Preparing titania aerogel monolithic chromatography columns using supercritical carbon dioxide

Abstract

The search for a method to fabricate monolithic inorganic columns has attracted significant recent attention due to their unique ability in separation applications of various biomolecules. Silica and polymer based monolithic columns have been prepared, but titania and other metal oxide monoliths have been elusive, primarily due to their fragility. This article describes a new approach for preparing nanostructured titania based columns, which offer better performance over conventional particle packed columns for separating a wide variety of biomolecules including phosphopeptides. TiO(2) monolithic aerogels were synthesized in separation columns using in situ sol-gel reactions in supercritical carbon dioxide (scCO(2)) followed by calcination, and compared to those prepared in heptanes. The characterization results show that scCO(2) is a better solvent for the sol-gel reactions, providing lower shrinkage with the anatase TiO(2) monolith composed of nanofibers with very high surface areas. The monolithic columns show the ability to isolate phosphopeptides with little flow resistance compared to conventional titania particle based microcolumns.

Binder-Free TiO2 Monolith-Packed Pipette Tips for the Enrichment of Phosphorylated Peptides

“…The macroporous monolithic structure is beneficial for increased surface area and reduced flow resistance, which allows specific entrapment of TiO 2 monolith inside the tips for efficient sample pretreatment (Scheme 1c). [13] The use of T-tip for p-ERK1 peptide enrichment enables a detection limit of 1 ng mL À1 , showing a better enrichment efficiency compared with the commercial NuTip.…”

Preparation of <i>p</i>-Aramid Aerogels Using Supercritical CO₂

“…Thus, aerogels are extensively used as thermal insulation materials, chemical absorbers or reinforcing materials [1][2][3][4][5][6][7]. On the other hand, p-aramid fibers, such Kevlar ® that is alternating copolymer of terephthaloyl chloride (TPA) and p-phenylenediamine (PPD), and Technora ® prepared from TPA, PPD and 3, 4'-diaminodiphenyl ether in a 50/25/25 mole ratio, have the characteristics of high strength, high heat resistance and toughness.…”

“…However, despite a great amount of literatures had already been published including inorganic (e.g. silica [2], alumina [3], titania [4]) and organic (e.g. carbon [5], polylactic [6], cellulose [7]) aerogels, a detailed study of the operation process condition is still missing.…”

Nano-Doped Monolithic Materials for Molecular Separation

“…Some of the other reported techniques utilised in the preparation of titanium monoliths include; (i) sol-gel [144]; phase separation induced [145]; template free sol-gel process with phase separation [146]; templated sol-gel process [147].Černigoj, Gašperšič, Fichtenbaum, Lendero Krajnc, Vidič, Mitulović, and Štrancar [140] recently created a methacrylate based monolith with immobilised TiO 2 nanoparticles for the enrichment of phosphorylated peptides under low salt concentrations and wide pH variation. Another form of titania monoliths also used for the enrichment of phosphorylated proteins is an aerogel monolith developed by Sui, Liu, Lajoie, and Charpentier [28] using supercritical carbon dioxide. The use of supercritical fluid is known to improve the wettability, enhance mass transfer and annihilate the occurrence of shrinkage due to the absence of surface tension [28].…”

“…Another form of titania monoliths also used for the enrichment of phosphorylated proteins is an aerogel monolith developed by Sui, Liu, Lajoie, and Charpentier [28] using supercritical carbon dioxide. The use of supercritical fluid is known to improve the wettability, enhance mass transfer and annihilate the occurrence of shrinkage due to the absence of surface tension [28].…”