Department of Chemistry and Biochemistry, University of California-Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095, United States.
Langmuir. 2011 May 3;27(9):5204-10. doi: 10.1021/la200021r. Epub 2011 Apr 6.
The structural evolution and rheology of dense nanoemulsion gels, which have been formed by creating strong attractions between slippery nanodroplets, are explored as a function of steady shear rate using rheological small-angle neutron scattering (rheo-SANS). For applied stresses above the yield stress of the gel, the network yields, fracturing into aggregates that break and reform as they tumble and interact in the shear flow. The average aggregate size decreases with increasing shear rate; meanwhile, droplet rearrangements within the clusters, allowed by the slippery nature of the attractive interaction, increase the local density within the aggregates. At the highest shear rates, all clusters disaggregate completely into individual droplets.
利用流变学小角中子散射(rheo-SANS)研究了通过在滑腻的纳米液滴之间产生强吸引力而形成的密集纳米乳液凝胶的结构演变和流变性能,作为稳态剪切速率的函数。对于高于凝胶屈服应力的应用应力,网络屈服,破碎成聚集体,这些聚集体在剪切流中滚动和相互作用时会断裂和重新形成。平均聚集体尺寸随剪切速率的增加而减小;同时,由于吸引力相互作用的滑腻性质,簇内的液滴重新排列增加了聚集体内的局部密度。在最高剪切速率下,所有的簇完全解聚成单个液滴。