水、甲醇、乙醇对含水脑磷脂液晶结构影响的X射线衍射研究

SAXS STUDY OF THE INFLUENCE OF WATER, METHANOL AND ETHANOL ON THE LIQUID-CRYS TAL STRUCTURE OF CEPHALIN

用小角X射线散射法(SAXS)对含水脑磷脂分别用水、甲醇和乙醇实验所形成的液晶体系结构进行了研究。实验结果证明:在脑磷脂-水体系中,随着水含量增加,脑磷脂和水形成的双分子层液晶体系的层间距变大;在脑磷脂-甲醇体系中,随着甲醇含量增加,它们的层间距变小。在脑磷脂-乙醇体系中,随着乙醇含量的增加,它们的层间距先由小到大,继而又由大变小,然后液晶相逐渐消失,最后变成液态。水和甲醇、乙醇相比,水有使层间距变大的趋势,醇类有使层间距变小的趋势,随着醇中碳链的增长,层间距减小的趋势增大。

This treatise introduces the results of the auther's research in using the method of SAXS (the small angle X-ray scattering) on the structure of the liquid-crystal system made from micro-hydro cephalin with water, methanol and ethanol respectively. Experiments reveal to us the following phenomena: in the cephalin-water system when the content of water increases, the repeat distance of bilayers in the liquid-crystal system of cephalin and water widens and in the cephalin-methanol and cephalin-ethanol system, when the content of alcohol increases the repeat distance narrows; according to the multiplies of hydro-carbon chain in alcohol, the repeat distance varies from wider to narrower, then vanishes gradually and at last the liquid-crystal phase changes into liquid phase. Therefore it is quite clear that water and alcohol, exert different influence on the repeat distance of liquid-crystal phase of cephalin.