Nanomaterials for Spectroscopic Applications

Kaushik Pal, Kaushik Pal

• Editore: Jenny Stanford Publishing
• Anno: 2021
• ISBN:
  9781000368277
• Edizione: 1
• Argomento: Physical Sciences
• Categoria: Industrial & Technical Chemistry

This book provides an overview of key current developments in the synthetic strategy of functional novel nanomaterials in various spectroscopic characterizations and evaluations and highlights possible future applications in nanotechnology and materials science. It illustrates the wide-ranging interest in these areas and provides a background to the later chapters, which address the novel synthesis of high-yield nanomaterials and their biomaterials, graphene, polymeric nanomaterials, green nanomaterials, green polyester, liquid crystal electro-optic switching applications, nanobiotechnology, transition metal oxides, response characteristics of exclusive spectroscopic investigation as well as electron microscopic study, flexible and transparent electrodes, optoelectronics, nanoelectronics, smart displays, switchable device modulation, health care, energy storage, solar/fuel cells, environmental and plant biology, social, ethical, and regulatory implications of various aspects of green nanotechnology, as well as significant foreseeable spectroscopic applications of key functional nanomaterials. Given appropriate regulation for and research on the topics covered, commercial production of manufactured novel composite materials can be realized. Furthermore, the many discoveries highlighted in the book can modulate spectroscopic performances with technical excellence in multidisciplinary research of high competence.

Chapter 1

An Emerging Avenue of Functional Graphene Aggregated Liquid Crystalline Hybrid Nanocomposite Diverse Attempts: Key Challenges and Novel Premises

Asiya SI^a and Kaushik Pal^b

^a Bharath Institute of Higher Education and Research (BIHER), 173 Agharam Road, Selaiyur, Chennai 600073, Tamil Nadu, India

^b University Federal Rio de Janeiro, Cidade Universitária, Rio de Janeiro - RJ, 21941-901, Brazil

[email protected]

Recently, semiconductor nanomaterials dopped liquid crystal design and as well as cultivates highly centralized on numerous approaches towards the development of innovative and assorted applications in the area of Nanoscience and Nanotechnology. Emerging nano-materials have in recent times been employed to a major extent to revise the physical properties of liquid crystals by dopping ultrathin graphene nanostructures. The self-organized liquid crystalline optical material is exploited to order templates and orient nano-materials. Moreover, nanomaterials controllable growth dynamics of nanorods, nanowires, nanospikes, nanoparticles, nanoflakes and graphene oxide (GO) homogeneously blended into lyotropic liquid crystal phases when isotropic host solvents are present. These results contribute to a variety of entirely promising applications, most of them also discussed in this exclusive chapter. Hence, the architectures of functional nanomaterials with nanometer scale dimension beneficial with the treating of material on an industrial scale. Experimental motivation behind nanofabrication is to create nano scale structures that form part of a system, device, or component in huge amounts and cost-effective, also known as top-down and bottom-up attempts. Exploration of data, however, produces an incoherent interpretation of the favorable effects of nanostructures on the physical properties of LC hosts. The brand new work must be credited to an excellent outcome of significant nanomaterials size and shape dependent extensive morphology, dispersibility and novel functionalization.

1.1 Introduction

The liquid crystal (LC) is one of the precious materials are quite different, yet share some common features, for example, their beauty, distinguished optical properties and a competition of high prices per gram. Recently, keeping in pace with topical science and modern technology, already LCs have entered into the fascinating domains of Nanoscience and Nanotechnology. This chapter explores most recent and significant innovations in ‘Liquid Crystal Nanoscience’ embracing contemporary nanomaterials different kinds of structural varieties, e.g., nanowires, nanorods, nanospikes, nanoflakes, and nanoparticles.

Indeed, LCs are soft materials that show both order and mobility on a molecular, supra molecular level and as well as macroscopic level. They are well known as active components in liquid crystal displays (LCDs), but many other commercial applications have also been explored. Liquid crystals are self-paced anisotropic fluids that are thermodynamically located phase that exist between crystalline (ordered) and the isotropic liquid phase (disordered), presenting the liquid fluidity as well as long-range lattice order seen in crystal-like solids [1–3]. The peculiar state of phase is known as ‘mesophases’. The homogeneous distribution of 0-, 1- and 2-dimensional nanomaterials/graphene into liquid crystalline materials for the improvement of properties, liquid-crystalline hybrid nanocomposite matrix phase behavior of nanomaterials themselves, self-assembly and alignment of nanomaterials in liquid-crystalline media, and the high yield controllable synthesis of nanomaterials by using liquid crystals as ‘templates’ or ‘precursors’ have been highlighted and explored in this chapter [2]. Even predicted that, the ‘fourth sate of matter’ is most likely to play more prominent positions in Nanotechnology and advanced Material Science in the years to come. Normally, the two common range of LCs are ‘thermotropic LCs’ and lyotropic LCs’ [4–7]. Based on the shape of their constituent molecules, e.g. thermotropic LCs are further differentiated into calamitic due to ‘rod-like,’ discotic for disk-like and sanidic for brick-like or lath-like, bent-core for bananalike molecules Fig. 1.1 [8].

Figure 1.1 Classification of various phases and different kinds of liquid crystal structures, i.e., discotic, calamitic and bent-core shape. A schematic illustration of different thermotropic LC phases observed on heating from crystalline state, e.g., Smectic A to Smectic C to nematic and cholesteric. Reproduced with permission from Rastogi et al. [8], copyright © 2019 Elsevier.

Controllable growth dynamics of nanomaterials is the promising technology which will soon conquer all manufacturing technologies by providing the random synthesis of functional nanomaterials capable of meeting all present and future industrial challenges. 1D nanomaterials have gained the focus of researchers owing to their exceptional properties and possible applications in mesoscopic research and in the nanodevice synthesis. Electrospinning is the most adaptable of all reported 1D nanofabrication method and is a fairly inexpensive method that result in the production of long and continuous fibers with nanoscale diameters. Materials below 100 nm are usually referred to as nanomaterials in one, two or three dimensions and they also have special properties that vary from those of bulk counterparts. It has the potential to customize individual nanostructures and to control the functional hybrid composite morphology. The mechanism is extremely robust to handle all sorts of functional nanomaterials, that include organic and inorganic polymers, in different forms, such as solutions, emulsions, mixtures, or melts, to produce complex structures, including porous, hollow, core-shell, etc.

This chapter offers an outline of the latest development in the research area of Nanoscience by designing nanomaterials that can be self-assembled in several directions into functional superstructures. Though assembly of nanostructures was caused by different methods, the usage of LC as a coordinating medium to cause nanoparticles to assemble themselves is an active tool. A variety of LC nanoparticle hybrid structures, which are the most widely utilized material in the fabrication of such hybrid matrixes, were well investigated.

1.2 Liquid Crystalline Materials by Nanodopants

Outstanding electro-optic properties of the liquid crystal has been well applicable for commercialized display. However, the novel advancement in smart technologies demanded improved visual requirements which the traditional LC dispersion failed to meet. Innovative nanomaterials were explored in the quest for liquid crystal displays with less driving volta...