to stimulate students' interest in experiment, cultivate their scientific research thinking and broaden their horizon. [ABSTRACT FROM AUTHOR]

Inspired by an ancient reducing method used in textile production, sodium hydrosulfite was used to reduce graphite oxide as an efficient reducing agent in our work. The reduced materials were characterized by x-ray photoelectron spectroscopy, thermogravimetric analysis, wide-angle x-ray scattering, Raman spectroscopy, solid state (13)C NMR spectroscopy and electrical conductivity measurements, respectively. The results showed that graphite oxide can be reduced with sodium hydrosulfite in a few minutes, with a degree of reduction comparable to those achieved with hydrazine. It provides an efficient method to reduce graphite oxide and could be used as a method to prepare novel composites.