SiO2@Au Core鈥揝hell Nanospheres Self-Assemble To Form Colloidal Crystals That Can Be Sintered and Surface Modified To Produce pH-Controlled Membranes
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- 作者：Patricia Anne A. Ignacio-de Leon ; Ilya Zharov
- 刊名：Langmuir
- 出版年：2013
- 出版时间：March 19, 2013
- 年：2013
- 卷：29
- 期：11
- 页码：3749-3756
- 全文大小：356K
- 年卷期：v.29,no.11(March 19, 2013)
- ISSN：1520-5827
文摘
We prepared colloidal crystals by self-assembly of gold-coated silica nanospheres, and free-standing nanoporous membranes by sintering these colloidal crystals. We modified the nanopore surface with ionizable functional groups, by forming a monolayer of l-cysteine or by surface-initiated polymerization of methacrylic acid. Diffusion experiments for the cationic dye Rhodamine B through l-cysteine-modified membranes showed a decrease in flux upon addition of an acid due to the nanopore surface becoming positively charged. Diffusion experiments for the neutral dye, ferrocenecarboxaldehyde, through the PMAA-modified membranes showed a 13-fold increase in flux upon addition of an acid resulting from the protonated polymer collapsing onto the nanopore surface leading to larger pore size. Our results demonstrate that SiO2@Au core鈥搒hell nanospheres can self-assemble into colloidal crystals and that transport through the corresponding surface-modified Au-coated colloidal membranes can be controlled by pH.