Cai Jie, Kimura Satoshi, Wada Masahisa, Kuga Shigenori
Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan.
Biomacromolecules. 2009 Jan 12;10(1):87-94. doi: 10.1021/bm800919e.
Despite considerable progress in the field of metal nanoparticles synthesis, major challenges remain in many practical applications of nanoparticles which require their immobilization on solid substrates, presenting additional difficulty in separation and processing. Here, transparent nanoporous cellulose gel obtained from aqueous alkali hydroxide-urea solution was examined as supporting medium for noble metal nanoparticles. Silver, gold, and platinum nanoparticles were synthesized in the gel by hydrothermal reduction by cellulose or by added reductant. Both methods gave nanoparticles embedded with high dispersion in cellulose gels. Supercritical CO2 drying of the metal-carrying gel gave corresponding aerogels with high transmittance, porosity, surface area, moderate thermal stability, and good mechanical strength. The cellulose and metal-cellulose gels were characterized by UV/vis spectroscopy, optical microscopy, SEM, TEM, XRD, nitrogen physisorption, TGA, and tensile testing, systematically.
尽管在金属纳米颗粒合成领域取得了显著进展，但在纳米颗粒的许多实际应用中仍存在重大挑战，这些应用需要将纳米颗粒固定在固体基质上，这在分离和加工方面带来了额外的困难。在此，研究了由氢氧化碱-尿素水溶液制得的透明纳米多孔纤维素凝胶作为贵金属纳米颗粒的支撑介质。通过纤维素或添加的还原剂进行水热还原，在凝胶中合成了银、金和铂纳米颗粒。两种方法都得到了在纤维素凝胶中高度分散的纳米颗粒。对负载金属的凝胶进行超临界CO2干燥，得到了具有高透光率、孔隙率、表面积、适度热稳定性和良好机械强度的相应气凝胶。系统地通过紫外/可见光谱、光学显微镜、扫描电子显微镜、透射电子显微镜、X射线衍射、氮物理吸附、热重分析和拉伸试验对纤维素和金属-纤维素凝胶进行了表征。
