通过光诱导化学气相沉积法对银纳米颗粒进行二氧化硅包覆

SiO2 coating of silver nanoparticles by photoinduced chemical vapor deposition.

作者信息

Boies Adam M, Roberts Jeffrey T, Girshick Steven L, Zhang Bin, Nakamura Toshitaka, Mochizuki Amane

机构信息

Department of Mechanical Engineering, University of Minnesota, 111 Church Street SE, Minneapolis, MN 55455, USA.

出版信息

Nanotechnology. 2009 Jul 22;20(29):295604. doi: 10.1088/0957-4484/20/29/295604. Epub 2009 Jul 1.

DOI:10.1088/0957-4484/20/29/295604

PMID:19567950

Abstract

Gas-phase silver nanoparticles were coated with silicon dioxide (SiO2) by photoinduced chemical vapor deposition (photo-CVD). Silver nanoparticles, produced by inert gas condensation, and a SiO2 precursor, tetraethylorthosilicate (TEOS), were exposed to vacuum ultraviolet (VUV) radiation at atmospheric pressure and varying temperatures. The VUV photons dissociate the TEOS precursor, initiating a chemical reaction that forms SiO2 coatings on the particle surfaces. Coating thicknesses were measured for a variety of operation parameters using tandem differential mobility analysis and transmission electron microscopy. The chemical composition of the particle coatings was analyzed using energy dispersive x-ray spectrometry and Fourier transform infrared spectroscopy. The highest purity films were produced at 300-400 degrees C with low flow rates of additional oxygen. The photo-CVD coating technique was shown to effectively coat nanoparticles and limit core particle agglomeration at concentrations up to 10(7) particles cm(-3).

摘要

通过光诱导化学气相沉积（photo-CVD）法，用二氧化硅（SiO₂）包覆气相银纳米颗粒。由惰性气体冷凝法制备的银纳米颗粒以及SiO₂前驱体正硅酸四乙酯（TEOS），在大气压和不同温度下暴露于真空紫外（VUV）辐射中。VUV光子使TEOS前驱体解离，引发化学反应，在颗粒表面形成SiO₂涂层。使用串联差分迁移率分析和透射电子显微镜，针对多种操作参数测量了涂层厚度。利用能量色散X射线光谱法和傅里叶变换红外光谱法分析了颗粒涂层的化学成分。在300 - 400摄氏度以及低流速的额外氧气条件下，制备出了纯度最高的薄膜。结果表明，photo-CVD涂层技术能够有效地包覆纳米颗粒，并在浓度高达10⁷个颗粒·厘米⁻³的情况下限制核心颗粒的团聚。