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Title: Synthesis of half-sphere/half-funnel-shaped silica structures by reagent localization and the role of water in shape control

Role of water and ammonium hydroxide is investigated in evolution of shape of silica structures in the polyvinylpyrrolidone-pentanol emulsion droplet system. Shape control of silica structures is demonstrated by localization of the reagents. A uniform dispersion of reagents provided straight silica rods, while localization of the reagents at the emulsion droplet periphery provided a new type of structures half sphere-half funnel. The absence of water in the initial stages prompted a different nucleation process for the structure growth compared to when water was present in the intial stages. Effect of effective water concentration appeared to be related to the ease of diffusion of silica percursor inside the emulsion droplet,i.e., the higher the water concentration, the lower the silica precursor diffusion. Additionally, mixing the reagents in different combinations before adding to the reaction mixture also affected the silica structure thickness, length, and shape.
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Chemistry - A European Journal
Additional Journal Information:
Journal Volume: 22; Journal Issue: 52; Journal ID: ISSN 0947-6539
Publisher:
ChemPubSoc Europe
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; silica structures; shape control; mechanism
OSTI Identifier:
1337849

Datskos, Panos, Polizos, Georgios, Cullen, David A., Bhandari, Mahabir, and Sharma, Jaswinder. Synthesis of half-sphere/half-funnel-shaped silica structures by reagent localization and the role of water in shape control. United States: N. p., Web. doi:10.1002/chem.201604130.
Datskos, Panos, Polizos, Georgios, Cullen, David A., Bhandari, Mahabir, & Sharma, Jaswinder. Synthesis of half-sphere/half-funnel-shaped silica structures by reagent localization and the role of water in shape control. United States. doi:10.1002/chem.201604130.
Datskos, Panos, Polizos, Georgios, Cullen, David A., Bhandari, Mahabir, and Sharma, Jaswinder. 2016. "Synthesis of half-sphere/half-funnel-shaped silica structures by reagent localization and the role of water in shape control". United States. doi:10.1002/chem.201604130. https://www.osti.gov/servlets/purl/1337849.
@article{osti_1337849,
title = {Synthesis of half-sphere/half-funnel-shaped silica structures by reagent localization and the role of water in shape control},
author = {Datskos, Panos and Polizos, Georgios and Cullen, David A. and Bhandari, Mahabir and Sharma, Jaswinder},
abstractNote = {Role of water and ammonium hydroxide is investigated in evolution of shape of silica structures in the polyvinylpyrrolidone-pentanol emulsion droplet system. Shape control of silica structures is demonstrated by localization of the reagents. A uniform dispersion of reagents provided straight silica rods, while localization of the reagents at the emulsion droplet periphery provided a new type of structures half sphere-half funnel. The absence of water in the initial stages prompted a different nucleation process for the structure growth compared to when water was present in the intial stages. Effect of effective water concentration appeared to be related to the ease of diffusion of silica percursor inside the emulsion droplet,i.e., the higher the water concentration, the lower the silica precursor diffusion. Additionally, mixing the reagents in different combinations before adding to the reaction mixture also affected the silica structure thickness, length, and shape.},
doi = {10.1002/chem.201604130},
journal = {Chemistry - A European Journal},
number = 52,
volume = 22,
place = {United States},
year = {2016},
month = {11}
}