Facile Fabrication of Lilium Pollen-like Organosilica Particles

Abstract

Organosilica particles with a novel lilium pollen-like morphology were synthesized by a one-step sol–gel method. The hydrolysis and co-condensation of vinyltrimethoxysilane (VTMS) and tetraethoxysilane (TEOS) took place in an aqueous medium with ammonia as the catalyst. The growth process of the organosilica particles was tracked by scanning electron microscopy (SEM). The bulk and surface composition of the lilium pollen-like organosilica particles were characterized by solid-state 29Si nuclear magnetic resonance (NMR) spectroscopy and X-ray photoelectron spectroscopy (XPS), respectively. In addition, bowl-like, golf ball-like, and walnut kernel-like organosilica particles could also be obtained by changing the concentration of ammonia, the amount of silane precursors, or the reaction medium. This study provides a facile method to prepare nonspherical organosilica particles with controllable morphologies.

Dynamically shaping the surface of silica colloids

“…Our observations so far, and the majority of previous studies, have focused on the impact of reaction composition on the final particle morphology. 32,33 However, we found interesting differences when following the particle morphology in time for three of the syntheses reported in Fig. 1, i.e.…”

“…Our parameter sweep enables us to recover all of the particle morphologies previously reported in the literature, going from smooth to ''bowl-like'' particles passing through ''golf-ball'' and ''Lilium-pollen'' morphologies. 32,33 Often, the highly buckled ''bowl-like'' particles completely flatten out into disk-like objects, whose dimensions are difficult to evaluate systematically.…”

“…Among the different choices, an interesting synthesis route involves the use of tetraethyl orthosilicate (TEOS) and vinyltrimethoxysilane (VTMS) as silica precursors, which allows forming a broad range of particle morphologies, including ones that have been likened to golf balls and Lilium pollen. 32 While previous works demonstrated clear qualitative differences in the particle morphology as a function of reaction conditions, 32,33 the specific range of synthesis parameters that allows precise surface modulation, as required in the abovementioned processes, is currently less defined. Most importantly, a quantification of surface topography in relation to the synthesis parameters, which can be used as a guideline for the design of rough particles with tailored surfaces, remains open.…”

Facile Morphology Control during Rapid Fabrication of Nanosized Organosilica Particles

“…Recent studies have emphasized the importance of controlling the competitive hydrolysis–condensation reactions of silicon precursors in order to fabricate organosilica NPs with different morphologies. ,, Therefore, we first investigate the influence of different feeding weight ratios of precursors on the fabrication of organosilica NPs by using MTMS and VTMS as the coprecursors. The experimental conditions for the preparation of organosilica NPs are summarized in Table .…”

“…It is noteworthy that there are substantial number of non-cross-linked organic groups in the network, leading to different cross-linking degrees of the organosilica network because of the hydrophobic interaction of organic groups (Scheme ). Hence, the local difference of organosilica density at the interface of the organosilica NPs is generated, which could make enough stress force for the formation of a wrinkled surface structure, , resulting in the golf ball-like organosilica NPs. Based on the probable mechanism proposed, when the silicon precursors with different organic moieties are used in the reaction system (such as ethane-bridged or phenyl groups), the resultant organosilica NPs seem to show an unexpected morphology for versatile applications.…”