Department of Organic Chemistry, Indian Institute of Science, Bangalore 560012, Karnataka.
J Phys Chem B. 2013 Jul 3;117(26):8039-46. doi: 10.1021/jp4029497. Epub 2013 Jun 21.
A new class of steroid dimers (bile acid derivatives) linked through ester functionalities were synthesized, which gelled various aromatic solvents. The organogels formed by the three dimeric ester molecules showed birefringent textures and fibrous nature by polarizing optical microscopy and scanning electron microscopy, respectively. A detailed rheological study was performed to estimate the mechanical strengths of two sets of organogels. In these systems, the storage modulus varied in the range of 0.8-3.5 × 10(4) at 1% w/v of the organogelators. The exponents of scaling of the storage modulus and yield stress of the two systems agreed well with those expected for viscoelastic soft colloidal gels with fibrillar flocs. The nanofibers in the organogel were utilized to engineer gold nanoparticles of different sizes and shapes and generate new gel-nanoparticle hybrid materials.
一类通过酯键连接的新型甾体二聚体（胆酸衍生物）被合成出来，它们可以使各种芳香族溶剂凝胶化。通过偏光显微镜和扫描电子显微镜，分别观察到由三个二聚酯分子形成的有机凝胶具有双折射纹理和纤维状性质。进行了详细的流变学研究，以估计两组有机凝胶的机械强度。在这些体系中，在 1%w/v 的有机凝胶剂下，储能模量在 0.8-3.5×10(4)范围内变化。两个体系的储能模量和屈服应力的标度指数与具有纤维状絮状物的粘弹性软胶体凝胶的预期值吻合良好。有机凝胶中的纳米纤维被用于构建不同尺寸和形状的金纳米粒子，并生成新的凝胶-纳米粒子杂化材料。
