A silane based AIE probe (APTS-TPE) was prepared through the incorporation of (3-Aminopropyl)triethoxysilane (APTS) and tetraphenylethylene (TPE), and applied for in-situ visual monitoring of the silica growth in Stöber process. The TPE groups in the APTS-TPE structure can be anchored in the -Si-O-Si- molecular network and exhibited strong fluorescence emission owing to the restriction of intramolecular motion of TPE group. Real-time in-situ particles size analysis and photoluminescence (PL) intensity analysis were carried out to follow the evolution of PL intensity with particle size. The relationship between silica size and PL intensity in parallel experiments were also discussed. Compared with traditional characterization methods, this method has the potential application for silica industrial production and fundamental research, with the advantage of sensitive, rapid and non-invasive.
For chemical and mechanical polishing/planarization (CMP) applications, the finished surface roughness , polishing efficiency, and defectivity critically depend on the type of abrasive particles and their physical and surface chemical characteristics. Both of core/shell structured inorganic/organic hybrids and porous particles exhibit important potentials in achieving high-efficiency and damage-free CMP. In this work, the polystyrene (PS)-core/mesoporous silica (mSiO 2 )-shell hybrid particles with a comparable shell thickness and tunable core size were synthesized via a modified Stöber process using cetyltrimethylammonium bromide as the template and tetraethyl orthosilicate as the silica precursor. The as-obtained PS/mSiO 2 hybrid particles were characterized by XRD , FT-IR, FESEM , HRTEM , STEM-EDX, HAADF-STEM, DLS, and N 2 sorption-desorption measurements. The mechanical properties (elastic moduli) of PS/mSiO 2 hybrids were investigated via atomic force microscopy (AFM) nano-indentation using Hertz contact model. The effect of the abrasive particle size of PS/mSiO 2 hybrids on CMP performances for oxidized silicon wafers was investigated in terms of root-mean-square ( RMS ) roughness and material removal rate ( MRR ). The PS/mSiO 2 hybrid abrasives presented a reduced roughness and an enhanced MRR with respect to non-porous solid silica abrasives with a comparable particle size. The improved CMP performance might be attributed to the reduction of overall hardness and/or elastic modulus and the improvement of interfacial tribo-chemical wear, resulting from the abundant meso-channels in the silica shells. Furthermore, the RMS roughness and MRR decreased as the PS core size decreased for PS/mSiO 2 hybrids with a comparable mSiO 2 shell thickness. The presented work describes our effort to engineer hybrid abrasives by regulating their polymer core size in order to optimize the CMP performance.
A two-step organic sol–gel process for the preparation of monodispersed or narrow-dispersed melamine–formaldehyde (MF) resin polymer colloidal spheres in water was developed. A modified Stöber process was used to coat the MF colloidal spheres with silica shells, which rendered the surfaces of these colloidal spheres easily modifiable. The prepared MF@silica core–shell composite colloidal spheres were then bioconjugated with bovine serum albumin to demonstrate the feasibility of using these colloidal particles as supporting materials in bioassays. The particle formation mechanism of this organic sol–gel process was investigated by time-resolved microscopic analysis. The prepared MF nano-/microscale resin polymer spheres were monodispersed or narrow-dispersed with a controllable average size ranging from 30 nm to 250 nm and from 0.8 μm to 4.5 μm. The spheres were stable in aqueous or organic solvents and after heat treatment above 300 °C. A “controlled aggregation” model was proposed to explain the influences of the key factors in this process.
危险品化学品经营许可证（带存储）