چكيده به لاتين
In this study, a Graphene oxide (GO) modified dextrin nanocomposite was fabricated in main three steps as polymer nanocomposite consists of dextrin as polymeric matrix and GO as nanofiller. In this regard, dextrin functionalized with 3-minopropyltriethoxysilane (APTES). Next GO was prepared by hummer method, then in third step it was activated by pichlorohydrin (ECH) and reacted with APTES@dextrin. The prepared nanocomposite was well characterization by different techniques such as FT-IR, EDX, SEM, XRD, TGA, and AFM. Due to the remarkable properties of this nanocomposite (which is originated from the properties of polymer matrix and nanoparticles of graphene oxide) such as high surface area, high stability, possessing a great number of reactive functional groups and high biocompatibility, its application in two different fields was investigated; the first as an adsorbent of environmental pollutants including chlorpyrifos pesticide and Congo red dye from aqueous solutions and the second as a heterogeneous organocatalyst for the synthesis of pyrazolopyridine derivatives via one-pot multicomponent reaction (MCR). The result showed that this polymer nanocomposite can effectively absorb the desired pollutants from aqueous solution, and the influence of the pH of the solution, adsorbent dosage, contact time, initial concentration of pollutants on adsorption capacity was evaluated. The Isotherm and kinetic studies revealed that the experimental adsorption data described well by the Langmuir isotherm model and the maximum adsorption capacity (Qmax) of prepared the sorbent for chlorpyrifos and Congo red was found 582.2 and 557.74mg/g, respectively. The adsorption kinetic data were well fitted by the pseudo-second-order model for both contaminants. The prepared nanocomposite exhibited excellent catalytic activity in the synthesis of dihydropyrano[2,3-c]pyrazole derivatives with mild reaction conditions, relatively short reaction condition (15-35 min) and high yields products(90-98) without complicated purification procedure.
