Radial Mesochannels Research Articles

Fabrication of Silica/Sulfur@Polyaniline Spheres with Radial Mesochannels as Enhanced Cathode Materials for High‐Performance Lithium−Sulfur Batteries

AbstractThe unique structure SiO2/S@polyaniline (PANI) composite with radial meso‐channels was designed and synthesized by in situ chemical oxidative polymerization of aniline on SiO2/S surface. The composite was used as the cathode for lithium−sulfur batteries. The SiO2 nanospheres with radial meso‐channels provided sufficient internal space to accommodate the volume expansion for sulfur and possessed strong adsorption capability for lithium polysulfides (LiPSs). Additionally, the thin PANI coating serving as conductive frameworks generated sufficient electrical conduction paths and effectively prevented the outward diffusion of LiPSs, leading to long‐term stability. Benefitting from the composites’ unique structural and compositional advantages, we obtained an initial specific capacity of 1008.6 mA h g−1 at 0.2 C and an outstanding cycling stability at 1 C rate over 1000 cycles with a capacity decay of 0.04% per cycle. An excellent rate performance of 630.2 mA h g−1 at 2 C was also achieved. Our work reveals the potential application of the porous SiO2@PANI‐based sulfur cathodes in future high‐performance lithium−sulfur batteries. Furthermore, first‐principle calculations and X‐ray photoelectron spectroscopy analysis prove the strong adsorption of LiPSs by the SiO2 surface. The formation of S−O bond on the SiO2 is also found to dominate the adsorption mechanism between LiPSs and SiO2.

Core-template-free synthesis of molecularly ethane-bridged hollow mesoporous silica spheres from acid-hydrolyzed precursor

Molecularly ethane-bridged hollow mesoporous silica spheres with radial mesochannels and enlarged pore size were synthesized by a core-template-free method only through using acid-hydrolyzed TEOS/bis(triethoxysilyl)ethane (BTEE) as precursor.

Upconverting Oil-Laden Hollow Mesoporous Silica Microcapsules for Anti-Stokes-Based Biophotonic Applications.

A recyclable, aqueous phase functioning and biocompatible photon upconverting system is developed. Hollow mesoporous silica microcapsules (HMSMs) with ordered radial mesochannels were employed, for the first time, as vehicles for the post-encapsulation of oil phase triplet-triplet annihilation upconversion (TTA-UC), with the capability of homogeneous suspension in water. In-depth characterization of such upconverting oil-laden HMSMs (UC-HMSMs) showed that the mesoporous silica shells reversibly stabilized the encapsulated UC oil in water to allow efficient upconverted emission, even under aerated conditions. In addition, the UC-HMSMs were found to actively bind to the surface of human mesenchymal stem cells without significant cytotoxicity and displayed upconverted bright blue emission under 640 nm excitation, indicating a potential of our new TTA-UC system in biophotonic applications. These findings reveal the great promise of UC-HMSMs to serve as ideal vehicles not only for ultralow-power in vivo imaging but also for stem cell labeling, to facilitate the tracking of tumor cells in animal models.

Hydrophilic phytic acid-functionalized magnetic dendritic mesoporous silica nanospheres with immobilized Ti4+: A dual-purpose affinity material for highly efficient enrichment of glycopeptides/phosphopeptides

In this work, magnetic mesoporous silica microspheres (Mag-MSMs) with ordered radial mesochannels were fabricated by a self-assembly synthesis in chlorobenzene-water mixed system. Then, the obtained Mag-MSMs were modified with polyethyleneimine (PEI), phytic acid (PA) and Ti4+ (denoted as Mag-MSMs@PEI-PA-Ti4+) via layer by layer (LbL) assembly. Due to the excellent hydrophilicity of PEI and PA and the large amount of Ti4+, the Mag-MSMs@PEI-PA-Ti4+ possessed combined properties of hydrophilic interaction liquid chromatography (HILIC)- and immobilized metal ion affinity chromatography (IMAC)-based materials, which could be used as a dual-purpose material for N-glycopeptides or phosphopeptides enrichment. The proposed Mag-MSMs@PEI-PA-Ti4+ exhibited an outstanding performance for N-glycopeptides enrichment (selectivity: IgG/BSA = 1:1000; sensitivity: 0.5 fmol/μL IgG) and phosphopeptides enrichment (selectivity: α-casein/BSA=1:5000; sensitivity: 0.2 fmol/μL α-casein). Furthermore, after enrichment with Mag-MSMs@PEI-PA-Ti4+, a total of 276 N-glycopeptides assigned to 132 glycoproteins were identified from 2 μL human serum and 1645 phosphopeptides corresponding to 704 phosphoproteins were identified from 200 μg HeLa cell extracts.

Controllable synthesis of hollow periodic mesoporous organosilica spheres with radial mesochannels and their degradable behavior

Hollow periodic mesoporous organosilica spheres with radial mesochannels have been efficiently and controllably synthesized only through introducing a pre-hydrolysis process.

Laccase biosensor fabricated on flower–shaped yolk–shell SiO2 nanospheres for catechol detection

In this study, we developed a facile one–pot strategy for fabricating flower–shaped yolk–shell SiO2 nanospheres (FYSSns) using cetyltrimethylammonium bromide–polyvinylpyrrolidone–cyclohexane–ethanol–water vesicle–microemulsion composite aggregation as templates through a simple solvothermal route. FYSSns displayed yolk–shell structures with flower-shaped yolks (260–320nm) with ordered radial mesochannels (∼7nm), large cavities (100–120nm), and thin silica shells (20–30nm). High laccase immobilization amounts were achieved using FYSSns as supporter, and the laccase–modified FYSSns were applied to the electrochemical sensor with high selectivity for detecting catechol. Under the optimized conditions, the proposed sensor showed a wide linear range from 12.5–450μM over catechol concentration and a low detection limit of 1.6μM. The outstanding performance was attributed to the advantages of FYSSns, such as large specific surface area and its own mesochannel structure.

Double-oxide sulfur host for advanced lithium-sulfur batteries

Although lithium-sulfur batteries show fascinating potential for high-capacity energy storage, their practical applications are hindered by the fast capacity decay and low sulfur utilization at high sulfur loading. Herein we report an efficient sulfur host based on two oxides, in which SiO2 hollow spheres with radial meso-channels are covered by a thin TiO2 coating. SiO2 spheres not only yield high sulfur loading as high as 80wt% but also possess strong lithium polysulfides (LiPS) adsorption capability. The thin TiO2 coating can effectively prevent the LiPS outward diffusion, giving rise to a long-term stability. Meanwhile, the oxide-supported carbon from the carbonization of surfactants enables good electrical conductivity to facilitate electron access and improve sulfur utilization. Experimental and theoretical studies show the strong adsorption of LiPS by SiO2. Benefitting from the unique structural and compositional advantages, we achieve a high sulfur loading up to 80wt% with ~65.5% and 33% capacity retentions over 500 and 1000 cycles when tested at 0.5C and 1C, respectively.

Protic ionic liquid triggered self-assembly structural transition of CTAB for inducing silica spheres with radially oriented mesochannels

Mesoporous silica nanospheres with radially oriented channels have been obtained by adjusting the interaction between cetyltrimethyl ammonium bromide (CTAB) and protic ionic liquid (tripropylamine acetate) through changing the PIL content. The properties of the samples were characterized by N2 adsorption/desorption techniques, scanning electron microscope and transmission electron microscopy. The radially oriented mesochannels, wrinkled surface morphology and particle sizes of the obtained samples were varied with different mass ratios of CTAB to PIL. Compared with silica spheres prepared without PIL, the radial mesochannels slightly bent and degenerated, meanwhile, the particle sizes were decreased from 550 to 350 nm accordingly. Moreover, the formation mechanism of the silica spheres with radially oriented channels and hierarchical porous structure which based on the interaction between PIL and CTAB was tentatively elucidated.

Yolk-shell nanoarchitectures with a Ru-containing core and a radially oriented mesoporous silica shell: facile synthesis and application for one-pot biomass conversion by combining with enzyme.

In this paper, we develop a facile strategy for fabricating a yolk-shell structured catalytic system that consists of a core made of Ru supported on mesoporous carbon, which is encaged within a silica shell that has ordered radial mesochannels. A region-selective etching mechanism for the formation of the yolk-shell nanoarchitectures is proposed based on the stronger adsorption ability of the carbon core for etching agent than that of the silica shell for etching agent. By combining such material with amyloglucosidase, one-pot hydrolysis-hydrogenation of dextrin to sorbitol can be conducted, delivering enhanced efficiency and showing great promise for biomass conversion applications.

Facile Synthesis of Yolk–Shell Structured Inorganic–Organic Hybrid Spheres with Ordered Radial Mesochannels

Facile Synthesis of Yolk–Shell Structured Inorganic–Organic Hybrid Spheres with Ordered Radial Mesochannels

Fabrication of core–shell structured mesoporous silica nanospheres with dually oriented mesochannels through pore engineering

Core–shell structured mesoporous silica nanospheres with penetrating mesochannels in the core and radial mesochannels in the shell.

Mesoporous Silica Hollow Spheres with Ordered Radial Mesochannels by a Spontaneous Self-Transformation Approach

We demonstrate a self-transformation approach for the synthesis of ordered mesoporous silica hollow spheres with radially oriented mesochannels. The method is simple and facile, in which mesostructured silica spheres synthesized in a Stober solution can spontaneously transform to hollow structure when they are incubated with water. The formation of the hollow structure does not require any sacrificial templates, emulsion droplets, or surface protective agents. The obtained mesoporous silica hollow spheres possess controllable diameter, tunable shell thickness, high specific surface area, and uniform mesopore. Transmission electron microscopy (TEM) observations show that the formation of the hollow spheres undergoes a selective etching process in the inner section. 29Si NMR spectra and detailed reactions demonstrate that the solid-to-hollow transformation of the Stober silica spheres in water is attributed to the difference in the degree of condensation of silica between their outer layer and inner section...

Fine‐Tuning Mesochannel Orientation of Organically Functionalized Mesoporous Silica Nanoparticles

AbstractThree orientations to choose from: 2D hexagonal organically functionalized mesoporous silica nanoparticles with tunable mesochannel orientation (straight, helical, and radial mesochannels) were synthesized through a simple addition of various amounts of ureidopropyltrimethoxylsilane (UDPTMS) in the condensation of tetraorthosilicate (TEOS) in aqueous solution.magnified image