Papers by Keyword: 3-Aminopropyl Triethoxysilane

Abstract: Bioglass (BG) particles were treated by 3-aminopropyltriethoxysilane (APTES) in order to improve the interface compatibility with polymer materials. The surface structures of modified BG were characterized through Fourier transformed infrared spectroscopy with attenuated total reflectance accessory, thermogravimetric analysis, differential scanning calorimetry analysis and X-ray photoelectron spectroscopy. The results showed that APTES was successfully grafted on the surface of BG. The biomineralization properties of APTES modified bioglass were also studied through FTIR, XRD and SEM. Results showed that hydroxylcarbonateapatite (HCA) was formed on the surface of modified BG after soaked into SBF solution. It was shown that the APTES modified BG could possess good mineralization properties and could be intended as a composition of scaffolds for bone tissue engineering applications.

Abstract: OH groups on hydroxyapatite (HA) and calcium metaphosphate (CMP) were evaluated by grafting tetraethyl orthosilicate (TEOS) and 3-aminopropyltriethyloxysilane (3-APTES) which can bond covalently with OH group of ceramic biomaterials. The prepared HA and CMP disks were soaked in pH 2 and 5 of acidic water and ethanol solution respectively, where pH change of each solution was measured during soaking of samples. After grafting TEOS and 3-APTES on HA and CMP disks, samples were ultrasonically cleaned in distilled water and soaked in pH 5 of ethanol solution, and pH measurement was carried out in the same manner. The pH value of HA and CMP in aqueous solution at pH 2 increased with time continuously, resulting from dissolution of HA and CMP by acidic condition on surface. At pH 5 in aqueous solution, it was the same though the pH increase was smaller. In case of ethanol at pH 5 with HA, though pH value went up slightly, the curve became saturated with time, while there was no change in pH with CMP. After grafting TEOS and 3-APTES, pH values were stabilized with few changes, indicating that there was no direct chemical reaction between the acidic media and the surface of samples due to covalently grafted TEOS and 3-APTES layer. In conclusion, it was confirmed that OH group on the surface of HA was crystallographic and chemical one rather than physically adsorbed one by grafting TEOS or 3-APTES and it will serve an effective binding site for calcium and phosphate ions, or minerals.

Abstract: A study was conducted on the effects of surface pre-treatment with 3- aminopropyltriethoxysilane (3-APS) on the water absorption and adhesion behaviour of two commercial alkyd and epoxy polyamide organic coatings on mild steel and glass substrates. The results indicated that using 3-APS as surface pre-treatment prior to coating resulted in a significant reduction of total water absorption for alkyd on both mild steel and glass substrate. Subsequently ile adhesion of alkyd is enhanced on both pre-treated mild steel and glass substrate. However 3-APS pre-treatment of mild steel increases water absorption of epoxy and lowers its adhesion strength. While 3-APS pre-treatment of glass reduces water absorption of epoxy and subsequently enhances the overall wet adhesion. These data are consistent with the known adsorption behaviour of 3-APS to steel, i.e. as an easily hydrolysed hydrogen-bond to the amine group, rather than as the more stable metal-oxide-silicon bond.

Abstract: Organically-modified silica xerogels from 3-aminopropyltrimethoxysilane (APTES) and 3-isocyanatepropyltriethoxysilane (ICPTES) have been synthesized through carboxylic acid (formic acid, acetic acid and valeric acid) solvolysis. The resulting hybrid materials have been characterized by powder X-ray diffraction, mid-infrared spectroscopy, 29Si and 13C nuclear magnetic resonance, and photoluminescence spectroscopy. The results show that urea cross-links have been formed in these hybrids. The luminescence features depend on the selected carboxylic acids. For example, comparatively to the hybrids derived from formic and acetic acid solvolysis, valeric acid shows a red-shift of the emission features.