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The paper reports the use of visible 532 nm wavelength of 7 nS pulse obtained from Q-switched Nd:YAG laser at 10 Hz repetition-based time-domain photoacoustic spectroscopy for measuring the effect of carbon and inorganic fillers blending in natural rubber (NR)/chlorobutyl rubber (CIIR). All the measurements were carried out in the indigenously designed solid photoacoustic (PA) cell of $$5 \times 5 \times 6 \,\hbox {cm}^{{3}}$$ made of aluminum. A pre-polarised microphone of 50 mV/Pa responsivity coupled with a pre-amplifier was used as the sensor. The time-domain PA signal was recorded using a 200 MHz oscilloscope. The time-domain signal was converted into frequency-domain signal using indigenously designed data acquisition software developed using lab view software. The experimental data were also used to measure the absorption coefficients in the $$1.672\hbox {--}4.48 \,\hbox {cm}^{{-1}}$$ range. The absorption coefficient value varies with respect to the variation of clay percentage in the rubber matrix. We also calculated the thermal diffusivity, thermal diffusion coefficient and penetration depth as $$1.0405\hbox {--}1.0698 \times 10^{\mathrm {-5}}\,\hbox {cm}^{\mathrm {2}}~\hbox {s}^{{-1}}$$ , $$8.165\hbox {--}8.602 \,\hbox {cm}^{{-1}}$$ , $$1162\hbox {--}1224.6 \,\mu \hbox {m}$$ , respectively. Finally, we have ascertained the effect of fillers on the viscosity of natural and chlorobutyl rubber samples using Einstein–Guth–Gold equation and determined the size of the filler particles.

Scientific advancements in the field of high-power transmission and distribution of electrical energy revolutionized the field of high-performance polymer-based electrical insulation systems. Cross...

International audience; Nanomaterials have engaged response from the scientific world in recent decades due to their exceptional physical and chemical properties counter to their bulk. They have been widely used in a polymer matrix to improve mechanical, thermal, barrier, electronic and chemical properties. In rubber nanocomposites, nanofillers dispersion and the interfacial adhesion between polymer and fillers influences the composites factual properties. In the present work, a comparison of the hybrid effects of carbon black with two different nanofillers (graphene oxide and nanoclay) was studied. The 70/30 composition of chlorobutyl rubber/natural rubber elastomer blend was taken as per the blend composition optimized from our previous studies. The hybrid effects of graphene oxide and nanoclay in dispersing the nanofillers were studied mainly by analyzing nanocomposite barrier properties. The results confirm that the combined effect of carbon black with graphene oxide and nanoclay could create hybrid effects in decreasing the gas permeability. The prepared nanocomposites which partially replace the expensive chlorobutyl rubber can be used for tyer inner liner application. Additionally, the reduction in the amount of carbon black in the nanocomposite can be an added advantage of considering the environmental and economic factors.

International audience; Chitin and chitosan are the second most abundant natural biopolymers in the curst of the earth. These polysaccharide biopolymers have a long linear chain-like structure connected with β-d glucosidic linkage with the functionalizable surface groups. Because of the structural features, these biomaterials exhibit unique physical, chemical, mechanical and optical properties, which contributed to the tunable and outstanding properties such as low density, high porosity, renewability, natural biodegradability, and environmental friendliness, etc. Chitin was synthesized via mechanical, chemical, chemo-mechanical, and eco-friendly biological methods and the deacetylation of the synthesized chitin carried for the preparation of chitosan. With the chemical modification used for the preparation of chitosan, there occurs some minor change in characteristics; however, most of the properties were relatable due to major similarities in the microstructures. The inherent antibacterial, non-toxic, and biodegradable properties with the ease of processibility of both polymer has the potential to become a successful alternative to its synthetic counterparts for energy and environmental applications. However, the poor mechanical and thermal properties in comparison to the conventional alternatives have restricted its widespread applications. This review addresses various areas such as extraction techniques of chitin and synthesis of chitosan, discussion of the common characteristics of both polymers together such as crystallinity, thermal properties, mechanical properties, hydrophilicity, and surface charge. Moreover, this review paper also addresses the common functionalization techniques for both polymer and the use of both unmodified chitin and chitosan along with their derivatives in environmental and energy applications such as air pollution, heavy metal adsorption, dye adsorption, biosensors, EMI shielding, fuel cell, solar cell, lithium-ion batteries, and biofuels.

The research on cellulose fiber-reinforced nanocomposites has increased by an unprecedented magnitude over the past few years due to its wide application range and low production cost. However, the incompatibility between cellulose and most thermoplastics has raised significant challenges in composite fabrication. This paper addresses the behavior of plasma-modified polyethylene (PE) reinforced with cellulose nanofibers extracted from isora plants (i.e., isora nanofibrils (INFs)). The crystallization kinetics of PE&ndash, INF composites were explained using the Avrami model. The effect of cellulose nanofillers on tuning the physiochemical properties of the nanocomposite was also explored in this work. The increase in mechanical properties was due to the uniform dispersion of fillers in the PE. The investigation on viscoelastic properties confirmed good filler&ndash, matrix interactions, facilitating the stress transfer.

International audience; In this paper, the calorimetric response of the amorphous phase was examined in hybrid nanocomposites which were prepared thanks to a facile synthetic route, by adding reduced graphene oxide (rGO), Cloisite 30B (C30B), or multiwalled carbon nanotubes (MWCNT) to lignin-filled poly(lactic acid) (PLA). The dispersion of both lignin and nanofillers was successful, according to a field-emission scanning-electron microscopy (FESEM) analysis. Lignin alone essentially acted as a crystallization retardant for PLA, and the nanocomposites shared this feature, except when MWCNT was used as nanofiller. All systems exhibiting a curtailed crystallization also showed better thermal stability than neat PLA, as assessed from thermogravimetric measurements. As a consequence of favorable interactions between the PLA matrix, lignin, and the nanofillers, homogeneous dispersion or exfoliation was assumed in amorphous samples from the increase of the cooperative rearranging region (CRR) size, being even more remarkable when increasing the lignin content. The amorphous nanocomposites showed a signature of successful filler inclusion, since no rigid amorphous fraction (RAF) was reported at the filler/matrix interface. Finally, the nanocomposites were crystallized up to their maximum extent from the glassy state in nonisothermal conditions. Despite similar degrees of crystallinity and RAF, significant variations in the CRR size were observed among samples, revealing different levels of mobility constraining in the amorphous phase, probably linked to a filler-dimension dependence of space filling

Bacterial cellulose (BC) is a multipurpose biopolymer with superior material properties, such as purity, high degree of porosity, relative high permeability to liquid and gases, high water-uptake capacity, tensile strength, and ultrafine network. This chapter explores the extraction and applications of BC from different sources. There are two main methods to produce BNC by bacterial strains. One is the static culture, which results in the accumulation of a gelatinous membrane of BNC is formed at the gas-liquid junction with the shape of the culture vessel. Applications of BC in immobilization of enzymes and cells, applications in cosmetics include facial mask, facial scrub, personal cleansing formulations, and contact lenses. BC for controlled drug delivery, transdermal drug delivery, dental drug delivery, protein delivery, tissue engineering drug delivery, macromolecular prodrug delivery, and molecularly imprinted polymer-based enantioselective drug delivery are also discussed in this chapter.

Wettability, stainability and diffusion properties of polymer (PMMA) based nanocomposites (PMMA/ZnO) have been explored with critical significance to their physicochemical perspectives and clinical implications in the maxillofacial rehabilitation of cancer and trauma patients. Wetting and diffusion of artificial saliva through the neat polymer and nano composites have been investigated in detail. The same protocol was adopted for water diffusion studies at different temperatures. Transportation mechanism and surface wettability and stainability by commonly used beverages like tea, coffee and turmeric on these composites are studied in detail. Inferences are correlated with morphological analysis by Atomic Force Microscopy (AFM) and surface roughness parameters and density measurements. No studies have been reported till date about correlating wetting enhancement to retentive qualities and diffusion resistance to anti-stainability of the prostheses in the biomedical field. Findings of the present study is highly relevant and promising as these membranes/composites offer better retention and adaptability for the prostheses on tissue base which stimulates blood circulation in that region which prevents further bone resorption. Anti-staining potential offer more acceptance and durability for the maxillofacial prostheses especially intra orally. This nano formulation is a highly durable, cost effective esthetic substitute for the conventional polymer PMMA.

Nanostructured materials in the area of optical and electronic applications are advancing more with more device development as solar panels, optoelectronic switches, batteries and sensors. This chapter particularly focuses on the optoelectronic applications. All electronic tools have one thing in common: an integrated circuit (IC) acting as their brain. Nano-electromechanical systems have evolved early years and creating sensors eyes and actuators arms at the same scale as the accompanying nanoelectronics. Recent developments in synthesis of nanomaterials with excellent electrical and mechanical properties have extended the boundaries of NEMS applications to include more advanced devices such as the non-volatile nano-electro-mechanical memory, where information is transferred and stored through a series of electrical and mechanical actions at the nanoscale (Venkateswara Rao and Kumar Yadav in Int J Eng Sci 4:6–9, 2015 [1]).

International audience; Industrial sea food residues, mainly crab and shrimp shells, are considered to be the most promising and abundant source of chitin. In-depth understanding of the biological properties of chitin and scientific advancements in the field of nanotechnology have enabled the development of high-performance chitin nanomaterials. Nanoscale chitin is of great economic value as an efficient functional and reinforcement material for a wide range of applications ranging from water purification to tissue engineering. The use of polymers and nanochitin to produce (bio) nanocomposites offers a good opportunity to prepare bioplastic materials with enhanced functional and structural properties. Most processes for nanochitin isolation rely on the use of chemical, physical or mechanical methods. Chitin-based nanocomposites are fabricated by various methods, involving electrospinning, freeze drying, etc. This review discusses the progress and new developments in the isolation and physico-chemical characterization of chitin; it also highlights the processing of nanochitin in various composite and functional materials.

Now-a-days, the nanostructured materials increased its fabrication skill and application in important sectors like energy, environment, and medicine. However, there are some concerns related to its toxicity and life time. This chapter presents some interesting techniques and analysis to measure life time and toxicity of nanoscale materials.

Nanostructured material handling, properties and applications are widely important for promptly advancing field. This chapter focuses on important synthesis methods for production of nanostructural materials and selected properties of synthesized materials.

International audience; Green chemistry started for the search of benign methods for the development of nanoparticles from nature and their use in the field of antibacterial, antioxidant, and antitumor applications. Biowastes are eco-friendly starting materials to produce typical nanoparticles with well-defined chemical composition, size, and morphology. Cellulose, starch, chitin and chitosan are the most abundant biopolymers around the world. All are under the polysaccharides family in which cellulose is one of the important structural components of the primary cell wall of green plants. Cellulose nanoparticles can be extracted from agrowaste resources such as jute, coir, bamboo, and pineapple leaves, coir etc. Chitin is the second most abundant biopolymer after cellulose, it is a characteristic component of the cell walls of fungi, the exoskeletons of arthropods and nanoparticles of chitin can be extracted from shrimp and crab shells. Chitosan is the derivative of chitin, prepared by the removal of acetyl group from chitin. Starch nanoparticles can be extracted from tapioca and potato wastes. The preparation of these nanoparticles includes both series of chemical as well as mechanical treatments; crushing, grinding, alkali, bleaching and acid treatments. Transmission electron microscopy, scanning electron microscopy and atomic force microscopy are used to investigate the morphology of nanoscale biopolymers. Fourier transform infrared spectroscopy and X-ray diffraction are being used to study the functional group changes, crystallographic texture of nanoscale biopolymers respectively. Since large quantities of bio wastes are produced annually, further utilization of cellulose, starch and chitins as functionalized materials is very much desired. These nanoparticles can be converted into smart and functional materials by functionalization through chemical modifications due to the presence of large amount of hydroxyl group on the surface. The cellulose, starch and chitin nanoparticles are currently obtained as aqueous suspensions which are used as reinforcing additives for high performance environment-friendly bio-degradable polymer materials. These nanocomposites are being used as biomedical composites for drug/gene delivery, nano-scaffolds in tissue engineering and cosmetic orthodontics. The reinforcing effect of these nanoparticles results from the formation of a percolating network based on hydrogen bonding forces.

The role of nanotechnology towards different field of application emphases by nanomaterials size, dimensions and properties. Varying nanometer size and dimensions leads to different nanostructures with unique properties, and the features of nanoparticles was identified by their synthesis route and analyses techniques. Also the chapter briefly discussed about significances and concepts of nanoscience and technology.

The specific impact caused by nanoparticles can be assessed by life cycle assessment analysis. Performing life cycle analysis and potential risk management of nanoscale materials are increasing to perform better products and further technology developments. This chapter describes methods for research developed and applied life cycle assessment (LCA) models to evaluate ENMs and nano-enabled product.

Polymer mixing is one of the direct and practical strategies for creating new superior materials for commercial and industrial applications. The polymer blend can reinforce the setting of the properties according to the focused need. The compatibility of the immiscible polymer mixing system by incorporating a new material, helps in the development of high-performance materials. In general, graft, block or random copolymers have widespread applications as compatibilizers. Compatibilization is based on a specific chemical reaction between two functional polymer components during mixing, and is known as a reactive mixing. The introduction of reactive and functional polymers into an immiscible polymer blend with a strong interaction between the two polymer components of the mixtures can improve the adhesion between the components. Functional polymers have significant importance because of the high compatibilizing efficiency since the compatibilizer is created directly between the interfaces. In this chapter the interfacial reaction and morphology, the effect of reactive polymers on the polymer mixing process, the relationship between the flow field or process parameters, the compatibilizing efficiency of a reactive compatibilizer in different mixing techniques will be discussed. The concept of reactive compatibilizer, the characterization techniques used to monitor the compatibility of functional polymers, future perspectives and challenges in this field will also be discussed in this chapter.

Nanomaterials size range from 1 to 100 nm with unique optical, electrical, magnetic, mechanic and structural properties. There are some naturally occurring nanomaterials (viruses, protein, lotus leaf, spider-mite silk, and butterfly wings etc.) and more engineered nanomaterials (Au NPs, Ag NPs, etc.) with top-down and bottom-up approaches. The chapter detailed about properties and applications of nanomaterials.

Nanostructures may define by its dimensions as one dimension, two dimension and three dimensions based on quantum confinement effects. Nanostructures are made of nanoparticles using atom by atom or electron arrangement with the help of deposition and lithography techniques. This chapter briefly describe about nanostructured materials, approach towards nanostructured materials and various types of nanostructural materials.

Nanostructured materials are becoming of major significance, and their investigations require a comprehensive approach. Depending on the size of the smallest feature, the interaction of light with structured materials can be very different. The chapter identifies the nanostructures unique properties that make the nanostructure for varying applications and detailed about the properties.

Nanostructures vary according to their materials used as organic, inorganic or hybrid structures. The nanostructured material has at least one dimension confinement and has intermediate size between macro and microscale materials. This chapter describes about the semiconductor nanostructures, organic and hybrid nanostructures and its types, also their fabrication techniques explained in detail.

Nanostructural materials are often in a metastable state. Their detailed atomic configuration depends on nanomaterial fabrication. Therefore, the properties of nanostructures can be widely adjustable by changing their size, shape and processing conditions. The below chapter discuss briefly about physics and chemistry of nanostructured materials.

Nanostructured materials development has high impact on biological, biomedical and clinical applications. The nanostructural materials applied for biological system can be an interface with high biodegradability and minimum toxicity. That concern must to be resolve with design and synthesis of nanoscale structures. This chapter describes more on biomedical application and their design techniques.

In this paper, gas permeability studies were performed on materials based on natural rubber/acrylonitrile butadiene rubber blends and nanoclay incorporated blend systems. The properties of natural rubber (NR)/nitrile rubber (NBR)/nanoclay nanocomposites, with a particular focus on gas permeability, are presented. The measurements of the barrier properties were assessed using two different gases—O2 and CO2—by taking in account the blend composition, the filler loading and the nature of the gas molecules. The obtained data showed that the permeability of gas transport was strongly affected by: (i) the blend composition—it was observed that the increase in acrylonitrile butadiene rubber component considerably decreased the permeability; (ii) the nature of the gas—the permeation of CO2 was higher than O2; (iii) the nanoclay loading—it was found that the permeability decreased with the incorporation of nanoclay. The localization of nanoclay in the blend system also played a major role in determining the gas permeability. The permeability of the systems was correlated with blend morphology and dispersion of the nanoclay platelets in the polymer blend.

The morphology, structural and other properties of nanostructured materials are analyzed by different characterization techniques. In the below characterization studies, the shapes, sizes, and structures of nanostructured materials and their distribution are investigated. This chapter discuss briefly on analysis techniques.

Other than energy, environment, electronic and biomedical applications, the nanostructured materials used in more advanced and sensitive applications like cosmetics, food processing, communication and security purpose. This chapter describes all the applications related to above mentioned sectors.