title: Size tunable gold nanorods evenly distributed in the channels of mesoporous silica.
abstract: Uniformly distributed gold nanorods in mesoporous silica were synthesized in situ by performing a seed-mediated growth process in the channels of SBA-15 which functions as a hard-template to confine the diameter of gold nanorods. By changing the amount of gold precursor, gold nanorods were prepared with a fixed diameter (6-7 nm) and tunable aspect ratios from 3 to 30. Transmission electron microscope and electron tomography were utilized to visualize the gold nanorods supported on one piece of SBA-15 segment and showed a fairly uniform 3-dimensional distribution of gold nanorods within the SBA-15 channels. The longitudinal plasmon resonances of the gold nanorods/SBA-15 composites analyzed by diffuse reflectance UV-vis spectra were found to be tunable depending on the length of gold nanorods. No significant decrease in surface area and/or pore size of the composite was found after growth, indicating the growth process did not disrupt the open mesoporous structure of SBA-15. The combination of the tunable size of the nanorods and their 3-dimensional distribution within the open supporting matrix makes the gold nanorods/SBA-15 composites interesting candidates to systematically study the influence of the aspect ratio of gold nanorods on their properties and potential applications, i.e., catalyst, optical polarizer, and ultrasensitive medical imaging technique.
authors.affiliation: Department of Chemistry and Geochemistry, Colorado School of Mines, 1500 Illinois Street, Golden, Colorado 80401, USA.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Li
authors.forename: Christian
authors.initials: C
authors.lastname: Kübel
authors.forename: Vasile I
authors.initials: VI
authors.lastname: Pârvulescu
authors.forename: Ryan
authors.initials: R
authors.lastname: Richards
mesh_terms: D003460:Crystallization / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D008027:Light; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D016062:Porosity; D012542:Scattering, Radiation; D012822:Silicon Dioxide / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000379:methods*; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D006046:Gold; D012822:Silicon Dioxide