Synthesis, Ultra-Microscopic and Comparative Studies of Silver and Nickel Nanoparticles

Silver and nickel nanoparticles were synthesized from urea and formaldehyde by using chemical method, followed by calcination at 8000C. The chemical composition and crystallographic structure of silver and nickel nanoparticles were conrmed by XRD. Surface imaging studies like AFM was carried out for estimating surface morphology and particles size distribution. The spherical and porous like morphology of silver and nickel nanoparticles conrmed by SEM and TEM. White spots are observed in the presence of silver and nickel metal ions in spherical forms. The particles size of silver and Nickel metal ions were found to be obtained through XRD 41.43 nm and 13.71 nm respectively.


Introduction
Polymer materials are widely used in industry due to their ease of production, lightweight and ductile nature. A very effective approach to improve mechanical properties is to add bres, whiskers, platelets or particles as reinforcements to the polymer matrix. The polymer nanoparticles show enhanced properties by the incorporation of low amount of Nano llers such as carbon black (CB), carbon nanotubes(CNTs), graphene and Nano clay (Huang, 2002, Moniruzzaman et al. 2006, Kim et al. 2010, Fischer, 2003. Polymers have been lled with several inorganic compounds, either synthetic or natural, in order to increase heat and impact resistance, ame retardancy and mechanical strength, and to decrease electrical conductivity and gas permeability with respect to oxygen and water vapor (Hajji et al. 1999).
Such composites are widely used in many areas like in electronics, catalysis, transportations and construction, because of their novel properties. Compared to conventional composite nanoparticles, these have ultra ne nanometer size phase dimensions and offer unique combination of properties due to the size (Sanchez et al. 2000, Sanchez et al. 1999, Pomogilo,2000, Novak,1993, Lichtenha et al. 2001, Sanchez et al. 1994, Ells et al. 1999, Kwiatko et al. 2000, Schubert et al. 1995, Mori Kawa et al. 1992, Giannelis et al. 1999, Jordan et al. 2005. Following these approaches, polymers can be improved while keeping their lightweight and ductile nature (Akita et al. 1999, Chang et al. 2002, Zavyalov et al. 2002. Another important aspect of nanoscale reinforcements is that it has exceptional potential to generate new phenomena, which give special properties in these materials. Urea-Formaldehyde (UF) resin is widely used as thermosetting materials due to low cost and good thermal and mechanical properties including chemical resistance. This resin is the condensation product of urea and formaldehyde. Most thermosetting resins like UF are used with reinforcing llers or bres to produce composite materials for use in a wide range of commodity, engineering and other special applications. Several preparative methods of composite particles of polymer and magnetite particles are proposed ) like suspension polymerization (Horak et al. 2010) dispersion polymerization (Pimpha et al. 2015) emulsion polymerization (Wang et al. 2005) soap-free emulsion polymerization (Mori et al. 2007) mini emulsion polymerization (Liu et al. 2003) and micro emulsion polymerization . Above these methods involve for nanoparticles formations require high temperature and expensive instruments. One of the simplest and cost effective techniques to prepare the silver and nickel nanoparticles is by thermal decomposition. This technique has various advantages over other method which include easy handling reaction and short reaction time for the preparation of different type of nanoparticles (Traversa et al. 1998, Farhadi et al. 2010. The objective of this study to synthesized. silver and nickel nanoparticle is performed by using urea and formaldehyde resin as precursor. with thermal decomposition method. The synthesized nanoparticles have been characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM).

Material And Methods
Silver nitrate (AgNO 3 ), Nickel Chloride Hexahydrate (NiCl 2 .6H 2 O), Formaldehyde (HCHO) and Urea (NH 2 CONH 2 ) were purchased from central drug House Pvt. Ltd. and Sodium Hydroxide (NaOH), hydrochloride Acid (HCl) was Purchased from sher scienti c. All solvent was of analytical reagent grade and water used without further puri cation for the preparation of metal solutions.
Silver and Nickel nanoparticle was synthesized by following methods-A. Formation of polymer metal complex B. Formation of silver/ nickel nanoparticle (A) Formation of Polymer metal complex 1.38 mole of urea, 1.13 moles of formaldehyde and 15 ml glacial acetic acid add in three necked round bottom ask equipped with re ux condenser and stirrer. The mixture was agitated and was allowed cool off. Water was removed by slowly raising the temperature to 60 0 Cand applying a vacuum by means of water pump. This temperature was maintained till the melting of sample which on cooling solidi es into a white colored solid. Then add 15 ml of silver nad nickel metal solution was added to prepare polymer metal complex respectively. The reaction is exothermic in nature. The dried solid sample was puri ed by the washing with distilled water.
(B) Formation of silver and nickel nanoparticles: The polymer metal complex calcinated at 800 0 C for 45 minutes in mu e furnace. Black colored silver and nickel nanoparticles were obtained (Chaudhary et al. , 2018.
Puri cation of silver and nickel nanoparticles: Metallic ions were removed from the nanoparticle by keeping it in 12N hydrochloric acid solution for 24 hours. The mixture was centrifuged and washed with distilled water till hydrochloric acid was completely removed (Chaudhary et al. 2018). The volatile impurities got separated at time of calcinations.   particles and white part is polymer matrix. Thus, SNPs were recorded to be globular and rod like whereas nickel nano particles were of granular morphology. X-ray Diffraction (XRD) Analysis:     The present study supports the ndings of (Kotakadi et al. 2013) who have also made the similar observations that AgNPs have a spherical shape and the diameters of AgNPs varied between 27 and 50 nm. Similarly, (Muzamil et al. 2014) have also recorded that particles are nearly spherical identical in shape, dispersive & crystalline in structure Conclusion:

Result And Discussion
Silver and nickel nanoparticles synthesized by chemical precipitation method followed by thermal decomposition. The morphology studies by SEM show that the silver nanoparticles are spherical and nickel nanoparticles have pore-like shapes like that of carbon-black. The particle size determined by XRD and surface to volume area results of AFM studies also indicate the exact structure and probable properties of the synthesized nanoparticles. Our results are good indicative of the e cacy of the chemical precipitation method in the synthesis of the nanoparticles. In future, these Silver Nano Particles can be further analyzed for its heat transfer properties and application in nano uids and conductive gels. We will further investigate the catalytic activity of nickel nanoparticles.   Scheme 1. Reaction for the nickel and silver nanoparticle