Sharif Digital Repository

In this research a copper- diamond nanocomposite coating prepared by electrodeposition from a sulfate bath in order to increase the hardness and erosion resistance of cooper without disturbing cooper's specific physical properties as like as electrical and thermal conductivity. The mechanism of electrodeposition was analyzed with the technique of Cyclic Voltammetry, Chronopotentiometry and Chronoamperometry. The morphology, hardness, scratch resistance, elastic modulus and friction factor of coating were investigated by using a scanning electron microscope (SEM) and atomic force microscope(AFM) also the mechanism of co- deposition of diamond particles with copper was corresponded with... 

At the first part of this thesis, a pyrolitic graphite electrode (PGE) modified with graphite/nanodiamond film (GND) was applied as a sensitive electrochemical sensor for determination and study of electrochemical behavior of tryptophan (Trp) and 5-hydroxytryptophan (5-HTP) in aqueous solutions. The results showed that GND caused a remarkable increase in the peak currents so the GND/PGE electrode surface was more sensitive to the concentration of Trp and 5-HTP than the PGE surface. The determination of Trp and 5-HTP were investigated by stripping voltammetry. Experimental parameters such as scan rate, pH, accumulation conditions and amount of the modifier used on the PGE surface were... 

Nanotechnology inrecent yearshas attractedthe attention of manyscientists and industrialists. Having atiny structure with extraordinary properties of nanoparticlesin the fields of electrical, mechanical and thermal, leading to their use isgrowing and newer application sarebeing found forth eseparticles. One of them Nanodiamond powderiswidely usedin the industryhas found wideapplication. Among these can be used in electrochemistry, chemical coatings, pastesand suspensions, add thepolymer, ceramic and industrial rubber and adhesives,adsorbentsand catalysts, filters and membranes, and finally cancer treat mentnoted. One of these applicationsisinPolymers and Rubber Industry. According to earlier... 

Vulcanization is one the most crucial process in elastomer manufacturing products. It has been shown that network structure and curing kinetic are strongly dependent on curing system formulation. In addition reinforcing fillers in elastomers can affect them as well. By commencement of nanofillers in rubber domain, effects of nanofiller presence on rubber behavior have been investigated by reaserchers.
In this Project the effect of different curing system formulations on vulcanization kinetic and network structure of NR/SBR elastomeric matrice filled by nanodiamond is investigated. Different ingredients and nanodiamond were added to matrix by mechanical mixing in two roll mill. The... 

Present study demonstrated carbon nanoparticles/acrylate-terminated polyurethane composites as promising materials for bone implants applications. Neat polymer and composites containing nanoparticles at different loadings up to 2 wt % were prepared by in situ polymerization method. Morphological analysis exhibited that nanoparticles caused considerable phase separation between soft and hard domains as well as increased crystallinity. Mechanical analysis showed a significant improvement in mechanical properties. Maximum improvement in tensile properties of APUA was observed at 1 wt% loading of ND-HEAMs, namely 175% improvement in modulus. In vitro biocompatibility evaluation via culturing... 

In the first part, metallic nanoparticles were synthesized on the different carbon nanostructers platform such as nanodiamond and graphene sheet using electrochemical and chemical methods. The prepared composite film were characterized by electron microscopy, spectroscopy and electrochemical techniques. The synthesized nanocomposite were applied as a modifier in order to prepare electrochemical sensors for determination trace amount of important pharmaceutical and biological compounds.In the first work, Nanodiamond-graphite (NDG) decorated with Ag nanoparticles (AgNPs-NDG) was synthesized with chemical method. The surface morphology and the nature of the composite were investigated. The... 

Recently nanodiamond has drawn a vast attention of researchers due to exceptional mechanical properties. However, nanodiamond tendency to aggregation in polymer matrix restricts its reinforcement properties. In this research, novolac phenolic resin nanocomposites reinforced by nanodiamond were prepared by solution blending method and their mechanical properties were investigated. In order to prevent nanodiamond aggregation, ultrasonic treatment was used and nanodiamond surface was modified with acid and amine functional groups. FTIR and TGA were performed in order to investigate nanodiamond surface and confirmation of existence of acid carboxylic and oleylamine (OLA) groups. Produced... 

Polyamide or Nylon, due to its remarkable mechanical and tribological properties, has many engineering applications. Hence, improving the properties can develop the polyamide applications. In this study, Polyamide 6 (PA6) has been used as matrix with nanodiamond (ND) reinforcement. Spherical shape, chemically active surface as well as remarkable mechanical properties make nanodiamond an ideal candidate for improving polymers properties. Poor dispersion and agglomeration are present however major problems in achieving improved properties in nanocomposites. To deal with this problem, nanodiamonds were surface modified using Ethylenediamine (EDA) and Hexamethylenediamine (HMD). Nanocomposite... 

Polydimethylsiloxane (PDMS) is one of the most important organosilicon elastomers. This polymer has a wide application such as medical engineering due to the unique characteristics, variety and ease of manufacture. Nowadays, the use of nanoparticles such as carbon nanotubes for improving the properties of elastomers is highly regarded owing to the fact that the improvement of properties such as mechanical properties broadens the applications of PDMS. Diamond nanoparticles has been the focus of numerous researchers in the past decade. In fact, nanodiamond has a good mechanical abrasion and thermal properties. In addition, the investigations proved that the nanoparticle is valuable in terms of... 

Chitosan is a biocompatible and biopolymer with unique characteristics. Nanodiamonds that are basically carbon based nanoparticle have excellent mechanical, thermal stability biocompatibility bahviors. Combination of these two materials helps to the advantage of all the desirable features of both material and compensate low mechanical properties and strength of chitosan. In this study, we examine the composition of different percentages of nanodiamonds in chitosan and effect of modification on properties of the nanocomposites. The thermal behaviour, swelling behaviour and water contact angle of different nanocomposites were analyzed. Finally, to determine the distribution of the... 

In recent decades, nano-structured materials have been allocated specific position for wide use in various fields. The nano-diamonds has attracted the attention of many researchers. The inherent characteristics of a diamond like spherical structure of nanoparticles and carbon atoms which have used their full capacity in the chemical bonds,also the same surface as the radiography particles which have empty orbital, provides an ability to perform a variety of surface modification on the particle . This article introduces the nanocomposites based on polymer, constituents specification and discuss properties of nanocomposites after mixing components together. Lots of studies was on... 

Polymer composites, due to its exclusive properties, has a special place in industry. Epoxy resin with high adhesion property, low density, thermal stability and high chemical resistance has a special place as matrix in fabrication of high technology hybrid composites. Hybrid composites, due to its high strength and long fatigue life, used to reinforcing building structures and manufacturing fuselage. Layer and reactive structure near the firm core and wear-resistant of NDs, used to improvement of epoxy reisn and hybrid NanoComposite interphase properties. In this study, for improvement of the properties of hybrid NanoComposites, used the NDs in 0.25, 0.5 and 1 %wt with amine and carboxyl... 

The nucleus pulposus, which is a part of intervertebral disc, is normally hydrated and gel-like to maintain normal biomechanical functions of the disc through intradiscal pressures. In a degenerated disc, however, water content of nucleus is significantly reduced, resulting in an abnormal stress state of the annulus. Surgical interventions cannot restore the biomedical function to vertebral segment. One approach to restore the normal biomechanics of an intervertebral disc is to replace the nucleus with a prosthetic material which leads to a restoration of the behavior of the disc. The mechanical behavior of poly(vinyl alcohol) and nanodiamond hydrogel may provide a material suitable for... 

Ethylene vinyl acetate copolymer produces flexible products and is compatible with many polymers and additives, the reason is that it has Vinyl group which is polar and Ethylene group which is nonpolar. In fact, it consists of two parts. One is a hard and semi-crystalline Polyethylene region and the other is soft, flexible, polar, and amorphous Vinyl Acetate. Improving the properties of this copolymer can broaden its application. For this purpose, Ethylene Vinyl Acetate with 18 and 28% Vinyl Acetate was used as a matrix and nano-alumina as reinforcement in this project. The spherical structure and chemicallu active surface, along with significant mechanical properties, suggeats Alumina... 

Nanodiamond (ND)/polylactic acid (PLA) nanocomposites have the potential for biomedical applications and bone tissue engineering. In this research, nanodiamond/poly lactic acid nanocomposites were prepared by mechanical mixing solution method and applying ultrasonication. Also, PLA-based nanofiber scaffold reinforced by nanodiamond were prepared by electrospinning methods. To find the optimum value of parameters to prepare this nanocomposite sample, the effect of nanofiller concentration, mixing rate and duration, the role of solute and ultrasonication, and solvent evaporation conditions were investigated and then it compared to the neat polylactic acid sample. By means of Fourier transform... 

One of the ways that corrosion control is presented is the use of coatings that have good properties such as high adhesion, impact resistance, ultraviolet radiation, and so on. They also have other unique properties like anti-corrosion property. To achieve coatings with these advanced properties, they use special properties of nanocomposites. Nanocomposites can add or improve one or more properties to coating properties.In the present study, we tried to first synthesize NanoDiamond/Polyaniline hybrid nanoparticles in different percentages and then use this hybrid in epoxy ester coating. To characterize this hybrid, various analyzes such as FE-SEM, TEM, FT-IR, UV-Visible, TGA and XRD were... 

Polyvinylidene fluoride (PVDF) is remarkable since its mechanical properties, chemical stability and significant ferroelectricity. This Polymer has a simple chemical structure and can be found in five different crystal phases (α,β ,ɣ,δ and ε). Between these phases, beta shows a substantial pyro and piezoelectric activity since its great dipole moment. In this study PVDF/Poly(vinyl acetate)/Nanodiamond (ND) nanocomposite films were synthetized by solving in dimethylformamide adding ND particles to PVDF/PVAc blend in order to improve mechanical and piezoelectric properties. Scanning electron microscopy results showed that PVDF/PVAc are miscible and lead to a single crystal phase and dispersion... 

In recent years, nanodiamond (ND) has been used as reinforcement in polymeric nanocomposites in order to improve mechanical properties, thermal conductivity, etc. The surface of nanodiamond has several functional groups which make it appropriate adsorbent. In this study, nanodiamond was modified with dodecylamine corrosion inhibitor and was utilized (1wt %) in epoxy based nanocomposite. Fourier transform infrared spectroscopy (FTIR) analysis was used to confirm the surface modification of Nanodiamond. In order to estimate the loading amount of corrosion inhibitor, thermogravimetric analysis was investigated. FE-SEM analysis demonstrated nanoparticle dispersibility in epoxy matrix. Regarding... 

Polyamide6 has many engineering applications due to its physical, mechanical and processability properties. However, its low impact resistance limits the use of polyamide6. One of the common ways to overcome this problem and extend the range of polyamide6 application is its elasticity with elastomeric materials, which reduces the strength and modulus (tensile and flexure) in comparision with neat polyamide6. To overcome this limitation, various reinforcements, often fiber or particle-shaped, are used. Today, with the development of nanoparticles, this effort is being made to use nanoparticles, especially carbon nanoparticles with unique properties. Recent research has shown that the addition... 

Flexible polymers (elastomers) are especially suitable for dynamic applications, and carbon fillers are well-known filler for elastomers. These are widely used in elastomer matrices for various commercial applications. Some of carbon nano fillers like Nano Diamond cannot impart such high degree of reinforcement to polymer matrices mainly because of improper filler dispersion and lack of strong filler-polymer interaction. In this effort, we examine the effects of two different nanostructured carbons when they are incorporated in a rubber matric in terms of mechanical, thermal and electrical properties of the nanocomposites. Different ingredients and hybrid nanofillers were added to matric by...