تهيه و بررسي غشاي لايه نازك پلي آميد - نانو نقره با كارايي مطلوب جهت كاربرد در فرآيند اسمز معكوس

چكيده انگليسي :

Preparation and Charachterization of Polyamide Nanosilver Thin Film Membrane with Suitable Reverse Osmosis Performanc Mohammad Khalil Bahmanpour Mk bahmanpoor@ce iut ac ir Date of Submission 2012 02 29 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisors Mahmood Masoomi mmasoomi@cc iut ac ir Ahmad Moheb ahmad@cc iut ac irAbstractMembrane degradation due to biofouling is one of the main obstructions for aromatic polyamide thin filmcomposite TFC reverse osmosis RO membranes to realize high performance over a long period ofoperation In this study thin film nanocomposite TFN membranes consisted of silver nano particles as theanti bacterial material and poly vinyl pyrrolidone as the hydrophilic polymer with antibacterial ability wasdevised as a novel means to mitigate membrane biofouling The sliver nanoparticles were synthesized bysonochemical method by applying ultrasonic irradiation to the aqueous solutions of sliver nitrate as theprecursor silver colloids meta phenylene diamine monomer as reducing agents and poly vinyl pyrrolidone powder as stabilizer The effects of the synthesis conditions such as molar ratio time and temperaturereduction on the size and shape of the particles were also studied Formation and size of the silvernanoparticles were investigated by using UV Visible spectroscopy and Atomic Force Microscopicmethods The results showed that average particle size of the silver particles varied between 55 to 520 nm The smallest particles were obtained from a synthesis solution initially contained 0 4 w v nitrate silver 2 w v meta phenylene diamine 1 85 w v poly vinyl pyrrolidone which was reduced at 10 C for15min The thin film nanocomposite membranes were prepared via in situ interfacial polymerization oftrimesoyl chloride 0 2 w v in the hexane solvent and colloidal silver solution over porous polysulfonemicro filtration supports Attenuated total reflectance mode Fourier transform infrared ATR FTIR spectroscopy showed that the thin film nanocomposite membrane had three characteristic bands at 1541 1602 and 1649 cm 1 corresponding to amide and carbonyl groups in polyamide This result suggested thatthe thin film nanocomposite membranes were synthesized in the presence of nano silver and poly vinylpyrrolidone The top surface morphology of thin film composite and silver polyamide membranes wasanalyzed by scanning electron microscopy SEM Comparison between the SEM images of the surfacemorphology of thin film composite and thin film nanocomposite membranes showed the thin filmcomposite membrane had dense structure However the top surface morphology of thin film nanocompositemembrane is changed to open pore morphology by adding silver nanoparticles and poly vinyl pyrrolidone to the aqueous phase during synthesis process of the membranes The EDX spectrum for thin filmnanocomposite membrane showed elemental silver peak confirming the presence of the silver element inthe thin film nanocomposite membrane The reverse osmosis performance of membranes exhibited thatwater permeation flux increased from 12 l m2h for thin film composite membrane to 15 l m2h for thinfilm nanocomposite membrane Also salt rejection of thin film composite membrane decreased from 89 to 84 compared to thin film nanocomposite membrane Finally the results of measuring the thin filmnanocomposite membrane resistance against the E coli bacteria cell showed that the 75 of the bacteriawere destroyed which was much higher than 9 for thin film composite Also thin film nanocompositemembranes proved to have more resistant against biofouling Keywords Nanosilver interfacial polymerization polyamide reverse osmosis membrane antibacterial biofouling

بهمن پور، محمد خليل

تهيه و بررسي غشاي لايه نازك پلي آميد - نانو نقره با كارايي مطلوب جهت كاربرد در فرآيند اسمز معكوس

نانو ذرات نقره , پليمريزاسيون بين سطحي