Organic–inorganic mesoporous silica nanostrands for ultrafine filtration of spherical nanoparticles

Sherif A. El-Safty, Moataz Mekawy, Akira Yamaguchi, Ahmed Shahat, Kazuyuki Ogawa, Norio Teramae
2010 Chemical Communications  
Supplementary (S1) S1.1. Synthesis of organic-inorganic mesoporous hybrid AAM In typical conditions, anhydrous toluene (10 ml) solutions containing (3 ml) trymethylchlorosilane (TMCS) and the calcined silica NSs hybrid AAM were refluxed at 80-100 o C for 24 h, under N 2 atmosphere. A 5 ml of dehydrated pyridine was added to the refluxed mixture to remove the resultant Clanions. The total mixture was then refluxed 60 o C for 24 h. The reaction mixture was washed thoroughly with cyclohexane and
more » ... etone to remove the unreacted TMCS. Of these grafting techniques, layered surface chemistry was achieved inside the pore channel by means of a series of dense silanization cycles used to graft TMS to the silica NSs grown in the AAM membranes. 29 Si nuclear magnetic resonance (NMR) spectra (Fig. S1 ESI †) of silica and TMS-silica strands show two main resonance peaks at -110.1 ppm and at -101 ppm, as well as a weak peak at -92 nm. These three peaks correspond to Si(OSi) 4 (Q 4 ), (HO)Si(OSi) 3 (Q 3 ) and (HO) 2 Si(OSi) 2 (Q 2 ) silicate species, respectively. With incorporation of TMS groups into the silica NTs, the Q 3 peak decreased substantially, and a new peak (T l ) appeared at 13 ppm due to silicon bonded to the TMS. Moreover, the increase in the intensity of the siloxane groups' peak (Q 4 ) indicates that Si-OH sites (corresponding to silanediol and silanol groups) in the inner pores of the silica strands underwent condensation with TMS, thus forming covalent linkages to the silica framework. The sharp signal of (M 1 ) corresponds to the main component of the hydrophobic TMS silane, indicating that TMS molecules were located in close proximity of each other in a well-defined monolayer rather than a polymerized random multilayer. Fig. S1.1. 29 Si MAS NMR spectra and a deconvolution of each spectrum of of silica and TMS-modified silica NSs via direct, dense silanization cycles of TMCS. (TMS) (b) TMS-silica NSs (a) Silica NSs Supplementary Material (ESI)
doi:10.1039/c001654c pmid:20428522 fatcat:kjirzpbjxnclzacm36slyyhdma