Bioinspired Approach to Silica Nanoparticle Synthesis Using Amine-Containing Block Copoly(vinyl ethers): Realizing Controlled Anisotropy

Abstract

Core–shell polymer–silica hybrid nanoparticles smaller than 50 nm in diameter were formed in the presence of micelles of poly­(2-aminoethyl vinyl ether-block-isobutyl vinyl ether) (poly­(AEVE m -b-IBVE n )) through the hydrolysis and polycondensation of alkoxysilane in aqueous solution at a mild pH and temperature. The size of the nanoparticles as well as the number and size of the core parts were effectively controlled by varying the molecular weight of the copolymers. The polymers could be removed by calcination to give hollow silica nanoparticles with Brunauer–Emmett–Teller surface areas of more than 500 m2 g–1. Among these, silica nanoparticles formed with poly­(AEVE115-b-IBVE40) displayed an anisotropy of single openings in the shell. The use of an alternative copolymer, poly­(AEVE-b-2-naphthoxyethyl vinyl ether) (poly­(AEVE113-b-βNpOVE40)), yielded core–shell nanoparticles with less pronounced anisotropy. These results showed that the degree of anisotropy could be controlled by the rigidity of micelles; the micelle of poly­(AEVE115-b-IBVE40) was more deformable during silica deposition than that of poly­(AEVE113-b-βNpOVE40) in which aromatic interactions were possible. This bioinspired, environmentally friendly approach will enable large-scale production of anisotropic silica nanomaterials, opening up applications in the field of nanomedicine, optical materials, and self-assembly.

Bioinspired Scaffolding by Supramolecular Amines Allows the Formation of One‐ and Two‐Dimensional Silica Superstructures

“…[4] These features modifythe nucleationf ree energy barriera nd nucleation kinetics of silica, which ultimately governt he growth into well-defineds tructures. [5][6][7][8][9][10] Building upon the lessons learned from insightful work on biomineralization, numerouss ilica production strategies have used amine-bearing polymers such as poly(ethyleneimine), [11][12][13] polylysine, [14][15][16][17][18][19] peptides, [20][21][22] and block copolymers [23][24][25][26] to obtainh ighlyi ntricate structures. This methodi sa dvantageous because the amine-rich polymers not only serve as as caffold but also act as acatalysttopromote the condensation of silicic acid.…”

“…Building upon the lessons learned from insightful work on biomineralization, numerous silica production strategies have used amine‐bearing polymers such as poly(ethyleneimine), [11–13] polylysine, [14–19] peptides, [20–22] and block copolymers [23–26] to obtain highly intricate structures. This method is advantageous because the amine‐rich polymers not only serve as a scaffold but also act as a catalyst to promote the condensation of silicic acid.…”

Silicification of Amine-Epoxide Cationic Microgels: An In Vitro Investigation

“…Besides water-soluble aminated species, colloidal systems bearing amine moieties have found usage for silica synthesis, examples including micelles, , latex particles, , and microgels (MGs). − The use of MGs as a template for silica formation is particularly easy for large-scale synthesis, easy to control the size, and relatively convenient to functionalize. Unlike the smooth surface obtained by using the traditional Stöber method or micelles as templates to synthesize hybrid particles, swollen MGs promote the formation of rough surfaces by hybrid particles due to their porous properties.…”

“…12 Polyallylamine has also been shown as a potential synthetic substitute for proteins in biomimetic synthesis of silica particles. 13 Besides water-soluble aminated species, colloidal systems bearing amine moieties have found usage for silica synthesis, examples including micelles, 14,15 latex particles, 16,17 and microgels (MGs). 18−21 The use of MGs as a template for silica formation is particularly easy for large-scale synthesis, easy to control the size, and relatively convenient to functionalize.…”