The functional sugar alcohols have been widely used in pharmaceutical and food industries, and their diffusion coefficient in aqueous solution is one of the most important parameters for correlative study and application. Therefore, the experimental investigation is of practical and theoretical significance. In this paper,the diffusion coefficients of erythritol, xylitol, sorbitol, mannitol and maltitol in the aqueous solutions at 293.15 K were determined by real-time holographic intefferometer combining with CCD picture collection and digital processing technique. The experimental results show that, at the same concentration, the diffusion coefficients are inversely proportion to the molecular size of the solutes, and they vary in the order as follows: D(erythritol)y D(xylitol) ＞ D(sorbitol) ＞ D(mannitol) ＞ D(maltitol). On the basis of Gorden model, a new equation was proposed to calculate the liquid diffusion coefficients of sugar alcohols in aqueous solutions. The calculated values of the proposed equation are in good agreement with the experimental results. The results obtained in this work could provide some valuable reference for optimizing separation and processing of the function sugar alcohols.%功能糖醇在医药和食品中得到广泛应用,其在水溶液中的扩散系数是相关研究与应用中最基本和最重要的物性参数之一,因此实验测定功能糖醇在水溶液中的扩散系数具有十分重要的意义.今采用实时激光全息干涉法,结合CCD图像采集和数字处理技术,测定了293.15 K下赤藓醇、木糖醇、山梨醇、甘露醇以及麦芽糖醇在水溶液中的扩散系数.实验结果表明,相同浓度下,扩散系数与物质分子大小成反比,对于所测定的5种物质,其大小顺序为:D(赤藓醇)＞D(木糖醇)＞D(山梨醇)＞D(甘露醇)＞D(麦芽糖醇).以Gorden模型为基础,提出了糖醇类溶质在水溶液中扩散系数的关联式,计算值和实验值吻合良好.
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