Please use this identifier to cite or link to this item:
Title: Well-Defined Silica-Polymer Core-Shell Hybrids and Polymer Hollow Structures: Synthesis, Characterization and Application
Keywords: silica-polymer, core-shell, hollow structure, sol-gel, precipitation polymerization
Issue Date: 4-Aug-2011
Citation: LI GUOLIANG (2011-08-04). Well-Defined Silica-Polymer Core-Shell Hybrids and Polymer Hollow Structures: Synthesis, Characterization and Application. ScholarBank@NUS Repository.
Abstract: Well-defined inorganic/polymer core-shell hybrids and polymer hollow micro-/nanostructures are of great interest because of their diverse applications in chemistry, materials, biomedicine and nanotechnology. The aim of this work was to develop a simple and general approach to the fabrication of functional inorganic/polymer core-shell hybrids and polymer hollow nanostructures with unique morphology and decorated surface functions via a combination of traditional techniques, such as sol-gel chemistry, distillation-precipitation polymerization and living radical polymerization with the newly developed `click? chemistry. The as-prepared polymer hollow micro-/nanospheres (single shell, double shell, rattle-type and hairy hollow particles) could further been explored as drug delivery vehicles in drug delivery systems (DDSs) and nanoreactors in confined catalytic reactions. First of all, narrowly-distributed (or monodispersed) poly(methacrylic acid) (PMAA) hollow microspheres with stimuli-responsive properties have been fabricated from the corresponding silica/polymer composite hybrids via a combined distillation-precipitation polymerization and sol-gel chemistry. By such means, hybrid microsphres with alternating SiO2/PMAA layer were further produced by sol-gel process and distillation-precipitation polymerization. Hollow PMAA microspheres with double-shell structures and PMAA-PNIPAM double shelled hollow microspheres were obtained by selective removal of silica core and inter-layer from the alternating SiO2/PMAA/SiO2/PMAA hybrids in HF solutions. The obtained double-shelled PMAA and PMAA-PNIPAM hollow particles could exhibit a reversible volume change to the stimuli of the environmental medium Subsequently, a serial of rattle-type hollow nanospheres with a polymer shell or mesoporous silica shell and various metal nanocore (gold, silver, or anatase titania) were synthesized using the metal/silica core-shell particles as templates. These well-defined rattle hollow hybrid nanospheres, comprising of the two nanostructured functional materials, can be used for confined catalytic reactions as a nanoreactor system. Furthermore, the as-synthesized Ag@air@PMAA hybrid nanorattles with a Ag nanocore, PMAA shell and free space in between. The as-synthesized Ag@air@PMAA hybrid nanorattles were explored as a nanoreactor system for confined catalytic reduction of 4-nitrophenol. The rate of catalytic reaction can be further regulated by controlling molecule diffusion in and out of the stimuli-responsive PMAA shell through the simple variation of environmental stimuli, such as salt (NaCl) concentration of the medium. Lastly, combination of the robust alkyne-azide, thiol-ene `click? chemistry with the living radical polymerization technique has been explored and exhibited a novel strategy for the fabrication of polymer brush-decorated inorganic/polymer core-shell hybrids and polymer hollow spheres. The as-prepared hollow nanospheres with hairy surfaces and multiple functionalities could improve the particle properties and be explored for biomedical applications as a probe for cell imaging and as a vehicle in drug delivery systems (DDSs).
Appears in Collections:Ph.D Theses (Open)

Show full item record
Files in This Item:
File Description SizeFormatAccess SettingsVersion 
LiGL.pdf13.95 MBAdobe PDF



Page view(s)

checked on Dec 8, 2018


checked on Dec 8, 2018

Google ScholarTM


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.