Department of Chemistry, School of Natural Sciences, Shiv Nadar University, Gautam Budh Nagar 201314, Uttar Pradesh, India.
Department of Mechanical Engineering, University of Alberta, Edmonton T6G 2G8, Canada.
J Colloid Interface Sci. 2016 Jul 15;474:41-50. doi: 10.1016/j.jcis.2016.04.007. Epub 2016 Apr 7.
Gel is an intermediate phase of solid and liquid, which exhibits properties of both, and this unique feature of gel has made it an excellent choice as a reaction medium for the nanomaterials synthesis. Herein, we report use of oil swollen surfactant gels as reaction medium and exfoliation medium, for the synthesis of metals (Au, Ag) nanoparticles and graphene, respectively. Confined growth of metals (Au and Ag) nanoparticles, has been achieved by exploring tween 80 based surfactant gel as a reaction medium. Au NPs prepared within tween 80 gel were found to be spherical with size ∼5nm, arranged in template micelles. Heating triggered the growth of Au nanoparticles and particles of various shapes including triangles, rods and pentagonal, were produced. Au and Ag containing tween 80 gels were found to be promising as catalysts for the nitrophenol reduction. Apart from separate synthesis of Au and Ag nanoparticles, bimetallic (Au-Ag) nanoparticles have also been synthesized by taking advantage of selective reducing property of tween 80. First time CTAB gel has been utilized as an exfoliation medium for the quick exfoliation of graphite into graphene sheets, eliminating the necessity of any external driving force such as sonication or heating, to reinforce exfoliation.
凝胶是固体和液体的中间相，具有两者的性质，这种独特的凝胶特性使其成为纳米材料合成的反应介质的绝佳选择。在此，我们报告了使用油膨胀表面活性剂凝胶作为反应介质和剥离介质，分别用于金属（金、银）纳米粒子和石墨烯的合成。通过探索吐温 80 基表面活性剂凝胶作为反应介质，实现了金属（金和银）纳米粒子的受限生长。在吐温 80 凝胶中制备的 Au NPs 呈球形，尺寸约为 5nm，排列在模板胶束中。加热引发了 Au 纳米颗粒的生长，生成了各种形状的颗粒，包括三角形、棒状和五边形。含有吐温 80 的 Au 和 Ag 凝胶被发现是用于硝基苯酚还原的有前途的催化剂。除了分别合成 Au 和 Ag 纳米粒子之外，还利用吐温 80 的选择性还原性质合成了双金属（Au-Ag）纳米粒子。首次利用 CTAB 凝胶作为快速剥离石墨成石墨烯片的剥离介质，消除了超声或加热等任何外部驱动力来增强剥离的必要性。
