Sun Zhigang, Sevick-Muraca Eva M
The Photon Migration Laboratories, Texas A and M University, College Station, TX 77843-3573, USA.
J Colloid Interface Sci. 2004 Feb 15;270(2):329-36. doi: 10.1016/j.jcis.2003.10.016.
Frequency domain photon migration (FDPM) technique was employed to investigate the structure factors of dense, polydisperse colloidal suspensions. The angle-integrated structure factors, [S(q)], extracted from FDPM measurements of scattering properties at volume fractions ranging from 0.05 to 0.4, were compared with the values predicted from the polydisperse hard sphere Percus-Yevick (HSPY) model, as well as decoupling approximation (DA) and local monodisperse approximation (LMA) models that incorporated independently measured particle size information. Results show that the polydisperse HSPY model is the most suitable for accounting for particle interactions which predominantly arise from volume exclusion effects. Furthermore, the influence of size polydispersity upon [S(q)] is most significant at high volume fractions. The static structure factors at small wave vector q, S(0), were also assessed from dual wavelength FDPM measurements by using the small wave number approximation as well as the local monodisperse approximation. The measured S(0) agrees well with the values predicted by the polydisperse HSPY model.
采用频域光子迁移（FDPM）技术研究了致密多分散胶体悬浮液的结构因子。从FDPM测量中提取了体积分数范围为0.05至0.4的散射特性的角度积分结构因子[S(q)]，并将其与多分散硬球Percus-Yevick（HSPY）模型以及结合了独立测量的粒径信息的解耦近似（DA）和局部单分散近似（LMA）模型预测的值进行了比较。结果表明，多分散HSPY模型最适合解释主要由体积排除效应引起的颗粒相互作用。此外，在高体积分数下，尺寸多分散性对[S(q)]的影响最为显著。还通过使用小波数近似以及局部单分散近似，从双波长FDPM测量中评估了小波矢q处的静态结构因子S(0)。测量得到的S(0)与多分散HSPY模型预测的值吻合良好。
