One-Step Synthesis of Hydrophobic Multicompartment Organosilica Microspheres with Highly Interconnected Macro-mesopores for the Stabilization of Liquid Marbles with Excellent Catalysis

Abstract

The combination of an emulsion template with polymerization is a very convenient approach to the one-step realization of both simple control porous structures via a change in emulsion formulation and easy functionalization via the concomitant choice of an on-demand monomer. A major challenge of this approach is the inherent instability of the oil/water interface in emulsions, especially the occurrence of chemical reactions in oil or aqueous phases. This study reports the pioneering preparation of highly interconnected macro-mesopores and multicompartment (HIMC) vinyl organosilica microspheres with hydrophobicity by the one-step formation of W/O/W emulsions acting as a template. The emulsion system consists of acidified deionized water, a stabilizer, and vinyltriethoxysilane (VTEO) in which VTEO can be used to produce an organosilica skeleton of the resultant microsphere by a sol-gel process. The study demonstrated that the marvelous stability of W/O/W emulsions aids the formation of multicompartment organosilica microspheres with highly interconnected macro-mesopores by emulsion droplets rather than single-compartment (SC) microspheres. Meanwhile, the internal porous structure and surface morphology of as-prepared organosilica microspheres could be largely tuned by a simple variation of the pH value, the volume fraction of the water phase, and the stabilizer concentration in the initiating multiemulsions. Benefiting from such a well-orchestrated structure and the existence of numerous vinyl groups on the surface, HIMC organosilica microspheres exhibit very high hydrophobicity (with a water contact angle larger than 160°), which allows them to stabilize liquid marbles with excellent stability and high mechanical robustness. Because of its strong catalyst, Ag nanoparticles within HIMC organosilica microspheres enable Ag/HIMC-vinyl organosilica microsphere-based liquid marbles to be an efficient catalytic microreactor, realizing the complete degradation of MB to leuco methylene blue by NaBH in 10 min. The result of this work could provide some guidance for the easy, low-cost, benign preparation of HIMC microspheres having the potential to be excellent supporter of metal nanoparticles or other functionalized compounds for applications in sensing, optoelectronics, and catalysis.

Ultrasonic Preparation of Porous Silica-Dye Microspheres: Sensors for Quantification of Urinary Trimethylamine N-Oxide

“…Factors that affect the performance of colorimetric sensor arrays in response to amines (i.e., response time, sensitivity, reproducibility, selectivity, or susceptibility to interferents) can be heavily influenced by the choice of substrates or sol–gel matrices of the colorants. , Over the past decade, we have been extensively using organically modified silicates prepared by a sol–gel method as host matrices for different sensor elements. , Compared to other porous materials, porous organosilica materials − provide an impressive set of physical and chemical properties including superior chemical resistance to acids or bases, higher heat durability, proper permeability, tunable hydrophobicity or porosity, ease of modification, and ideal optical transparency or reflectivity. These properties provide better control of the sensor media to ensure stable immobilization and solvation of colorants, ample accessibility of colorant centers to analytes, and prevention from leaching or blooming of the dye molecules.…”

Recent advanced development of metal-loaded mesoporous organosilicas as catalytic nanoreactors

“…Such microspheres could be used as an efficient catalytic microreactor to perform the complete degradation of methylene blue to leucomethylene blue by using NaBH 4 in a short time. 238 In addition, Ag-loaded PMO could effectively catalyze the photodegradation of methylene blue and reached an efficient degradation of about 81% within 1 h. 239 Au as a vital noble metal can be immobilized on PMO with or with surface modication. Au can exist in PMO as an Au complex or Au particle form.…”

Nanoporous Silica-Dye Microspheres for Enhanced Colorimetric Detection of Cyclohexanone

“…Porous organosilica materials [37][38][39][40] provide impressive physical and chemical properties including high stability, tunable porosity or hydrophobicity, and ease of modification, which can be selected as sensor media to ensure the robust encapsulation and solvation of chemical dyes, a high contact area for gas exposure, as well as prevention of dye leaching. Porous silica matrices, as host materials, can impressively enhance overall sensitivity of chemo-responsive dyes for gaseous or aqueous detection of relevant analytes of interest.…”