Aminopropyltriethoxysilane grafting

Anchored amine materials can be prepared through a number of synthetic methodologies. Because of the potential importance of these materials to organic synthesis, a ninhydrin assay was developed as a rapid laboratory determination of available surface amines. The assay agreed well with expected values for aminopropyltriethoxysilane grafted onto commercial silica. The assay also distinguished between reactive amines and protonated or poisoned surface amines on co-condensed SBA-15 materials. 

Preparation of Grafted Amine-Functionalized Silica. Silica was pressed, cmshed, and sieved to 40-60 mesh particles and calcined at 550°C overnight. To anhydrous toluene (40 mL), silica (1.0 g) was added under N2 and stirred for an hour. Aminopropyltriethoxysilane (APS 1.0 g, 5.58 mmol) was syringed into mixture and stirred for 24 hours at room temperature under nitrogen. The functionalized silica was then filtered, washed with toluene three times, and dried under vacuum at 50°C. 

Huq and Mercier191 synthesized cyclodextrin modified silicas by first coupling the cyclodextrin units to 3-aminopropyltriethoxysilane (APTES) and then subjecting it to a co-condensation reaction with TEOS (Fig. 3.15c). Interestingly, all attempts to anchor cyclodextrins by grafting onto previously thiol-functionalized silicas have been unsuccessful. It has also been demonstrated that the cyclodextrin units on the... 

The primary amino groups were anchored to the MTS silica surface through the grafting of 3-aminopropylsilane to the siloxy groups (sUanol, sUoxane) by treatment with refluxing anhydrous toluene solution of 3-aminopropyltriethoxysilane (scheme 2, eq. 2). 

Starch has been grafted with such silyl compounds such as 4-aminopropyltriethoxysilane to give a reinforced polymer that was subsequently reacted with maleic anhydride in the presence of benzoyl peroxide.3267... 

Their work is summarized briefly Silica xerogels and MCM-48 were used. The xerogels were prepared from tetraethoxysilane (TEOS) by using standard technique, and the MCM-48 was prepared by the techniques developed by Schumacher et al. (2000). These silicas were used because of their high surface areas (816 m /g for xerogels, and 1389 m /g for MCM-48) and high silanol numbers ( 5 and 8, respectively), as well as thermal stability (MCM-48 is more stable than MCM-41). 3-Aminopropyltriethoxysilane was grafted on these silicas. 

Yamamoto H, Horn F (1994) In situ crystallization of bacterial cellulose I. Influences of polymeric additives, stirring and temperature on the formation celluloses 1 a and I p as revealed by cross polarization/magic angle spinning (CP/MAS)13C NMR spectroscopy. Cellulose l(l) 57-66 Yuan P, Southon PD, Liu Z, Green MER, Hook JM, Antill SJ, Kepert CJ (2008) Functionalization of halloysite clay nanotubes by grafting with y-aminopropyltriethoxysilane. J Phys Chem C 112(40) 15742-15751... 

A third method involves the preparation of a poly(amido-amine) containing Y aminopropyltriethoxysilane groups as side substituents. This poly(amido-amine) can be directly attached to glass surfaces (Scheme 8). However, the amount of poly(amido-amine) grafted by this method appears to be much smaller than in the previous cases. 

---