Synthesis of amino-functionalized mesoporous silica sheets and their application for metal ion capture

Abstract

a b s t r a c tNovel mesoporous silica sheets with surface amino-functional groups (sheet-NH 2 ) were prepared for the efficient adsorption of aqueous metal ions. The sheet-NH 2 were synthesized by a dual-templating process using Pluronic P123 and N-palmitoyl-l-alanine as templates. Two silicone regents were used to form the silica framework: tetraethoxysilane and 3-aminopropyltriethoxysilane. In the synthetic process, the as-prepared silicate was refluxed in ethanol to remove the organic templates remaining from the surface amino groups derived from APTES. The prepared sheet-NH 2 showed widths of several micrometres and small thicknesses of approximately 50 nm. The pore diameter, pore volume and BET surface area of sheet-NH 2 were determined by nitrogen adsorption-desorption isotherms to be 3.1 nm, 0.73 cm 3 g −1 and 189.9 m 2 g −1 , respectively. TEM, XRD, FT-IR and TG-DTA analysis demonstrated that the sheet material had a disordered mesoporous structure and contained organic chains. The adsorptions of aqueous zinc(II) and copper(II) metal ions were examined and compared with amino-functionalized conventional mesoporous silica (MCM-NH 2 ), calcined mesoporous silica sheets and silica beads with no porous structures. Notably, the sheet-NH 2 exhibited the highest adsorption of both zinc and copper ions among the examined materials. In addition, the metal ion sorption equilibrium data of sheet-NH 2 were fitted to the Langmuir isotherm model.

Antimicrobial photodynamic activity of toluidine blue encapsulated in mesoporous silica nanoparticles againstPseudomonas aeruginosaandStaphylococcus aureus

“…The extra peaks, apart from the MSN peaks, in TB MSN at 2,830, 2,910 and 3,518 cm À1 clearly show the presence of TB in MSN. These peaks of TB and MSN agree well with previous reports (Ganguly et al 2013;Nakanishi et al 2015;Khosraviyan et al 2016). HR-TEM micrographs revealed the size, shape, and dispersity of TB MSN.…”

Ionic liquid microemulsion‐mediated in situ thermosynthesis of poly(ionic liquid)s and their adsorption properties for Zn(II)

“…Moreover, the n value greater than 1 showed that the adsorption of Zn(II) onto PAM‐2.5b was favorable. The maximum adsorption capacity was greater than the value of various reported adsorbent for Zn(II) removal (Table ) , indicating that the PAMs in situ thermosynthesized by PDILMs could effectively remove Zn(II) from waste water.…”

A Highly Sensitive Impedimetric DNA Biosensor Based on Hollow Silica Microspheres for Label-Free Determination of E. coli

“…The absorption band at 949 cm −1 (Si-OH) indicated the high concentration of the silanol group [23]. After calcination at 620°C for 6 h, the absorption band at 1065 cm −1 (Si-O-Si asymmetric stretching) became sharper and the absorption band at 949 cm −1 (Si-OH bending vibration) disappearred [24] due to condensation of the silanol group, changing into the Si-O-Si network [25]. Si-O-Si symmetric vibration stretching shifted from 806 cm −1 to 789 cm −1 , and the intensity of the absorption band increased due to the formation of the SiO 2 network [26].…”