Functionalization of mesoporous silica surface with carboxylic groups by Meldrum’s acid and its application for sorption of proteins

Abstract

A new method of silica surface functionalization with carboxyl groups is proposed based on the reaction between 2,2-dimethyl-1,3-dioxane-4,6-dione (Meldrum's acid, MA) and the surface silanol groups. For the first time such a post-synthesis modification was successfully applied to silica materials. Although silica surface is successfully carboxylated (as evidenced by FTIR and XPS), the porosity, ordering and morphology remain practically unchanged after the proposed post-synthesis treatment (as confirmed by nitrogen sorption, XRD and electron microscopy). Adsorption study of model biomolecules (lysozyme and bovine serum albumin) shows that different surface chemistries (-OH vs.-COOH) lead to different affinities between the silica surface and sorbates.

Tailoring Nanoadsorbent Surfaces: Separation of Rare Earths and Late Transition Metals in Recycling of Magnet Materials

“…To increase the amount of functional groups on the silica surface, SiO 2 NPs were pre-treated by washing with nitric acid. It is known that functionalization of different groups takes place at surface hydroxy sites, and thus it is very dependent on the presence of surface silanol groups [ 41 ]. To reach maximum silane capacity, several pre-treatment methods have previously been developed, including washing with acids, piranha solution, and UV-ozonolysis [ 42 ].…”

Structure-Property Relationship for Different Mesoporous Silica Nanoparticles and its Drug Delivery Applications: A Review

“…Grafting is a type of post-fabrication process used to modify the surface of pre-fabricated porous silica material which bonds the functional groups connected to their surface after removing the surfactant ( Zhang et al, 2004 ; Lesaint et al, 2005 ). The abundant silanol groups present on the surface of the silica porous material are applied as suitable junctions for functionalization with organic functional groups ( Figure 5 ) ( Barczak, 2019 ).…”

“…After removal of the surfactant, the organosilanes can be attached to the silanol channels using trichloro organosilanes or trialkoxy organosilanes ( Barczak, 2019 ). A series of organosilanes including amine ( Aguado et al, 2009 ), thiol ( Li et al, 2011 ), chloride ( Han et al, 2003 ), cyano ( Prouzet et al, 1999 ), ester ( Prouzet et al, 1999 ), aldehyde ( Yin et al, 2020 ), epoxy ( Yeganeh et al, 2019 ), anhydride ( Park et al, 2019 ), isocyanate ( Ratirotjanakul et al, 2019 ), phosphor ( Yamada et al, 2019 ), imidazole ( Nuri et al, 2019 ), ammonium ( Lagarde et al, 2019 ), acryl ( Xiao Song et al, 2019 ), alkyl ( Nuntang et al, 2019 ), and phenyl ( Gao et al, 2019 ) are available for application in the grafting procedure.…”

A comprehensive review of bioactive glass: synthesis, ion substitution, application, challenges, and future perspectives

“…The sol-gel method has significantly been used owing to the restrictions mentioned. Because of its higher surface Si-OH groups, It's into greater functionalizing ability [67]. The sol-gel method can occur by basic or acidic methods that influence the resulting material characteristics.…”