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

Abstract

A systematic study on the structural properties and component information of periodic mesoporous organosilicas synthesized by using different nonionic surfactants as templates with compressed CO 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 CO 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 CO is illustrated and discussed.

A Facile Route to Synthesis of Hierarchically Porous Carbon via Micelle System for Bifunctional Electrochemical Application

“…As listed in Table 1, microporous diameters of the as-prepared HPCs are distributed in about 0.70 and 1.43 nm, while mesopore sizes are varied with the hydrophobic-chain length of the used surfactants. The mesopore diameters of the HPCs synthesized by F127 and P123 are almost similar (4.56 and 4.75 nm) for the same length of hydrophobic chain, which is larger than that of the F108 (3.85 nm) with a shorter hydrophobic chain (Wang et al, 2017). This result is consistent with that of TEM.…”

“…As shown in Figure 3 , all samples exhibit the well-ordered channel, indicating the universality of the HISA method in micelle systems. The as-prepared HPCs sample with F108 ( Figure 3b1, b2 ) possesses thicker walls than the other samples, which can be attributed to the longest hydrophilic chain and shortest hydrophobic chain of F108 among them ( Wang et al, 2017 ).…”

Pyromellitic diamide–diacid bridged mesoporous organosilica nanospheres with controllable morphologies: a novel PMO for the facile and expeditious synthesis of imidazole derivatives

“…Please do not adjust margins Please do not adjust margins In fact, the synthesis of PMOs depends on many factors such as template and hydrophobic solutes including mesitylene or CO 2 , solvent, temperature, pressure and the synthesis method. 4,5 Therefore, a systematic study should be performed to determine optimal conditions. In this work, the pyromellitic diamide-diacid (PMDADA) precursor (I) was prepared in both THF and DMF at first.…”

“…These high-technology NMs can be used in different areas such as catalysis, smart medicine/drug delivery and formulations, sensors and microelectronic devices, gas storage, optical applications, adsorbents, chromatography, etc. [1][2][3][4][5][6][7][8][9][10][11][12] Mesoporous silica materials (MSMs) have received significant attention from both academia and industry as an important class of NMs. The unique features of MSMs include regular mesoporous structure and tuneable surface properties as well as adjustable pore size which guarantee their widespread applications in drug delivery, gas storage, heterogeneous catalysis, adsorption, batteries and optical devices 3,[13][14][15][16][17][18][19][20][21][22][23][24][25][26] MSMs can be synthesized via two general methods: in acidic or alkaline conditions using different templates.…”

Nonionic Surfactant Properties of Amphiphilic Hyperbranched Polyglycerols

“…Nonionic surfactants are vital for petroleum and metal recovery, personal care products, and detergent formulations . More recently, nonionic surfactants have played a central role in the assembly of various nanostructures such as nanoparticle clusters and mesoporous materials. , However, variations in salt and metal ion concentration, temperature, and pH can influence the stability of the surfactant properties . Compared to their charged counterparts, nonionic surfactants have superior performance, particularly when metals ions are present, which expands their utility in environments such as that found in hard water.…”