TY - JOUR
T1 - The structure of colloidal polyethylenimine–silica nanocomposite microparticles
AU - Semenova, Alexandra
AU - Giles, Luke W.
AU - Vidallon, Mark Louis P.
AU - Follink, Bart
AU - Brown, Paul L.
AU - Tabor, Rico F.
N1 - Funding Information:
The authors acknowledge the use of instruments and assistance at the Monash Centre for Electron Microscopy (MCEM) , a Node of Microscopy Australia. This research used equipment funded by Australian Research Council grant ( LE0882821 ). Use of equipment and the technical assistance at Monash X-ray Platform and Monash Analytical Platform are also gratefully acknowledged. This project was supported by an Australian Government Research Training Program (RTP) Scholarship, and in part by the grant of an Australian Research Council Discovery Project ( DP210102677 ).
Funding Information:
Transmission electron microscopy (TEM) images of the microgel, standard composite and etched ‘skeletons’ support the SEM observations (Fig. 6). The majority of the microgel particles appear very smooth, without any pattern of the internal matter distribution. Particles of the standard composite had slightly higher density and a distinct granular pattern originating from deposited silica seeds. Etched particles demonstrated electron density reduction, following the removal of polymer, while keeping the same granular pattern as the original composite. Both the SEM and TEM observations indicate an even distribution of nanoscale granular silica throughout the entire body of the composite particle. However, they do not answer questions about the organisational relationship between the PEI microgel and silica phase. Partly, this lack of information was caused by the nature of the microgel, which has relatively low electron density, is not stable enough under the electron beam and high vacuum environment and is strongly charging, reducing the maximal resolution for its imaging.The authors acknowledge the use of instruments and assistance at the Monash Centre for Electron Microscopy (MCEM), a Node of Microscopy Australia. This research used equipment funded by Australian Research Council grant (LE0882821). Use of equipment and the technical assistance at Monash X-ray Platform and Monash Analytical Platform are also gratefully acknowledged. This project was supported by an Australian Government Research Training Program (RTP) Scholarship, and in part by the grant of an Australian Research Council Discovery Project (DP210102677).
Publisher Copyright:
© 2022 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences
PY - 2023/5
Y1 - 2023/5
N2 - Deposition of silica from an organosilane tetraethoxysilane (TEOS) onto parent polyethylenimine (PEI) microgel particles produces a novel PEI–silica nanocomposite, which possesses greater adsorption capacity for copper ions than either parent material. This study explores factors governing interactions of silica with the PEI matrix, along with structural features of resulting PEI–silica composite particles, to explain their properties and determine their application potential. The influence of initial TEOS/PEI mass ratio and the duration of silica deposition on the final silica content and distribution in the composite are studied. A comparative analysis of the structural architecture of chemically etched silica remnants, original PEI–silica composite particles and the parent PEI-microgel is carried out using X-ray photoelectron spectroscopy, small-angle X-ray scattering, and electron microscopy techniques. It is found that silica sol nanoparticles are evenly distributed throughout the PEI-microgel framework and interlinked with it via electrostatic interactions, enabling a structural model of the PEI–silica nanocomposite to be proposed. The chemical stability of resulting nanocomposite particles in parallel with the parent PEI-microgel is tested and shown to be robust for more than 100 days of storage in aqueous dispersions across a range of pH conditions, highlighting the application potential for these particles in copper capture.
AB - Deposition of silica from an organosilane tetraethoxysilane (TEOS) onto parent polyethylenimine (PEI) microgel particles produces a novel PEI–silica nanocomposite, which possesses greater adsorption capacity for copper ions than either parent material. This study explores factors governing interactions of silica with the PEI matrix, along with structural features of resulting PEI–silica composite particles, to explain their properties and determine their application potential. The influence of initial TEOS/PEI mass ratio and the duration of silica deposition on the final silica content and distribution in the composite are studied. A comparative analysis of the structural architecture of chemically etched silica remnants, original PEI–silica composite particles and the parent PEI-microgel is carried out using X-ray photoelectron spectroscopy, small-angle X-ray scattering, and electron microscopy techniques. It is found that silica sol nanoparticles are evenly distributed throughout the PEI-microgel framework and interlinked with it via electrostatic interactions, enabling a structural model of the PEI–silica nanocomposite to be proposed. The chemical stability of resulting nanocomposite particles in parallel with the parent PEI-microgel is tested and shown to be robust for more than 100 days of storage in aqueous dispersions across a range of pH conditions, highlighting the application potential for these particles in copper capture.
KW - Nano-scale morphology
KW - Organic-inorganic composite
KW - Polyethylenimine
KW - Silica
KW - Small angle X-ray scattering
UR - http://www.scopus.com/inward/record.url?scp=85137381102&partnerID=8YFLogxK
U2 - 10.1016/j.partic.2022.07.015
DO - 10.1016/j.partic.2022.07.015
M3 - Article
AN - SCOPUS:85137381102
VL - 76
SP - 86
EP - 100
JO - Particuology
JF - Particuology
SN - 1674-2001
ER -