基于表面波散射原理,本文研制了表面光散射法表面张力实验系统。利用标准参考物质纯水和乙醇对实验系统的可靠性进行了检验,并标定了散射角度。结果表明:新系统测量的两种物质的表面张力实验结果与标准数据的偏差为0.1 mN·m^-1,散射角度约为0.2 °。利用新的表面光散射法表面张力实验系统,对质量分数为4%~16%的PEG1000、PEG2000、PEG4000、PEG6000、PEG8000水溶液的表面张力进行了实验研究,结果表明:PEG水溶液的表面张力随着PEG质量分数的增大有减小趋势,且PEG水溶液的表面张力与PEG本身的聚合度无关;PEG4000和PEG6000水溶液具有较大的表面张力,可以作为潜在的诱导蛋白质结晶的沉淀剂。

Based on the surface light scattering theory,a new apparatus for surface tension measurement was designed.Pure ethanol and water were chosen to test the accuracy of the new apparatus and determine the scattering angle.The results showed that the maximal deviation between the experimental data and the data from NIST 8.0 is 0.1 mN·m^-1.And the scattering angle is about 0.2 °.Surface tension of aqueous solution of PEG400,PEG1000,PEG2000,PEG4000,PEG6000 and PEG8000 with mass fraction of 4%~16% were measured with new designed surface light scattering apparatus.It indicated that surface tension decreases as PEG mass fraction increases.And the surface tension of PEG solutions bears no relationship to the degree of polymerization of PEG.PEG4000 and PEG6000 solutions can be used as a potential precipitant to induce protein crystallization because of their higher surface tension.