سنتز، شناسايي و بررسي خواص بيونانوكامپوزيت هاي فعال نوري پلي ﴿آميد-ايميد﴾ /تيتانيوم دي اكسيد جديد و اصلاح خاك رس توسط آمينو اسيدوالين براي تهيه بيونانوكامپوزيت هاي پلي ﴿وينيل الكل﴾/خاك رس اصلاح شده

چكيده انگليسي :

Synthesis Characterization and Properties of Novel PAI TiO2 Optically active BNCs and Modified Cloisite Na with L Valine Amino Acid for Preparation of PVA Cloisite Val BNCs Samira Moslemi s moslemi@ch iut ac ir Date of Submission 2011 3 9 Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Shadpour Mallakpou Mallak@cc iut ac ir Abstract In this thesis a new optically active poly amide imide PAI was synthesized by the indirect polycondensation reaction of the L phenylalanine based diacid chloride and 4 4 diaminodiphenylether in the presence of triethylamine in N methyl 2 pyrrolidone The formation of PAI was confirmed by FTIR 1H NMR and elemental analysis In next step the surface of titanium dioxide TiO2 nanoparticles was treated with a silane coupling agent of aminopropyl triethoxy silane KH550 TiO2 is one of the most potential materials nontoxicity and chemical inertness that cause wide applications in the fields of electronic and photonic TiO2 has three crystalline polymorphs rutile anatase and brookite The most common form of bare TiO2 crystal that used in many industries such as paints and cosmetics is rutile that stable at high temperatures The anatase to rutile transition is an irreversible procedure and usually generated within a temperature range of 500 1000oC TiO2 nanocomposites have many applications especially in medicine cleaning machining jointing and chemistry industry Other application fields of them are ultraviolet light absorbent coating interference filter antireflective coating and optical waveguides Then PAI and surface modified TiO2 nanoparticles were used to produce a polymer based bionanocomposites BNC s via ultrasonic irradiation process Obtained BNCs were characterized by means of fourier transformation infrared spectroscopy X ray diffraction thermogravimetric analysis TGA scanning electron microscopy SEM field emission scanning electron microscopy and transmission electron microscopy TEM The results obtained from TEM and SEM micrographs showed that the nanoparticles are homogeneously dispersed in PAI matrix on 30 50 nm TGA analysis of the PAI TiO2 BNCs shows the great improvement in thermal stability parameter of the BNCs related to pure PAI Cloisite Na as a kind of MMT is a hydrous alumina silicate mineral that made from octahedral alumina sheet between two tetrahedral silicate sheets and ions holding between the layers It shows a net negative charge on the lamellar surface Surface properties of natural clays can be modified by simple ion exchange process with organic cations such as quaternary ammonium cations During of this modification the clay changes from hydrophilic to hydrophobic as well as organophilic and is converted to an organoclay The inorganic nanolayers of Cloisite Na was modified with ammonium salt of L valine amino acid Val and then it was dispersed in poly vinyl alcohol PVA matrix PVA is a synthetic nontoxic tasteless biocompatible water solubility and semicrystalline hydrophilic polymer The PVA Cloisite Na Val bionanocomposites BNC s were prepared by solution intercalation technique using ultrasonic irradiation The reaction between this novel organically modified Cloisite Na and PVA occurred by the hydrogen bonding and hydrophobic interactions The basal spacing of the Cloisite Na Val was studied by X ray diffraction The thermal stability and optical clarity of PVA and PVA Cloisite Na Val are also studied by TGA and UV visible transmission spectra respectively TGA results show that using Cloisite Na Val in the PVA matrix improved the thermal stability property of the resulting BNC films The morphological image of synthesized materials was studied by scanning electron microscopy and transmission electron microscopy The nanocomposite structure study specified a coexistence of exfoliated and intercalated Cloisite Na Val layers in the PVA matrix Keywords Optically active polymer Bionanocomposite Poly amide imide TiO2 n

مسلمي، سميرا

Tio2 , معرف اصلاح كننده , پايداري حرارتي , زيست تخريب پذيري