A three dimensional integral equation is developed in order to compute water adsorption onto aggregates of spherical aerosol nano particles. The integral equation is derived from molecular density functional theory, with a weighted density approximation and a direct correlation function interpolation rule. Only required inputs are the direct correlation functions of the uniform fluid or gas at both high-density and low-density limits. The equation has been tested on argon adsorption onto a graphite planer substrate; the result corresponds well with previous simulation work. Adsorption of both noble gas and water onto a single spherical nano particle and aggregates of spherical nano particles has been computed with the developed equation. For the adsorption of a single spherical substrate, layer structure has been found, the adsorption shows a transition property when substrate size increases and when the substrate size is over 100?? the adsorption is nearly the same as that of a planer substrate. For adsorption of aggregates of spherical nano particles, not only much strong adsorption appears but also adsorption property changes with different configurations of spherical nano particles.

A three dimensional integral equation is developed in order to compute water adsorption onto aggregates of spherical aerosol nano particles. The integral equation is derived from molecular density functional theory, with a weighted density approximation and a direct correlation function interpolation rule. Only required inputs are the direct correlation functions of the uniform fluid or gas at both high-density and low-density limits. The equation has been tested on argon adsorption onto a graphite planer substrate; the result corresponds well with previous simulation work. Adsorption of both noble gas and water onto a single spherical nano particle and aggregates of spherical nano particles has been computed with the developed equation. For the adsorption of a single spherical substrate, layer structure has been found, the adsorption shows a transition property when substrate size increases and when the substrate size is over 100?? the adsorption is nearly the same as that of a planer substrate. For adsorption of aggregates of spherical nano particles, not only much strong adsorption appears but also adsorption property changes with different configurations of spherical nano particles.

The Li-oxygen cell is an emerging energy storage system which has a great promise in the near future for its high energy density and use of free oxygen available from the air. This energy system is attractive since it has nine times higher energy density than conventional lithium-ion cells based on LiCoO2 and graphite. However, this deceptively simple system poses many challenges which must be overcome before it could be considered for any practical application. Firstly, the formation of the insulating and insoluble reaction product, lithium peroxide, requires the highly porous, yet electronically well percolated cathode structure for the reasonable performance. Secondly, the decomposition of lithium peroxide usually involves the huge anodic overpotential which requires the development of highly efficient catalyst. Thirdly, a proper electrolyte system should be developed which is resistant to both the superoxide attack during the discharge reaction and the highly oxidizing environment during the charge process where both oxygen radicals and catalysts are present. Lastly, protection of the lithium anode is necessary, otherwise oxygen radicals in the solvent will react with lithium metal spontaneously, which eventually increases the impedance and more importantly depletes lithium metal from the anode. This thesis is primarily focused on the development of highly efficient catalysts for oxygen reduction and oxygen evolution reactions for the rechargeable Li-oxygen battery. To this end, a highly porous and electrically networked cathode film was manufactured by utilizing common plasticizers as pore forming agents and a Li-oxygen testing cells were developed using Swagelok??? fittings. The Li-oxygen cell test in two different electrolyte systems shows that the reactivity of electrolyte system to superoxide radicals is a key parameter to determine the nature of reaction product. For LiBOB/PC system, both LIBOB and PC are actively decomposed by superoxide radicals to produce lithium oxalate and lithium carbonate as main discharge products. In the case of LiPF6/TEGDME system, both salt and solvent are stable and thus ideal discharge product, lithium peroxide is obtained. Lead ruthenate and bismuth ruthenate with the extended pyrochlore structure show an excellent catalytic activity by increasing discharge capacity and lowering the anodic overpotential considerably during charge process in both electrolyte systems. They reduce the decomposition of electrolyte system and the extent of carbon corrosion, which accounts for more efficient cycling. The excellent catalytic activity of these pyrochlores originates from their intrinsic oxygen vacancies, electronic conductivity and many surface active sites afforded by its morphology. The performance of this catalyst was further increased through gold deposition on the pyrochlore surface, resulting in much increased discharge capacity. The pyrochlore coated carbon was proposed as a type of catalyst for an efficient way to reduce the amount of catalyst and enhance homogenous mixing with other components. The investigation on the lithium peroxide decomposition mechanism shows that carbon corrosion which occurs at around 4.0 V by lithium peroxide makes further decomposition difficult without a catalyst. In the presence of catalyst, almost full decomposition of lithium peroxide occurs with a lowered decomposition potential even though carbon corrosion still occurs. This gives a hint that the generation of a nano-porous structure and the homogenous distribution of catalyst over these pores are very important, as well as use of a highly efficient catalyst for lowering activation overpotentials. In conclusion, although there are still many obstacles present, as listed above, for the commercial application of Li-oxygen cell, these hurdles are surmountable in the near future by intensive research and the results shown in this thesis can be a cornerstone for further research. Supercapacitors based on metal oxide are new energy storage devices for ultrafast charging and discharging with decent energy density over hundreds of thousands of cycles for many commercial electronic devices and power tools. The surface redox nature of these reactions requires the creation of high surface area for better utilization and performance. Hydrous ruthenium dioxide is one of the most attractive supercapacitor materials owing to its high pseudo-capacitance and metallic character, which facilitate fast electron movement. In this thesis, a simple process involving soft liquid crystal templating using cationic surfactant and gentle heat-treatment in the mild temperature was developed to prepare mesoporous ruthenium oxide with a quasi-crystalline wall character, which has a high surface area and controlled water contents in the structure. The electrochemical testing results exhibited a promising performance of high gravimetric capacitance and a good rate capability facilitated by high surface area as well as porous structure.

Hygroscopic properties are important characteristics of a material that is used in building construction. Wood is an anisotropic, heterogeneous and hygroscopic material. Given the cellular structure of wood as well as capillary action in the Lumina, the level of water uptake in wood is significant. Such amount of water uptake makes the wood susceptible to dimensional instabilities, causes alterations in the mechanical properties, and potential for degradation of the material. Various approaches have been investigated to modify the hydrophilic nature of lignocellulosic materials, including surface modifications using silane treatments, acetylation, wax etc. Although these surface modifications can decrease the rate of water uptake by the materials, the amount of water uptake at saturation remains unchanged. In fact, the lumen diameter is so small that the rise of liquid, even with a hydrophobic surface, can still occur. Therefore, the only way to halt the water uptake driven by capillary action in lignocellulosic materials is to apply a uniform cover on the material surface in addition to filling the lumen with dense material. In the current research project, the vascular structure of softwood (Spruce) is obstructed by silica nanoparticles using the impregnation technique as one of the advanced methods to reduce the water absorption capacity in wood. This process can form a thin film of nanoparticles on solid objects with complex geometries. In addition, the technique can fill up the cavities and voids of porous materials and prevent the capillary action inside the Lumina. In this method, the wood specimen is dipped into the solution, silica 40 (wt. %) colloidal solution. Then the solvent is evaporated which results in the formation of nanoparticles in the form of thin films or particulates. The former may change the moisture absorption on the surface and the later reduces the capillarity of the vascular system. This project aims to find the optimal impregnation condition to minimize the water uptake capacity of wood in order to increase wood physical and mechanical stabilities. Three immersing times (i.e. short, medium, and long) were used to coat wooden samples with the silica colloidal solution. The samples were conditioned in wet environments with specificiii relative time and then their weight as percentage change were examined. To investigate the capability of the method to obstruct the vascular structure of the wood samples, the characteristic process was done in the next step by some common tests such as X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Water Contact Angle (WCA), etc. The results from the experiments show that dip-coating the wood samples with silica nanoparticle colloidal solution had effect on the amount of water absorption, but significant levels of reduction in water attraction was achieved with considering the other effective parameters such as duration of each set, the number of sets that are conducted, and impregnation in vacuumed condition. More research is needed to quantify the benefits of using nanoparticle in these applications.

Deeper understanding and technological progress in materials physics demand exploration of soft and hard matter at their relevant length scales. This research focuses on the nanometer length scale investigation of structural changes required for membrane fusion in virus nanoparticles and nano-spectroscopic investigation of layered material surfaces implementing scattering type scanning near-field optical microscopy (s-SNOM). Spectroscopy and imaging experiments were deployed to investigate the chemical and structural modifications of the viral protein and lipid bilayer under various environmental pH variations. It has been shown that breakage of viral membrane could occur even without the presence of a targeting membrane, if the environment pH is lowered. This is in contrary to the current viral fusion model, which requires virus binding to a host cell membrane for forming the fusion pore to release the viral genome. The fusion inhibitor compound 136 can effectively prevent the membrane breakage induced by low pH. The chemical surface stability and degradation of black phosphorus (BP) under ambient conditions have been studied using s-SNOM. We found that the degraded area and volume on the surface of black phosphorus increase with time slowly at the start of degradation and enlarge rapidly (roughly exponentially) afterward and reach saturation growth following S-shaped growth curve (sigmoid growth curve). The theoretical model presented suggests that the degraded sites in the adjacent surrounding causes the experimentally observed exponential growth of degraded area at the initial stage. By studying the BP surfaces coated by Al2O3, boron nitride (BN) and hybrid BN/Al2O3 layers through the period up to 6 months, it has been concluded that ~5 nm thin hybrid layer of BN/Al2O3 helps the surface passivation of BP flakes of thickness ~30 nm. This is supported by the electrical characterization results of BP field effect transistor coated with a BN/Al2O3 layer. We have performed infrared nano-spectroscopy on muscovite mica exfoliated on silicon and silicon dioxide substrates. We show that the near-field profile in s-SNOM can penetrate down to several hundreds of nanometers and enable spectroscopy of buried structures. We found spectral broadening of mica as its thickness increases revealing clearly the effect of size on the absorption response.

Amorphous Mg-Cu-Y metallic glasses are established by density functional theory and simulated annealing method in this study. The mechanical properties of amorphous Mg-Cu-Y metallic glasses are investigated by molecular statics simulations for the nano-indentation and the nano-scratch process. In this study, some potential energy parameters are obtained by fitting for describing the Mg-Cu-Y system. The bulk modulus, the Young¡¦s modulus and X-ray structure of the Mg-Cu-Y system are calculated. Our results are within 10% error compared with experimental values, which prove the correctness of fitted potential parameters. For the cases of nanoindentations, the indentation force-displacement and the influenced depth are calculated. The mechanical properties are obtained are close to experimental results. The both ¡§slip vector¡¨ and Honeycutt-Andemen index (HA index) parameters are also used to study the deformation behavior and bond-type of a group of atoms. Our results indicate that the influenced depths can be affected by the tip indentation and the gather of copper atoms. The gather of copper atoms can provide the resistance and strengthen the mechanical properties of Mg-Cu-Y material. On the other hand, our results indicate that the amorphous structure of Mg-Cu-Y metallic glasses cannot be transferred to crystal structure during nano-indentation process by analysis of HA index. For the cases of nano-scratch, two different scratch depth (5Å and 15Å) are investigated to understand the understand the depth effect. the scratch force-displacement curve is also obtained. As the same with nano-indentation results, the scratch force will increase because the gather of copper atoms and provide the resistance.

Since the discovery of nanomaterials in early ninety’s, a remarkable progress in the synthesis of nanocomposites has been reported looking for a new better material with improved physical and chemical properties for a variety of applications in almost all fields. The science and technology of nanocomposites has created great excitement and expectations in the last decade too. In addition to that, researches in this area have been focusing on the nanoscale second phase embedded in the polymeric matrix that gives physical and chemical properties that cannot be achieved by ordinary material synthesis methods. Researchers have also discovered that incorporating the right amount of nanoparticles into a polymer matrix pose a remarkable strength and flexibility and that industries should be able to integrate the outcome of their researches widely in high performance applications in the field of biomedical engineering, aerospace, marine, high speed parts in engines, packaging and sports gadgets. With the new methods of synthesis and tools for characterisation, nanocomposite science and technology is now experiencing explosive growth. Taking advantage of the need and the properties of the nanomaterials, through this research a new nano-enhanced composite is developed through addition of nanofiller into epoxy matrix to cater for varied applications. The physical and mechanical properties of the identified nanomaterial reinforced polymer composite were characterised by experimentation in order to ascertain the improvement in tensile, compressive and flexural properties as well as the adhesion of the matrix to the substrate. Also, while addressing potential enhancements like improved mechanical strength, better dimensional stability, higher thermal stability, better abrasion resistance, hard and wear resistance, better chemical properties like better flame retardance, anticorrosive and antioxidation, adequate importance was given to easy and bulk processability and most importantly the commercial viability as well. This nano-enhanced nanocomposite was then optimised. Based on these results, it has been established that epoxy reinforced with 1% percent of nanoclay can significantly improve the mechanical properties without compromising the weight or processability of the composite. Thus, a futuristic and much promising nano-enhanced epoxy composite has been successfully made ready for commercialisation.

Since the discovery of nanomaterials in early ninety’s, a remarkable progress in the synthesis of nanocomposites has been reported looking for a new better material with improved physical and chemical properties for a variety of applications in almost all fields. The science and technology of nanocomposites has created great excitement and expectations in the last decade too. In addition to that, researches in this area have been focusing on the nanoscale second phase embedded in the polymeric matrix that gives physical and chemical properties that cannot be achieved by ordinary material synthesis methods. Researchers have also discovered that incorporating the right amount of nanoparticles into a polymer matrix pose a remarkable strength and flexibility and that industries should be able to integrate the outcome of their researches widely in high performance applications in the field of biomedical engineering, aerospace, marine, high speed parts in engines, packaging and sports gadgets. With the new methods of synthesis and tools for characterisation, nanocomposite science and technology is now experiencing explosive growth. Taking advantage of the need and the properties of the nanomaterials, through this research a new nano-enhanced composite is developed through addition of nanofiller into epoxy matrix to cater for varied applications. The physical and mechanical properties of the identified nanomaterial reinforced polymer composite were characterised by experimentation in order to ascertain the improvement in tensile, compressive and flexural properties as well as the adhesion of the matrix to the substrate. Also, while addressing potential enhancements like improved mechanical strength, better dimensional stability, higher thermal stability, better abrasion resistance, hard and wear resistance, better chemical properties like better flame retardance, anticorrosive and antioxidation, adequate importance was given to easy and bulk processability and most importantly the commercial viability as well. This nano-enhanced nanocomposite was then optimised. Based on these results, it has been established that epoxy reinforced with 1% percent of nanoclay can significantly improve the mechanical properties without compromising the weight or processability of the composite. Thus, a futuristic and much promising nano-enhanced epoxy composite has been successfully made ready for commercialisation.

Since the discovery of nanomaterials in early ninety’s, a remarkable progress in the synthesis of nanocomposites has been reported looking for a new better material with improved physical and chemical properties for a variety of applications in almost all fields. The science and technology of nanocomposites has created great excitement and expectations in the last decade too. In addition to that, researches in this area have been focusing on the nanoscale second phase embedded in the polymeric matrix that gives physical and chemical properties that cannot be achieved by ordinary material synthesis methods. Researchers have also discovered that incorporating the right amount of nanoparticles into a polymer matrix pose a remarkable strength and flexibility and that industries should be able to integrate the outcome of their researches widely in high performance applications in the field of biomedical engineering, aerospace, marine, high speed parts in engines, packaging and sports gadgets. With the new methods of synthesis and tools for characterisation, nanocomposite science and technology is now experiencing explosive growth. Taking advantage of the need and the properties of the nanomaterials, through this research a new nano-enhanced composite is developed through addition of nanofiller into epoxy matrix to cater for varied applications. The physical and mechanical properties of the identified nanomaterial reinforced polymer composite were characterised by experimentation in order to ascertain the improvement in tensile, compressive and flexural properties as well as the adhesion of the matrix to the substrate. Also, while addressing potential enhancements like improved mechanical strength, better dimensional stability, higher thermal stability, better abrasion resistance, hard and wear resistance, better chemical properties like better flame retardance, anticorrosive and antioxidation, adequate importance was given to easy and bulk processability and most importantly the commercial viability as well. This nano-enhanced nanocomposite was then optimised. Based on these results, it has been established that epoxy reinforced with 1% percent of nanoclay can significantly improve the mechanical properties without compromising the weight or processability of the composite. Thus, a futuristic and much promising nano-enhanced epoxy composite has been successfully made ready for commercialisation.

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