Polymer/Clay Nanocomposites Produced by Dispersing Layered Silicates in Thermoplastic Melts

Results of the studies of technology, structural features and properties of polymer/clay nanocomposites (n-PCM) prepared by melt compounding of thermoplastic polymers are systematized. Special attention is given to the analysis of the effect of nanoclays modification with surfactants on properties of nanocomposites and preparation features of nanomaterials based on polar, non-polar thermoplastics and polymer blends. Effect of technological factors and special compounding regimes in the technology of n-PCM with advanced technical characteristics is considered. Results of the original studies of the structure and properties of the hybrid composites, filled by high modulus fibers in addition to nanoclays, are presented.

Influence of Zinc Oxide Nanoparticles on the Optical, Dielectric and Electromagnetic Interference Shielding Performance of Polystyrene Films

In the present work, Zinc oxide (ZnO) nanoparticles are synthesized using solvothermal technique. Polystyrene-ZnO (PS/ZnO) nanocomposite films are synthesized by solution casting procedure. PS/ZnO films are analyzed by XRD, FTIR and UV-Vis spectroscopic techniques. The addition of ZnO into the PS film is found to decrease the optical band gap (OBG) from 4.07 eV to 1.86 eV. Frequency dependence of dielectric constant (ε′), loss tangent (tanδ), ac conductivity (σac) and electromagnetic (EM) interference shielding effectiveness (SE) studies have been undertaken on the pure PS and PS/ZnO films. Insertion of ZnO into pure PS polymer matrix is found to enhance ε′, tanδ, σac, and SE considerably. The ε′ and tanδ were reduced with an enhancement in the frequency. σac of PS/ZnO nanocomposites was enhanced with rise in frequency and electrical conduction process in PS/ZnO film is in agreement with an electron-hopping model. EM interference SE is reduced with rise in the frequency. PS/ZnO films were proven as a favorable functional substance for the absorbing of EM waves at lower frequencies.

Nanomaterials and Nanocomposites Thermal and Mechanical Properties Modelling

This chapter deals with the modelling of nanomaterial and nanocomposite mechanical and thermal properties. Enrichment in the technology requires materials having higher thermal properties or higher structural properties. Nanomaterials and nanocomposites can serve this purpose accurately for aerospace or thermal applications and structural applications respectively. The thermal system requires materials having high thermal conductivity while structural system requires materials having high strength. Selection of the material for particular application is very critical and requires knowledge and experience. Al, Cu, TiO2, Al2O3, etc. are considered for thermal applications while epoxy-glass, FRP, etc. are considered for structural applications. Modelling of these nanomaterials and nanocomposites is done with the help of different mathematical models available in the literature. Results show that addition of the nanoparticle/composite in the base material can enhance the thermal and structural properties. Results also show that amount of weight percentage added also affects the properties.

Immiscible Two-Phase Parallel Microflow and Its Applications in Fabricating Micro- and Nanomaterials

The immiscible two-phase flow behaves nonlinearly, and it is a challenging task to control and stabilize the liquid-liquid interface. Parallel flow forms under a proper balance between the driving force, the friction resistance, and the interfacial tension. The liquid-solid interaction as well as the liquid-liquid interaction plays an important role in manipulating the liquid-liquid interface. With vacuum-driven flow, long and stable parallel flow is possible to be obtained in oil-water systems and can be used for fabricating micro- and nanomaterials. Ultra-small Cu nanoparticles of 4~10 nm were synthesized continuously through chemical reactions taking place on the interface. This makes it possible for in situ synthesis of conductive nanoink avoiding oxidation. Well-controlled interface reactions can also be used to produce ultra-long sub-micro Cu wires up to 10 mm at room temperature. This method provided new and simple additive fabrication methods for making integrated microfluidic devices.

Application of Magnetic Nanomaterials for Water Treatment

The availability of clean drinking water becomes a critical issue for all the people of the world due to a rapid increase in population and industrialization. The water bodies get contaminated due to the discharge of wastewater, that will not only disturb the aquatic life but also badly affect human health. Therefore, different methods are adopted to treat the contaminated water to make it clean and safe for people. In last few years, the nanomaterials have gained much attention for water treatment because of their unique properties. Among all nanomaterials, magnetic nanomaterials are considered more efficient and attractive because of their easy separation and reusable property. In this chapter, a brief review related to synthesis and characterization of MNM was studied along with their application in removal of dyes, heavy metals, and microbes from wastewater through simple adsorption processes.

Ultrasound-Assisted Synthesis of Nanostructured Oxide Materials

This chapter is focused on the use of high intensity ultrasound for the preparation of nanostructured materials with an emphasis on recent prominent examples of the production of dense or porous metal oxides through sonochemical and ultrasonic spray pyrolysis routes. Sonochemistry enables the synthesis of oxides that are often unachievable by traditional methods or affords known materials with shape, size, and nano/microstructure control under fast reaction conditions. The fundamental principles of acoustic cavitation, as well as the main ultrasonic parameters affecting the cavitation phenomenon, are first summarized. Next, the applications of ultrasound in the synthesis of nanostructured oxide materials following both preparation methods are reviewed. Particular focus is given to the ultrasound-assisted synthesis of metal oxide nanoparticles for energy applications.

Newer Approaches in Phytoremediation

The heavy metal pollution problem is all over the world. Plant-growth-promoting bacteria (PGPB) has transformed heavy metals present in the soil, which removes and minimizes their toxic effects. This chapter highlights the role of plant-growth-promoting bacteria, chelating agents, and nanoparticles for remediation of heavy metals; their mechanism of action; and their applications approach of hyperaccumulation. Therefore, this chapter focuses on the mechanisms by which microorganisms, chelating agents, and nanoparticles can mobilize or immobilize metals in soils and the nano-phytoremediation strategies are addressed for the improvement of phytoextraction as an innovative process for enhancement of heavy metals removal from soil.

Relevance of Chemically Functionalized Nano-Fillers and Modified Nanocomposite in Energy Systems

Reliable energy systems and advances in nanotechnology together will play key role in channeling future cutting edge inventions and developments in all spheres. In this review article, the pertinence of functionalizing nanofillers and modifying nanocomposites for improved performance in various energy applications such as energy conversion, energy efficiency, energy storage, alternative energy and energy saving are expounded. This article also presents structures and unique properties of commonly used nanofillers; advances, improvement potentials and characterization of nanocomposites used in energy systems. Theoretical and experimental literature reviewed revealed that nanofillers engender improved properties in polymeric matrices. Functionalization is applicable to all types of nanofillers in use today, a number of functionalized nanofillers are already commercially available; and more extensive research is needed to achieve optimal improved results with the use of nanofillers and nanocomposites in various fields of applications.

TiO2 Nanotubes Transformation Into 4nm Anatase Nanoparticles

The scope of this work shows novel experimental findings on preparing anatase TiO2 nanoparticles, first anodizing titanium into an organic media for obtaining TiO2 nanotubes, and using these as a photocatalytic active electrode in treating water polluted with organic contaminants. The substrates were grit blasted to obtain mechanical fixation of the generated nanotubular TiO2 structure. This was successfully achieved without diminishment of the nanotubes order and with a self-leveling of the outer surface. A new phenomenon has been investigated consisting of the process of oxidation of the nanotubes in water after anodizing. Along this process, methyl orange added to the aqueous solution was discolored as part of the redox reaction involved. The final state of the modified layer was composed of conglomerates of almost completely crystalline TiO2 nanoparticles, around 4 nm in size, consisting of anatase. SEM and TEM images show the transition of the amorphous nanotubes (atomic disorder/nanometric order) to crystalline disordered particles (atomic order/nanometric disorder).

Synthesis of Epoxy Nanocomposites

The formation processes of epoxy nanocomposites with carbon (nanotubes, graphene, and graphite), metal-containing, and aluminosilicate (montmorillonite and halloysite tubes) fillers are considered. A high reactivity of epoxy groups and a thermodynamic miscibility of epoxy oligomers with many substances make it possible to use diverse curing agents and to accomplish curing reactions under various technological conditions. Epoxy nanocomposites are designed to realize to the same extent the unique functional properties of nanoparticles: electric, magnetic, optical, chemical, and biological. The mutual effect of both a matrix and nanoparticles on the composite formation is discussed.