تغییر مورفولوژی بسترهای سیلیکایی مزومتخلخل اس بی ای- 15 میله‌ای به بشقابی با استفاده از عنصر زیرکونیوم

Lipases find great use in a broad number of biotechnology fields, especially dairy, detergents, drugs (ibuprofen, naproxen), chemicals, agriculture (pesticides, insecticides) and oil chemistry (the hydrolysis of fats and oils).�In order to increase the half-life of the enzyme and repeated use of it, in this study the immobilization of lipase on the mesoporous silica SBA-15 has been investigated. For the first time, the effect of shortening rod channels on the adsorption capacity of porcine pancreatic lipase (PPL) has been studied. Due to the slowly diffusion of large lipase molecules, in addition to increase surface area by expanding the pore diameter, shortening of mesochannels can be considered as an effective parameter on the adsorption properties. Triblock copolymer Pluronic P123 and tetraethyl orthosilicate (TEOS) were used as structure directing agent and silica source in acidic media respectively. Tetramethylbenzidine (TMB) was used as a swelling agent for expanding pore diameter up to 10 nm. The well-ordered 2D hexagonal pore structure was obtained after prehydrolyzing silica for about 30 minutes. Shortening of rod mesochannels from 800nm to 100nm was also maintained in the presence of small amount of ZrOCl2.8H2O. Structural analysis by low angle XRD, nitrogen adsorption, scanning electron microscopy (SEM), high resolution transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy confirmed tuning effect of Zr in SBA-15 materials. The amount of lipases adsorbed on the mesoporous SBA-15 was determined by thermal gravimetric analysis. By optimizing synthesis parameters, the uptake capacity of PPL into the mesoporous silica was remarkably increased from 473.2 mg/g to 783.9 mg/g. �