Open AccessProbing the Microenvironment in the Confined Pores of Mesoporous Silica Nanoparticles
Author(s) -
Min Xue,
Jeffrey I. Zink
Publication year - 2014
Publication title -
the journal of physical chemistry letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.563
H-Index - 203
ISSN - 1948-7185
DOI - 10.1021/jz402760b
Subject(s) - mesoporous silica , molecule , nanoparticle , mesoporous material , materials science , rotational diffusion , nanotechnology , chemical engineering , chemical physics , chemistry , organic chemistry , engineering , catalysis
The microenvironment inside of the pores of mesoporous silica nanoparticles is probed using spectroscopic techniques. The probe molecules are sealed inside of the pores by a nanovalve system that is capable of controlling the access to the pore and ensuring the exclusive probing of the pore environment without any interference from the probe molecules on the outer surface of the particles or from the surrounding solution. Rigidochromism studies are used to evaluate the rigidity of the solvent matrix inside of the pore, and dynamic fluorescence anisotropy experiments are employed to determine the rotational diffusion freedom of the probe molecule. The data show that those probe molecules are neither completely free to move nor tightly attached to the pore wall, and their mobility is changed by altering the charge of the pore wall.