A facile template route to periodic mesoporous organosilicas nanospheres with tubular structure by using compressed CO2

A Novel Hydrate Form of Sodium Dodecyl Sulfate and Its Crystallization Process

A novel hydrate form of sodium dodecyl sulfate (SDS) was firstly discovered through a hydrate screening with the use of organic solvents, while SDS is generally prepared solely in aqueous media. Surprisingly, a novel SDS hydrate form with needle-shaped crystals produced by adding acetonitrile to a 20 wt % SDS aqueous solution at a ratio of 3:1 (v/v) and further cooling to around 5 °C could be found with a trace amount in one of the two purchased SDS products that we examined. After comprehensive solid-state characterizations by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), Raman spectroscopy, dynamic vapor sorption (DVS), and elemental analysis (EA), it is also successfully made directly from the synthesis of SDS through esterification and saponification. Four times the equal proportion of acetone was added into the reaction solution at an interval of 5 min to separate the side product, sodium sulfate, from the mother liquor. The desired novel hydrate form of SDS was then obtained by cooling the filtered mother liquor to 5 °C and aged for 8 h for a preferential growth.

Bi-functionalized aminoguanidine-PEGylated periodic mesoporous organosilica nanoparticles: a promising nanocarrier for delivery of Cas9-sgRNA ribonucleoproteine

BACKGROUND

There is a great interest in the efficient intracellular delivery of Cas9-sgRNA ribonucleoprotein complex (RNP) and its possible applications for in vivo CRISPR-based gene editing. In this study, a nanoporous mediated gene-editing approach has been successfully performed using a bi-functionalized aminoguanidine-PEGylated periodic mesoporous organosilica (PMO) nanoparticles (RNP@AGu@PEG1500-PMO) as a potent and biocompatible nanocarrier for RNP delivery.

RESULTS

The bi-functionalized MSN-based nanomaterials have been fully characterized using electron microscopy (TEM and SEM), nitrogen adsorption measurements, thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), and dynamic light scattering (DLS). The results confirm that AGu@PEG1500-PMO can be applied for gene-editing with an efficiency of about 40% as measured by GFP gene knockdown of HT1080-GFP cells with no notable change in the morphology of the cells.

CONCLUSIONS

Due to the high stability and biocompatibility, simple synthesis, and cost-effectiveness, the developed bi-functionalized PMO-based nano-network introduces a tailored nanocarrier that has remarkable potential as a promising trajectory for biomedical and RNP delivery applications.

Facile synthesis of a mesoporous TiO2 film templated by a block copolymer for photocatalytic applications

Large-sized mesoporous TiO2 through a polymeric micelle assembly approach for photocatalysts.

Mesoporous Silica vs. Organosilica Composites to Desulfurize Diesel

The monolacunary Keggin-type [PW₁₁O₃₉]⁷⁻ (PW₁₁) heteropolyanion was immobilized on porous framework of mesoporous silicas, namely SBA-15 and an ethylene-bridged periodic mesoporous organosilica (PMOE). The supports were functionalized with a cationic group (N-trimethoxysilypropyl-N, N, N-trimethylammonium, TMA) for the successful anchoring of the anionic polyoxometalate. The PW₁₁@TMA-SBA-15 and PW₁₁@TMA-PMOE composites were evaluated as heterogeneous catalysts in the oxidative desulfurization of a model diesel. The PW₁₁@TMA-SBA-15 catalyst showed a remarkable desulfurization performance by reaching ultra-low sulfur levels (<10 ppm) after only 60 min using either a biphasic extractive and catalytic oxidative desulfurization (ECODS) system (1:1 MeCN/diesel) or a solvent-free catalytic oxidative desulfurization (CODS) system. Furthermore, the mesoporous silica composite was able to be recycled for six consecutive cycles without any apparent loss of activity. The promising results have led to the application of the catalyst in the desulfurization of an untreated real diesel supplied by CEPSA (1,335 ppm S) using the biphasic system. The system has proved to be a highly efficient process by reaching desulfurization values higher than 90% for real diesel during three consecutive cycles.

Hydrophobicity-responsive engineered mesoporous silica nanoparticles: application in the delivery of essential nutrients to bacteria combating oil spills

Facile chemical modification of mesoporous silica particles allows the production of gated reservoir systems capable of hydrophobicity-triggered release. Applied to the delivery of nutrients specifically to an oil phase, the systems developed have been shown to reliably assist the bacterial degradation of hydrocarbons. The gated system developed, made of C₁₈ hydrocarbon chains, is demonstrated to be in a closed collapsed state in an aqueous environment, yet opens up through solvation by lipophilic alkanes and releases its content on contact with the oil phase.

CO2-Assisted synthesis of hierarchically porous carbon as a supercapacitor electrode and dye adsorbent

A facile and sustainable strategy was developed for the fabrication of hierarchically porous carbons with tunable pore size distributions and architectures.

Gold/Periodic Mesoporous Organosilicas with Controllable Mesostructure by Using Compressed CO2

Gold nanoparticles confined into the walls of periodic mesoporous organosilicas (PMOs) with controllable morphology have been successfully fabricated through a one-pot method by using different CO₂ pressures. The synthesis can be easily conducted in a mixed aqueous solution by using HAuCl₄ as gold source and bis[3-(triethoxysilyl)propyl] tetrasulfide and tetramethoxysilane as the organosilica precursor. P123 and compressed CO₂ served as the template and catalytic/regulative agent, respectively. Transmission electron microscopy, N₂ adsorption, and X-ray diffraction were employed to characterize the structure of the obtained composite materials. To further investigate the formation mechanism, a series of ordered PMOs with one-dimensional nanotube, two-dimensional hexagonal, vesicle-like, and cellular foam structures were obtained by using different CO₂ pressures without the gold source. The mechanism for mesostructure evolution of PMOs with different CO₂ pressures was proposed and discussed in detail. The catalytic performance of Au-based PMOs was evaluated for the reduction of 4-nitrophenol (4-NP). These obtained composites with different mesostructures not only exhibit excellent catalytic activity, high conversion rate, and remarkable thermal stability, but they also exhibit morphology-dependent reaction properties in the reduction of 4-NP. The possible reaction pathway of the reactants to embedded Au active sites was proposed and schemed.

Investigation on the function of nonionic surfactants during compressed CO2-mediated periodic mesoporous organosilica formation

A systematic study on the structural properties and component information of periodic mesoporous organosilicas synthesized by using different nonionic surfactants as templates with compressed CO₂ was carried out. Triblock copolymers (F127, F108, and P123), oligomeric alkyl poly(ethylene oxide) (Brij-58 and Brij-76), and alkyl-phenol poly(ethylene oxide) (TX-100) have been employed as templates and BTEB as a bridged organosilica precursor to synthesize PMO materials at 5.90 MPa. The structure and morphology of the obtained materials were investigated by means of transmission electron microscopy (TEM), nitrogen sorption isotherms, solid Si and C NMR, and FTIR. Efforts have also been made to compare the differences in structural and morphological properties among these samples synthesized under similar conditions. We also investigate the synthesis of PMOs using F127 as the template at different CO₂ pressures. It was found that the interaction between different organic silica precursors and surfactants with a variety of hydrophilic and hydrophobic chains is the key factor for the disorder degree of mesostructures. On this basis, the possible mechanism of formation of PMOs synthesized using a nonionic surfactant (triblock copolymer) as the template with compressed CO₂ is illustrated and discussed.