John A. Paulson School of Engineering and Applied Sciences, Wyss Institute for Biologically Inspired Engineering, Harvard University , Cambridge, Massachusetts 02138, United States.
Langmuir. 2017 Jul 11;33(27):6869-6877. doi: 10.1021/acs.langmuir.7b01476. Epub 2017 Jun 27.
Colloidal gel foams are composed of a continuous, attractive particle network that surrounds and interconnects dispersed bubbles. Here, we investigate their stability, morphology, and elasticity as a function of foaming intensity, surfactant concentration and hydrophobicity, pH, and colloid volume fraction. Upon optimizing these parameters, highly stable colloidal gel foams are created. Within this stability region, the specific interfacial area between the continuous (colloidal gel) and dispersed (bubble) phase can be varied over 2 orders of magnitude leading to a concomitant increase in storage modulus, which scales nearly linearly with specific interfacial area. Our observations provide design guidelines for attractive-particle stabilized foams that enable the programmable assembly of architected porous materials.
胶态凝胶泡沫由连续的、有吸引力的颗粒网络组成，这些颗粒网络包围并相互连接分散的气泡。在这里，我们研究了它们的稳定性、形态和弹性作为发泡强度、表面活性剂浓度和疏水性、pH 值和胶体体积分数的函数。通过优化这些参数，我们创建了高度稳定的胶态凝胶泡沫。在这个稳定区域内，连续相（胶态凝胶）和分散相（气泡）之间的比界面面积可以变化两个数量级以上，从而导致储能模量的相应增加，储能模量几乎与比界面面积呈线性关系。我们的观察结果为有吸引力的颗粒稳定的泡沫提供了设计指南，这些泡沫能够实现结构多孔材料的可编程组装。
