Gamma irradiation influence on mechanical, thermal and conductivity properties of hybrid carbon nanotubes/montmorillonite nanocomposites

Modification of thermal and electrical characteristics of hybrid polymer nanocomposites through gamma irradiation for advanced applications

In this article, we present a straightforward in-situ approach for producing Ag NPs incorporated in graphene oxide (GO) blended with glutaraldehyde (GA) cross-linked polyvinyl alcohol (PVA) matrix. Samples are γ-irradiated by doses of 2, 5, and 10 kGy and in comparison with the pristine films, the thermal conductivity ('k') and effusivity are measured. 'k' decreases with irradiation doses up to 5 kGy and further increase in the dosage results increase in 'k'. We performed FDTD modeling to verify the effect of polarization and periodicity on the absorptivity and emissivity spectra that are correlated to the 'k' and effusivity, empirically. Hence, we can confess that the structural properties of the prepared hybrid nanocomposite are manipulated by γ-irradiation. This attests that the PVA/GO-Ag/GA nanocomposite is radiation-sensitive and could be employed for thermal management systems. Moreover, their strong electrical insulation, as the measured dc conductivity of the γ-irradiated samples is found to be in the range of 2.66 × 10-8-4.319 × 10-7 Sm-1, which is below the percolation threshold of 1.0 × 10-6 Sm-1, demonstrates that they are excellent candidates for the use of thermal management materials. The low 'k' values allow us to use this promising material as thermal insulating substrates in microsensors and microsystems. They are also great choices for usage as wire and cable insulation in nuclear reactors due to their superior electrical insulation.

Utilization of electron beam irradiated carboxymethyl cellulose/polyvinyl alcohol/banana peels composite film for remediation of dyes from wastewater

In this work, polymeric composite films were fabricated utilizing stable, non-toxic, soluble, low-cost, good mechanical, and biocompatible polymers such as CMC and PVA with the waste of one of the most current fruits consumed worldwide banana peel waste (BP) as a filler. Sequences of carboxymethyl cellulose/polyvinyl alcohol/banana peel (CMC/PVA/BP) composite films with various amounts of BP utilizing eco-friendly technique (electron beam) (EB) irradiation were prepared to eliminate common hazardous organic pollutants such as methylene blue (MB) dye from its solutions. Physical characteristics like; swelling and gel % were examined. The chemical structure, thermal stability, and surface morphology were examined utilizing FT-IR, TGA, DSC, XRD, EDX, and SEM. Additionally, the UV/Vis spectroscopy study was investigated to study the impact of the various parameters such as irradiation, contact time, pH, temperature, adsorbent dosage, and initial concentration on removal efficiency % of MB dye onto the prepared composite films. The adsorption process fitted with the Langmuir model, pseudo-second-order kinetic model, endothermic, favorable, and spontaneous. The adsorption capacity of MB dye onto the CMC/PVA/BP composite film was 19.6 mg/g at the optimum conditions: irradiation dose = 20 kGy, contact time = 120 min, pH = 10, temperature = 25 °C, adsorbent dosage = 0.1 g and initial conc. = 10 mg/L.

Irradiation Effects in Polymer Composites for Their Conversion into Hybrids

In this paper several aspects of profound modifications caused by high energy exposures are presented as possible candidates for the efficient adjusting processing of polymer materials. The class of hybrid composites receives special attention due to the large spectrum of formulations, where the interphase interaction decisively influences the material properties. They represent potential start points for the intimate uniformity of hybrid morphologies. Their radiation processing turns composites onto hybrid morphology with expected features, because the transferred energy is spent for the modification of components and for their compatibility. The essential changes achieved in radiation processed composites explain the new material behavior and durability based on the peculiar restructuring of polymer molecules that occurred in the polymer phase. During high energy irradiation, the interaction between intermediates born in the constitutive phases may convert the primary composites into hybrids, integrating them into large applicability spheres. During the radiation exposure, the resulting hybrids gain a continuous dispersion by means of new chemical bonds. This type of compounds achieves some specific structural modifications in the polymer phase, becoming stable hybrid composites. The functional properties of hybrids definitely influence the material behavior due to the molecular changes based on the structural reasons. The radiolysis of the vulnerable component becomes an appropriate opportunity for the creation of new material with improved stability. The radiation treatment is a proper conversion procedure by which common mixtures may become continuously reorganized. This review presents several examples for the radiation modifications induced by radiation exposure that allow the compatibilization and binding of components as well as the creation of new structures with improved properties. This approach provides the reference patterns for the extension of radiation processing over the well-conducted adjustments of polymer composites, when certain material features are compulsorily required. From this review, several solutions for the adjustment of regular polymer composites into hybrid systems may become conceivable by the extended radiation processing.

Gamma Radiation Processed Polymeric Materials for High Performance Applications: A Review

The polymeric properties are tailored and enhanced by high energy radiation processing, which is an effective technique to tune the physical, chemical, thermal, surface, and structural properties of the various thermoplastic and elastomeric polymeric components. The gamma and electron beam radiation are the most frequent radiation techniques used for crosslinking, compatibilizing, and grafting of various polymer blends and composites systems. The gamma radiation-induced grafting and crosslinking are the effective, rapid, clean, user-friendly, and well-controlled techniques for the polymeric materials for their properties improvement for high performance applications such as nuclear, automobile, electrical insulation, ink curing, surface modification, food packaging, medical, sterilization, and health-care in a different environment. Similarly, electron beam radiations crosslinking has been a well-known technique for properties development and has economic benefits over chemical crosslinking techniques. This review focuses on the development of polymeric multi component systems (functionalized polymer, blends, and nanohybrids), where partially nanoscale clay incorporation can achieve the desired properties, and partially by controlled high energy radiations crosslinking of blends and nanocomposites. In this review, various investigations have been studied on the development and modifications of polymeric systems, and controlled dose gamma radiation processed the polymer blends and clay-induced composites. Radiation induced grafting of the various monomers on the polymer backbone has been focused. Similarly, comparative studies of gamma and electron beam radiation and their effect on property devlopment have been focused. The high energy radiation modified polymers have been used in several high performance sectors, including automotive, wire and cable insulation, heat shrinkable tube, sterilization, biomedical, nuclear and space applications.

A Brief Review on the High-Energy Electromagnetic Radiation-Shielding Materials Based on Polymer Nanocomposites

This paper revises the use of polymer nanocomposites to attenuate high-energy electromagnetic radiation (HE-EMR), such as gamma radiation. As known, high-energy radiation produces drastic damage not only in facilities or electronic devices but also to life and the environment. Among the different approaches to attenuate the HE-EMR, we consider the use of compounds with a high atomic number (Z), such as lead, but as known, lead is toxic. Therefore, different works have considered low-toxicity post-transitional metal-based compounds, such as bismuth. Additionally, nanosized particles have shown higher performance to attenuate HE-EMR than those that are micro-sized. On the other hand, materials with π-conjugated systems can also play a role in spreading the energy of electrons ejected as a consequence of the interaction of HE-EMR with matter, preventing the ionization and bond scission of polymers. The different effects produced by the interactions of the matter with HE-EMR are revised. The increase of the shielding properties of lightweight, flexible, and versatile materials such as polymer-based materials can be a contribution for developing technologies to obtain more efficient materials for preventing the damage produced for the HE-EMR in different industries where it is found.