Programme Book - UPM - Universiti Putra Malaysia

P45 PREPARATION AND CHARACTERISATION OF SILVERNANOPARTICLES IN CHITOSAN VIA ULTRASONIC METHODS.N. Rafidah, M. Ahmad*Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPMSerdang, Selangor, MalaysiaCorresponding author: mansorahmad@upm.edu.mySilver nanoparticles (Ag-NPs) were synthesized via sonochemical method, a greenprocess, and with chitosan (Cts) as the stabilizing agent. The effects of fourparameters were investigated, namely; ultrasonic time, ultrasonic speed, silver nitrate(AgNO 3 ) and Cts concentrations. Characterizations of Ag-NPs were done usingPowder X-ray Diffraction (PXRD), Transmission Electron Microscopy (TEM), UVvisibleSpectroscopy, Fourier Transform Infrared (FT-IR) and Atomic ForceMicroscopy (AFM). The aim of this research is to investigate the conditions andtechniques to obtain Ag-NPs with uniform size by using ultrasonic method and toattain nanoparticles with a smaller size and with a narrower distribution. Ag-NPs wereprepared from AgNO 3 and Cts using ultrasonicator device. Firstly, Cts were dissolvedin 100 mL distilled water together with the addition of 2.0 mL acetic acid, (HAC)with continuous stirring. In the intervening time, AgNO 3 was dissolved in 20 mLdistilled water separately. After dissolving, both the solutions were mixedhomogenously and ultrasonicated. This results in the production of Ag-NPs. The mostfavourable experimental condition for the synthesis of Ag-NPs in the Cts is describedin terms of the concentrations of AgNO 3 . The mean diameters and standard deviationof Ag-NPs decreased gradually with the increase of silver ions concentration. The Ag-NPs by the physical synthetic route were synthesized in the Cts using the ultrasonicmethod in the absence of reducing agent or heat treatment. The properties of Ag/Ctswere studied as the function of ultrasonic irradiation times. Ultrasonic irradiationdisintegrated the Ag-NPs into smaller size until a relatively stable size and sizedistribution were achieved. The results from the UV-visible spectroscopy and TEMdemonstrated by increasing the ultrasonic irradiation time, it decreases the size of Ag-NPs. Upon increasing the Cts concentration, the intensity however has increasedremarkably rendering higher yields of Ag-NPs. Furthermore, it can be seen that thesmaller Ag-NPs were obtained under ultrasonic irradiation with higher amplitudebecause the SPR of Ag-NPs displays the blue shift with decreasing particle size. TheAgNO 3 and Cts were used as the silver precursor, natural and biodegradablepolymeric stabilizer respectively. The XRD analysis confirmed that thecrystallographic planes of the silver crystals were the face centered cubic (fcc) types.The UV-visible absorption spectra showed the peaks characteristic of the SPR bondsof Ag-NPs. Results shows that the ultrasonic irradiation time, ultrasonic amplitude,concentration of Cts and AgNO 3 concentration are the main effective factors informing the size and yield of Ag-NPs.60 |16 th Industrial Chemistry Seminar: Chemistry- A Passport to a Brighter Future