ABSTRACT
Nanoscience has been set up recently as a new interdisciplinary science with potential application in medicine, cosmetics, renewable energies, environmental remediation, agriculture among others. Even in the usefulness of nanoscience, a lot of chemicals are used for its production which pose a potential threat to the environment and public health. Thus, the importance of green synthesis. The aim of this study is to synthesize silver nanoparticles AgNPs using Vernonia amygdalina as a reducing and capping agent in various solvents; distilled water, ethanol and methanol. With the range AgNPs being between 1-100nm, the major goal was to determine the degree of reduction of the silver ions (Ag+) to metallic
nanosilver (Ag0) in all the sample extracts. The laboratory experiment was carried out to
produce the solvent extracts which were used as reducing and capping agents on AgNO3 to synthesize AgNPs of ethanol, methanol and water extract. Characterization in UV- Vis Spectroscopy showed that Surface Plasmon Resonance (SPR) in 414nm, 406nm and 306nm for ethanol, methanol and water extracted AgNPs respectively. FTIR showed the possible presence of AgNPs in ethanol, methanol and water extracted AgNPs at 669.09, 669.38 and 616.17 cm-1 respectively. The Scanning Electron Microscopy (SEM) showed that ethanol,
methanol and water extracted AgNPs had values of 335nm, 584nm and 460nm respectively. The morphologies were also obtained as follows; ethanol extracted AgNPs had spherical shaped particles, water extracted AgNPs had thread-like particles and methanol extracted AgNPs had crystal-like particles. Thus, it is safe to say that Vernonia amygdalina extracts has the potential of reducing Ag+ to Ag0.
CHAPTER ONE
Introduction
1.0 Background of the Study
The concept of nanotechnology though considered a modern science has its history dating
back to the 9th century. Nanoparticles of gold and silver were used by the artisans of
Mesopotamia to generate a glittering effect on pots. The first scientific description of
nanoparticles was provided by Michael Faraday in 1957 in his famous paper “Experimental
Relations of Gold (and other metals) to Light” as deduced from the paper Faraday, (1957).
Ahmed et al, (2003) the first time the idea of nanotechnology was introduced was in 1959,
when Richard Feynman, a physicist at Caltech, gave a talk called “There’s Plenty of Room at
the Bottom.” Though he never explicitly mentioned “nanotechnology,” Feynman suggested
that it will eventually be possible to precisely manipulate atoms and molecules. Moreover, in
an even more radical proposition, he thought that, in principle, it was possible to create
“nano-scale” machines, through a cascade of billions of factories. According to the physicist,
these factories would be progressively smaller scaled versions of machine hands and tools.
He proposed that these tiny “machine shops” would then eventually be able to create billions
of tinier factories. In these speculations, Balaji et al, (2009) also suggested that there are
various factors, which uniquely affect the nano-scale level. Specifically, he suggested that as
the scale got smaller and smaller, gravity would become more negligible, while both Van Der
Waals attraction and surface tension would become very important. In the end, Feynman’s
talk has been viewed as the first academic talk that dealt with a main tenet of nanotechnology, the direct manipulation of individual atoms.
The 1950’s and the 1960’s saw the world turning its focus towards the use of nanoparticles in
the field of drug delivery. One of the pioneers in this field was Professor Peter Paul Speiser.
His research group at first investigated polyacrylic beads for oral administration, and then
focused on microcapsules and in the late 1960’s developed the first nanoparticles for drug
delivery purposes and for vaccines. This was followed by much advancement in developing
systems for drug delivery (e.g.) the development of systems using nanoparticles for the
transport of drugs across the blood brain barrier. In Japan, Sugibayashi et al, (1977) bound 5-
flourouracil to the albumin nanoparticles and found denaturation temperature dependent
differences in drug release as well as in the body distribution in mice after intravenous tail vein injection.
In 1979, Eric Drexler encountered Feynman’s talk on atomic manipulation and “nano-
factories.” The Caltech physicist’s ideas inspired Drexler to put these concepts into motion by
expanding Feynman’s vision of molecular manufacturing with contemporary developments in
understanding protein function. From that moment, Drexler’s primary goal was to build upon
the physicist’s revolutionary foundation. As a result, though the term was yet to be coined, the
field of nanotechnology was created ( Fanfair, et al., 2007). The nano-revolution conceptually
started in the early 1989’s with the first paper on nanotechnology being published in1981 by
K. Eric Dexler of Space Systems Laboratory, Massachusetts Institute of Technology. It was
titled “An Approach to the Development of General Capabilities for Molecular Manipulation.”
Although modern nanotechnology is quite new, nanoscale materials have been used for
centuries. Alternative-sized gold and silver particles created colours in the stained glass
windows of medieval churches years ago. The artists back then didn’t know that the process
they used to create these beautiful works of art actually led to changes in the composition of
the materials they were working with. Today, scientists and engineers are finding a wide
variety of ways to deliberately make materials at the nanoscale to take advantage of their
enhanced properties such as higher strength, lighter weight, increased control of light
spectrum and greater chemical reactivity than other materials on the macroscale and microscale
It is hard to imagine just how small nanoparticles are. One nanometer is a billionth of a meter or 10‾⁹ of a meter.
Some illustrative examples;
• There are 25,400,000 nanometers in an inch.
• A sheet of newspaper is about 100,000 nanometers thick.
• On a comparative scale, if a marble were a nanometer then one meter will be the size of the earth.
1.1 Statement of Problem
• The functions of individual atoms and molecules can be improved upon and
nanoscience poses to be the newest frontier in science that seeks to manipulate the
structure, sizes and functions of individual atoms and molecules which then
automatically affects their application. This research is intended to determine the
degree to which silver can be manipulated using Vernonia amygdalina as a reducing and capping agent.
• Also considering that other methods of synthesis of nanoparticles; chemical, physical
etc. are considered more toxic, in this work I will be performing the green synthesis which is less toxic and eco-friendly.
1.2 Aim
To synthesise of silver nanoparticles using leaf (Vernonia amygdalina) in selected solvents and it’s characterization by spectroscopic methods and scanning electron microscopy.
1.3 Objectives
• To determine the degree of reduction of silver ion (Ag+) to metallic nanosilver (Ag0).
• To determine the morphology of the sample formed
• To determine which of the solvent extractions will yield the best result.
1.4. Significance of the Study
The significance of this study is to benefit the science community by providing evidence
based conclusions on the ability of Vernonia amygdalina to facilitate the development and
activity of nanoparticles. Vernonia amygdalina was used because it is cost effective and its diverse health benefits.
DISCLAIMER: All project works, files and documents posted on this website, UniProjectTopics.com are the property/copyright of their respective owners. They are for research reference/guidance purposes only and some of the works may be crowd-sourced. Please don’t submit someone’s work as your own to avoid plagiarism and its consequences. Use it as a reference/citation/guidance purpose only and not copy the work word for word (verbatim). The paper should be used as a guide or framework for your own paper. The contents of this paper should be able to help you in generating new ideas and thoughts for your own study. UniProjectTopics.com is a repository of research works where works are uploaded for research guidance. Our aim of providing this work is to help you eradicate the stress of going from one school library to another in search of research materials. This is a legal service because all tertiary institutions permit their students to read previous works, projects, books, articles, journals or papers while developing their own works. This is where the need for literature review comes in. “What a good artist understands is that nothing comes from nowhere. All creative work builds on what came before. Nothing is completely original.” - Austin Kleon. The paid subscription on UniProjectTopics.com is a means by which the website is maintained to support Open Education. If you see your work posted here by any means, and you want it to be removed/credited, please contact us with the web address link to the work. We will reply to and honour every request. Please notice it may take up to 24 – 48 hours to process your request.
