Applications of nanomaterials

This section covers environmental applications of nanomaterials insofar as they are directly applied to the pollutant of interest. The photocatalytic degradation of organic pollutants and remediation of polluted soils and water are discussed here. The high surface areas and photocatalytic activities of semiconductor nanomaterials have attracted many researchers. Semiconductor nanomaterials are commercially available, stable, and relatively nontoxic and cheap. Prominent examples that are discussed are metal oxides such as Ti02 and ZnO and a variety of Fe-based nanomaterials. 

Studies on the use of hydrothermal, microwave-assisted, and reflux synthesis methods for the development and application of nanomaterials have been reviewed. An important aspect of the green synthesis of metallic nanopartides involves techniques that make use of biological materials such as plant extracts and microorganisms. The design of nanomaterials and control of their desired properties have been reviewed. The unique properties of manufactured nanomaterials offer many potential benefits. 

Problems with the use of electrochemical methods arise from attempts to create reliable, convenient and user-friendly non-toxic sensors. New technologies and materials enable the development of new sensors with unique properties, which has become possible, in particular, due to application of nanomaterials as (i) transducers, (ii) catalytic constituent of enzyme-free sensors and (iii) labels for immunosensors. 

A common theme throughout this volume involves the adsorption and interfacial, especially biointerfacial, behaviour of all of the above mentioned nanomaterials. For environmental and human protection, the adsorption of heavy metal ions, toxins, pollutants, drugs, chemical warfare agents, narcotics, etc. is often desirable. A healthy mix of experimental and theoretical approaches to address these problems is described in various contributions. In other cases the application of materials, particularly for biomedical applications, requires a surface rendered inactive to adsorption for long term biocompatibility. Adsorption, surface chemistry, and particle size also plays an important role in the toxicological behaviour of nanoparticles, a cause for concern in the application of nanomaterials. Each one of these issues is addressed in one or more contributions in this volume. 

Braue, E.H., Hobson, S.T. (2005). Nanomaterials as active components in chemical warfare agent barrier creams. In Defense Applications of Nanomaterials, Vol. 11 (A.W. Miziolek et al., eds), pp. 153-69. Oxford University Press, New York, NY. 

From the view point of nanoscience, many research efforts have been put forward to achieve simplicity in the steps leading from the material s synthesis to final applications of nanomaterials. Due to the small size inherent to nanomaterials, manipulation and assembly processes following their synthesis are much more complicated and time consuming than their bulk counterparts. Therefore, numerous studies focused on novel synthetic methods which allow spatial and orientational control of nanomaterials during their growth process. These efforts will be discussed more in Section 12.4. These approaches enable the use of nanomaterials directly upon their synthesis, without going through complex and costly fabrication steps to assemble nanomaterials into application-ready devices and platforms. 

Particularly promising near-term applications of nanomaterials that may yield order-of-magnitude improvements over current generation technologies include (1) membrane separations, (2) catalysis, (3) contaminant sensing, (4) energy production and storage, and (5) contaminant immobilization. 

The ramifications of nanotechnology in the food arena have yet to be fully realized. This requires further research into biopolymer assembly behavior and applications of nanomaterials in the food industry. Researchers should keep abreast of the development of research tools and what is being done to push resolution limits for techniques such as atomic force spectroscopy or the synchrotron coupled to various spectroscopic techniques and higher resolution microscopy. New techniques should be exploited and the knowledge gained used to understand the dynamics and interactions of food materials at the single-molecule level and to describe assembly behavior in quantitative thermodynamic terms. There are questions about the interactions of nanoparticles with the food matrix and within the human body. These questions need to be addressed by future research (Simon and Joner, 2008 Sletmoen et ah, 2008). 

Due to their unique optical, electronic, acoustic, magnetic, thermal characteristics and advantages as catalysts, etc., the applications of nanomaterials can be found in many fields and some are listed as below [3-6] ... 

University Institute of Pharmaceutical Sciences, UGC Centre of Advanced Studies, Punjab University, Chandigarh, India UGC Centre of Excellence in Applications of Nanomaterials, Nanoparticles Nanocomposites (Biomedical Sciences), Punjab University, Chandigarh, India... 

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