Fabrication and Model Characterization of the Electrical Conductivity of PVA/PPy/rGO Nanocomposite.

Owing to the numerous advantages of graphene-based polymer nanocomposite, this study is focused on the fabrication of the hybrid of polyvinyl alcohol (PVA), polypyrrole (PPy), and reduced graphene-oxide. The study primarily carried out the experimentation and the mathematical analysis of the electrical conductivity of PVA/PPy/rGO nanocomposite. The preparation method involves solvent/drying blending method. Scanning electron microscopy was used to observe the morphology of the nanocomposite. The electrical conductivity of the fabricated PVA/PPy/rGO nanocomposite was investigated by varying the content of PPy/rGO on PVA. From the result obtained, it was observed that at about 0.4 (wt%) of the filler content, the nanocomposite experienced continuous conduction. In addition, Ondracek, Dalmas s-shape, dose-response, and Gaussian fitting models were engaged for the analysis of the electrical transport property of the nanocomposite. The models were validated by comparing their predictions with the experimental measurements. The results obtained showed consistency with the experimental data. Moreover, this study confirmed that the electrical conductivity of polymer-composite largely depends on the weight fraction of fillers. By considering the flexibility, simplicity, and versatility of the studied models, this study suggests their deployment for the optimal characterization/simulation tools for the prediction of the electrical conductivity of polymer-composites.

Recent advances in green synthesized nanoparticles for bactericidal and wound healing applications.

Nanotechnology has become an exciting area of research in diverse fields, such as: healthcare, food, agriculture, cosmetics, paints, lubricants, fuel additives and other fields. This review is a novel effort to update the practioneers about the most current developments in the widespread use of green synthesized nanoparticles in medicine. Biosynthesis is widely preferred among different modes of nanoparticle synthesis since they do not require toxic chemical usage and they are environment-friendly. In the green bioprocess, plant, algal, fungal and cyanobacterial extract solutions have been utilized as nucleation/capping agents to develop effective nanomaterials for advanced medical applications. Several metal salts, such as silver, zinc, titanium and other inorganic salts, were utilized to fabricate innovative nanoparticles for healthcare applications. Irrespective of the type of wound, infection in the wound area is a widespread problem. Micro-organisms, the prime reason for wound complications, are gradually gaining resistance against the commonly used antimicrobial drugs. This necessitates the need to generate nanoparticles with efficient antimicrobial potential to keep the pathogenic microbes under control. These nanoparticles can be topically applied as an ointment and also be used by incorporating them into hydrogels, sponges or electrospun nanofibers. The main aim of this review is to highlight the recent advances in the Ag, ZnO and TiO2 nanoparticles with possible wound healing applications, coupled with the bactericidal ability of a green synthesis process.

Hybrid nanomaterial composed of chitosan, curcumin, ZnO and TiO2 for antibacterial therapies.

Metal nanoparticles have been tremendously utilised, such as; antibacterial and anticancer agents. Although metal nanoparticles exhibits antibacterial and anticancer activity, but the drawback of toxicity on normal cells limits their clinical applications. Therefore, improving the bioactivity of hybrid nanomaterial (HNM) and minimizing toxicity is of paramount importance for biomedical applications. Herein, a facile and simple double precipitation method was used to develop biocompatible and multifunctional HNM from antimicrobial chitosan, curcumin, ZnO and TiO2. In HNM, biomolecules chitosan and curcumin were used to control the toxicity of ZnO and TiO2 and improve their biocidal properties. The cytotxicological properties of the HNM was studied against human breast cancer (MDA-MB-231) and fibroblast (L929) cell lines. The antimicrobial activity of the HNM was examined against Escherichia coli and Staphylococcus aureus bacteria, via the well-diffusion method. In addition, the antioxidant property was evaluated by the radical scavenging method. These findings actively, support the ZTCC HNM potential, as an innovative biocidal agent for applications in the clinical and healthcare sectors.

The significance of biomacromolecule alginate for the 3D printing of hydrogels for biomedical applications.

Natural biopolymers have been widely employed as biomaterial ink hydrogels for three-dimensional (3D) extrusion bioprinting in the preparation of the next generation of bioengineering materials for healthcare applications. Alginate is a linear anionic polysaccharide with favourable properties, such as: typical rheological (gelling, viscosifying, and stabilizing dispersions) characteristics, biodegradability and biocompatibility properties. However, in order to improve alginate applicability for practical biomaterial/bio ink for advanced medical applications, it is often modified and functionalized with several polymers and nanomaterials in order to obtain better printability of alginate-based biomaterial/bio ink hydrogels. This review, principally, emphasizes the recent developments and with a comprehensive overview of alginate-based biomaterial/bio ink hydrogels and their biomaterials (3D scaffolds, tissue-like structures with hierarchical vasculatures, mimics of biological, physiological and pathological functionalities) for biomedical applications. It also addresses the significance of alginates, oxidized alginate and their functionalizations (interface) with various materials in order to improve the biomaterial/bio ink properties for 3D extrusion bioprinting applications. Finally, it provides current advances, vital roles and new perspectives of alginate-based materials and their future developments for 3D bioprinting purposes.

Density Functional Theory Interaction Study of a Polyethylene Glycol-Based Nanocomposite with Cephalexin Drug for the Elimination of Wound Infection.

In this paper, density functional theory (DFT) simulations are used to evaluate the possible use of a graphene oxide-based poly(ethylene glycol) (GO/PEG) nanocomposite as a drug delivery substrate for cephalexin (CEX), an antibiotic drug employed to treat wound infection. First, the stable configuration of the PEGylated system was generated with a binding energy of -25.67 kcal/mol at 1.62 Å through Monte Carlo simulation and DFT calculation for a favorable adsorption site. The most stable configuration shows that PEG interacts with GO through hydrogen bonding of the oxygen atom on the hydroxyl group of PEG with the hydrogen atom of the carboxylic group on GO. Similarly, for the interaction of the CEX drug with the GO/PEG nanocomposite excipient system, the adsorption energies are computed after determining the optimal and thermodynamically favorable configuration. The nitrogen atom from the amine group of the drug binds with a hydrogen atom from the carboxylic group of the GO/PEG nanocomposite at 1.75 Å, with an adsorption energy of -36.17 kcal/mol, in the most stable drug-excipient system. Drug release for tissue regeneration at the predicted target cell is more rapid in moist conditions than in the gas phase. The solubility of the suggested drug in the aqueous media around the open wound is shown by the magnitude of the predicted solvation energy. The findings from this study theoretically validate the potential use of a GO/PEG nanocomposite for wound treatment application as a drug carrier for sustained release of the CEX drug.

Numerical Investigation and Response Surface Optimization of the Effective Modulus and Electrical and Thermal Conductivities of the Borophene Nanoplatelet-Reinforced PEDOT:PSS Nanocomposite for Energy Storage Application.

Conductive organic nanocomposites have been widely employed to achieve a variety of purposes, particularly for energy storage applications, making it necessary to investigate transport properties such as electron and heat transport qualities based on geometric shapes and component materials. Due to the solid B-B bonds, unique atomic structure, and energy storage potential, borophene has received significant attention due to its reported ultrahigh mechanical modulus and metallic conduction. Herein, we investigated the effect and interaction of content materials (volume fraction) and geometric parameters such as the aspect ratio and orientation of borophene nanoplatelet (BNP) inclusions on the mechanical integrity and transport features (electrical and thermal conductivities) of a poly(3,4-ethylene dioxythiophene):poly(4-styrene sulfonate) (PEDOT:PSS) electrode. The boundary condition is crucial in developing the predictive models for the optimized mechanical and transport properties of the composites. The effective modulus, electrical conductivity, and thermal conductivity of the BNP-reinforced PEDOT:PSS-based nanocomposite are evaluated using the periodic boundary condition, the representative volume element-based finite element homogenization, and statistical analysis response surface techniques. The optimal parameters for the PEDOT:PSS/BNP nanocomposite for energy storage application are predicted based on the desirability function to have a 13.96% volume fraction of BNPs, having an aspect ratio of 0.04 at 45° inclination. The desirability value achieved for the material hinges was 0.78 with a predicted Young's modulus of 6.73 GPa, the electrical conductivity was 633.85 S/cm, and the thermal conductivity was 1.96 W/m K at a generally high predictive performance of <0.03 error. The effective thermal conductivity of the nanocomposite was determined by considering Kapitsa nanoeffects, which exhibit an interfacial thermal resistance of 2.42 × 10-9 m2 K/W. Based on these improved findings, the enhanced PEDOT:PSS/BNP nanocomposite electrode would be a promising material for metal-ion batteries.

Strength Characteristics of Electrospun Coconut Fibre Reinforced Polylactic Acid: Experimental and Representative Volume Element (RVE) Prediction.

Environmental conservation and waste control have informed and encouraged the use of biodegradable polymeric materials over synthetic non-biodegradable materials. It has been recognized that nano-sized biodegradable materials possess relatively good properties as compared to conventional micron-sized materials. However, the strength characteristics of these materials are inferior to fossil-based non-biodegradable materials. In this study, biodegradable polylactide (PLA), reinforced with treated coconut husk particulates (CCP) for improved mechanical properties, was fabricated using an electrospinning process and representative volume element (RVE) technique, and some of the obtained mechanical properties were compared. It was observed that the electrospun CCP-PLA nanofibre composites show improved mechanical properties, and some of these mechanical properties using both techniques compared favourably well. The electrospun fibres demonstrate superior properties, mostly at 4 wt.% reinforcement. Thus, achieving good mechanical properties utilising agro waste as reinforcement in PLA to manufacture nanocomposite materials by electrospinning method is feasible and provides insight into the development of biodegradable nanocomposite materials.

Applications of MXene-Containing Polypyrrole Nanocomposites in Electrochemical Energy Storage and Conversion.

The atomically thick two-dimensional (2D) materials are at the forefront of revolutionary technologies for energy storage devices. Due to their fascinating physical and chemical features, these materials have gotten a lot of attention. They are particularly appealing for a wide range of applications, including electrochemical storage systems, due to their simplicity of property tuning. The MXene is a type of 2D material that is widely recognized for its exceptional electrochemical characteristics. The use of these materials in conjunction with conducting polymers, notably polypyrrole (PPy), has opened new possibilities for lightweight, flexible, and portable electrodes. Therefore, herein we report a comprehensive review of recent achievements in the production of MXene/PPy nanocomposites. The structural-property relationship of this class of nanocomposites was taken into consideration with an elaborate discussion of the various characterizations employed. As a result, this research gives a narrative explanation of how PPy interacts with distinct MXenes to produce desirable high-performance nanocomposites. The effects of MXene incorporation on the thermal, electrical, and electrochemical characteristics of the resultant nanocomposites were discussed. Finally, it is critically reviewed and presented as an advanced composite material in electrochemical storage devices, energy conversion, electrochemical sensors, and electromagnetic interference shielding.

Crosslinking Trends in Multicomponent Hydrogels for Biomedical Applications.

Multicomponent-based hydrogels are well established candidates for biomedical applications. However, certain aspects of multicomponent systems, e.g., crosslinking, structural binding, network formation, proteins/drug incorporation, etc., are challenging aspects to modern biomedical research. The types of crosslinking and network formation are crucial for the effective combination of multiple component systems. The creation of a complex system in the overall structure and the crosslinking efficiency of different polymeric chains in an organized fashion are crucially important, especially when the materials are for biomedical applications. Therefore, the engineering of hydrogel has to be, succinctly understood, carefully formulated, and expertly designed. The different crosslinking methods in use, hydrogen bonding, electrostatic interaction, coordination bonding, and self-assembly. The formations of double, triple, and multiple networks, are well established. A systematic study of the crosslinking mechanisms in multicomponent systems, in terms of the crosslinking types, network formation, intramolecular bonds between different structural units, and their potentials for biomedical applications, is lacking and therefore, these aspects require investigations. To this end, the present review, focuses on the recent advances in areas of the physical, chemical, and enzymatic crosslinking methods that are often, employed for the designing of multicomponent hydrogels.

Morphological, Thermal, and Mechanical Properties of Electrospun Recycled Poly(ethylene terephthalate)/Graphene Oxide Composite Nanofiber Membranes.

This study investigates the influence of graphene oxide (GO) on the properties of electrospun recycled poly(ethylene terephthalate) (rPET) composite nanofiber membranes. GO nanosheet layers, with good hydrophilic properties, were incorporated at various loadings (0-8 wt %) during electrospinning. The surface morphological analysis revealed that GO loadings of less than 0.5 wt % lead to smoother fiber surfaces due to less agglomeration, as shown by the scanning electron microscope images. The smooth fiber surface shows that the nanosheets are intact within the rPET polymer matrix at low GO loadings. The differential scanning calorimetry results reveal that nucleation increases linearly with GO content as observed by the change in crystallization peak temperature (T c) of rPET from 184 to 200 °C. Both the T c and characteristic rPET crystallization peak in the X-ray diffraction pattern indicate the presence of a physical interaction between the GO sheets and the rPET polymer matrix. A decrease of up to 10° in the water contact angle at 0.5 wt % GO loading; beyond this, it starts to increase due to the agglomeration of GO sheets. From this study, it is preferable to maintain the GO content to a maximum of 0.5 wt % to maximize hydrophilicity. This has the implication of enhanced filtration permeation flux in applications where hydrophilic membranes are desired.

Computational Study of Graphene-Polypyrrole Composite Electrical Conductivity.

In this study, the electrical properties of graphene-polypyrrole (graphene-PPy) nanocomposites were thoroughly investigated. A numerical model, based on the Simmons and McCullough equations, in conjunction with the Monte Carlo simulation approach, was developed and used to analyze the effects of the thickness of the PPy, aspect ratio diameter of graphene nanorods, and graphene intrinsic conductivity on the transport of electrons in graphene-PPy-graphene regions. The tunneling resistance is a critical factor determining the transport of electrons in composite devices. The junction capacitance of the composite was predicted. A composite with a large insulation thickness led to a poor electrochemical electrode. The dependence of the electrical conductivity of the composite on the volume fraction of the filler was studied. The results of the developed model are consistent with the percolation theory and measurement results reported in literature. The formulations presented in this study can be used for optimization, prediction, and design of polymer composite electrical properties.

Investigation and Modeling of the Electrical Conductivity of Graphene Nanoplatelets-Loaded Doped-Polypyrrole.

In this study, a hybrid of graphene nanoplatelets with a polypyrrole having 20 wt.% loading of carbon-black (HGPPy.CB20%), has been fabricated. The thermal stability, structural changes, morphology, and the electrical conductivity of the hybrids were investigated using thermogravimetric analyzer, differential scanning calorimeter, X-ray diffraction analyzer, scanning electron microscope, and laboratory electrical conductivity device. The morphology of the hybrid shows well dispersion of graphene nanoplatelets on the surface of the PPy.CB20% and the transformation of the gravel-like PPy.CB20% shape to compact spherical shape. Moreover, the hybrid's electrical conductivity measurements showed percolation threshold at 0.15 wt.% of the graphene nanoplatelets content and the curve is non-linear. The electrical conductivity data were analyzed by comparing different existing models (Weber, Clingerman and Taherian). The results show that Taherian and Clingerman models, which consider the aspect ratio, roundness, wettability, filler electrical conductivity, surface interaction, and volume fractions, closely described the experimental data. From these results, it is evident that Taherian and Clingerman models can be modified for better prediction of the hybrids electrical conductivity measurements. In addition, this study shows that graphene nanoplatelets are essential and have a significant influence on the modification of PPy.CB20% for energy storage applications.

Biocidal (bacterial and cancer cells) activities of chitosan/CuO nanomaterial, synthesized via a green process.

Biopolymer-based nanomaterials have been developed as antimicrobial and anticancer agents due to their advanced physical, chemical and biomedical characteristics. Herein, chitosan-copper oxide nanomaterial was, successfully synthesized by a green method. In this process, copper salt was nucleated with Psidium guajava leaves extract in order to form the nanomaterial in the chitosan network. Attenuated total reflection-fourier transform, infrared spectroscopy, X-ray diffraction, Dynamic light scattering, Transmission electron microscope, Field emission scanning electron microscopy/Energy dispersive X-ray analysis, X-ray photoelectron spectroscopy and Photoluminescence spectroscopy techniques were, employed to characterize the synthesized nanomaterial. The average size of the nanomaterial was identified to be ∼52.49 nm with XRD. The antibacterial study of CCuO NM showed higher activity than the commercial amoxicillin against gram-positive (G + ve) (Staphylococcus aureus, Bacillus subtilis) and gram-negative (G-ve) bacteria (Klebsiella pneumonia, Escherichia coli). CCuO NM showed in-vitro anticancer potential against human cervical cancer cells (Hela) with an IC50 concentration of 34.69 µg/mL. Photoluminescence spectrum of CCuO NM showed a green emission (oxygen vacancies) observed at ∼516 nm, which is attributed to the generation of reactive oxygen species (ROS) by the nanomaterial, which is believed, to be responsible for the biocidal (cell death) effects. These results suggested that CCuO is a promising nanomaterial that could be suitable for advanced applications in the healthcare industries.

Biocidal activity of Ba2+-doped CeO2 NPs against Streptococcus mutans and Staphylococcus aureus bacterial strains.

Mishandling of antibiotics often leads to the development of multiple drug resistance (MDR) among microbes, resulting in the failure of infection treatments and putting human health at great risk. As a response, unique nanomaterials with superior bioactivity must be developed to combat bacterial infections. Herein, CeO2-based nanomaterials (NMs) were synthesized by employing cerium(iii) nitrate and selective alkaline ions. Moreover, the influence of alkaline ions on CeO2 was investigated, and their characteristics, viz.: biochemical, structural, and optical properties, were altered. The size of nano Ba-doped CeO2 (BCO) was ∼2.3 nm, relatively smaller than other NMs and the antibacterial potential of CeO2, Mg-doped CeO2 (MCO), Ca-doped CeO2 (CCO), Sr-doped CeO2 (SCO), and Ba-doped CeO2 (BCO) NMs against Streptococcus mutans (S. mutans) and Staphylococcus aureus (S. aureus) strains was assessed. BCO outperformed all NMs in terms of antibacterial efficacy. In addition, achieving the enhanced bioactivity of BCO due to reduced particle size facilitated the easy penetration into the bacterial membrane and the presence of a sizeable interfacial surface. In this study, the minimum quantity of BCO required to achieve the complete inhibition of bacteria was determined to be 1000 µg mL-1 and 1500 µg mL-1 for S. mutans and S. aureus, respectively. The cytotoxicity test with L929 fibroblast cells demonstrated that BCO was less toxic to healthy cells. Furthermore, BCO did not show any toxicity and cell morphological changes in the L929 fibroblast cells, which is similar to the control cell morphology. Overall, the results suggest that nano BCO can be used in biomedical applications, which can potentially help improve human health conditions.

Biocidal chitosan-magnesium oxide nanoparticles via a green precipitation process.

In the present scenario, the development of eco-friendly multifunctional biocidal substances with low cost and high efficiency, has become the center of focus. This study is, focused on the synthesis of magnesium oxide (MgO) and chitosan-modified magnesium oxide (CMgO) nanoparticles (NPs), via a green precipitation process. In this process, leaves extract of Plumbago zeylanica L was, used as a nucleating agent. The MgO and CMgO NPs exhibit face-centered cubic structures, as confirmed by XRD studies. Morphologically, the FESEM and TEM images showed that the MgO and CMgO NPs were spherical, with an average particle size of ~40±2 and ~37±2 nm, respectively. EDX spectra were used to identify the elemental compositions of the nanoparticles. By using FTIR spectra, the Mg-O stretching frequency of MgO and CMgO NPs were observed at 431 and 435 cm-1, respectively. The photoluminescence (PL) spectra of MgO and CMgO NPs, revealed oxygen vacancies at 499 nm and 519 nm, respectively, due to the active radicals generated, which were responsible for their biocidal activities. The toxicity effects of the nanoparticles developed, on cell viability (antibacterial and anticancer), were measured on the MCF-7 cell line and six different types of gram-negative bacteria. The antibacterial activities of the nanoparticles on: Klebsiella pneumoniae, Escherichia coli, Shigella dysenteriae, Pseudomonas aeruginosa, Proteus vulgaris and Vibrio cholerae bacteria, were studied with the well diffusion method. The MgO and CMgO NPs were tested on breast cancer cell line (MCF-7) via an MTT assay and it proved that CMgO NPs possess higher anticancer properties than MgO NPs. Overall, CMgO NPs showed a higher amount of cytotoxicity for both the bacterial and cancer cells when compared to the MgO NPs. Toxicity studies of fibroblast L929 cells revealed that the CMgO NPs were less harmful to the healthy cells when compared to the MgO NPs. These results suggest that biopolymer chitosan-modified MgO NPs can be used for healthcare industrial applications in order to improve human health conditions.

A Review on Polymer Nanocomposites and Their Effective Applications in Membranes and Adsorbents for Water Treatment and Gas Separation.

Globally, environmental challenges have been recognised as a matter of concern. Among these challenges are the reduced availability and quality of drinking water, and greenhouse gases that give rise to change in climate by entrapping heat, which result in respirational illness from smog and air pollution. Globally, the rate of demand for the use of freshwater has outgrown the rate of population increase; as the rapid growth in town and cities place a huge pressure on neighbouring water resources. Besides, the rapid growth in anthropogenic activities, such as the generation of energy and its conveyance, release carbon dioxide and other greenhouse gases, warming the planet. Polymer nanocomposite has played a significant role in finding solutions to current environmental problems. It has found interest due to its high potential for the reduction of gas emission, and elimination of pollutants, heavy metals, dyes, and oil in wastewater. The revolution of integrating developed novel nanomaterials such as nanoparticles, carbon nanotubes, nanofibers and activated carbon, in polymers, have instigated revitalizing and favourable inventive nanotechnologies for the treatment of wastewater and gas separation. This review discusses the effective employment of polymer nanocomposites for environmental utilizations. Polymer nanocomposite membranes for wastewater treatment and gas separation were reviewed together with their mechanisms. The use of polymer nanocomposites as an adsorbent for toxic metals ions removal and an adsorbent for dye removal were also discussed, together with the mechanism of the adsorption process. Patents in the utilization of innovative polymeric nanocomposite membranes for environmental utilizations were discussed.

Carboxymethyl cellulose-based materials for infection control and wound healing: A review.

The development of ideal wound dressing materials with excellent characteristics is currently a major demand in wound therapy. In recent years, carboxymethyl cellulose (CMC)-based wound dressing materials have been of immense attraction due to their noble properties, such as: biocompatibility, biodegradability, tissue resembling, low cost and non-toxic. It is used extensively, in a variety of applications in the biomedical and pharmaceutical fields. The hydrophilic nature of CMC, makes it possible to blend and cross-link with other materials, such as: synthetic polymers, natural polymers and inorganic materials and it enables the preparation of innovative wound dressing biomaterials. Hence, this review, focuses on the intrinsic characteristics of CMC-based wound dressing materials, including hydrogels, films, 3D printing, fibres, gauzes and their recent advancements in chronic wound healing.

Plastics in municipal drinking water and wastewater treatment plant effluents: challenges and opportunities for South Africa-a review.

Pervasive plastic wastes, pollution and detrimental environmental ethics are a serious threat in South Africa. Compared with global trends, most studies undertaken on plastic pollutions in water bodies across South Africa have generally been limited to marine and coastal waters. A literature review, for the last 40 years, demonstrated the scanty studies on the economic, social, health and cost implications of plastic entrainment into fresh water (sources of drinking water) and wastewater systems in South Africa. Hence, demonstrating a knowledge gap on this imperative issue, the inadequate and limited frameworks needed in assessing, evaluating and re-evaluating the menace of plastic pollution and entrainments into consumable water and wastewater treatment plants. This has hampered the local capacity, manpower, knowledge and understanding direly needed for mitigating these challenges. This work is necessitated because of the dire need in bridging the knowledge gap locally by adaptively reviewing possible challenges and opportunities for South Africa in meeting up the mandate of addressing this global threat. The emerging agreement amongst global policy-makers, educators and scientists is that environmental challenges, such as this, require, now more than ever, renewed ways of effective knowledge production and decision-making in tackling, holistically the menace of mismanaged plastic wastes and pollutions. These include but not limited to plastic education curriculum, synergised policies in fostering a circular plastic economy, overriding political will, innovative waste management systems, inclusive independent monitoring of plastic wastes, robust laws and effective enforcement strategies that are needed to promote better environmental ethics, mitigation and a sustainable environment.

Biomolecule chitosan, curcumin and ZnO-based antibacterial nanomaterial, via a one-pot process.

As a result of the existence of drug-resistant bacteria and the attendant deficiency of innovative antibiotics, the therapeutic and the clinical sectors are, continually, in search of appropriate multifunctional nanomedicines. Herein, curcumin-chitosan-zinc oxide (CCZ) was successfully synthesized by a one-pot method. Transmission electron micrograph reveals that curcumin and chitosan were layered on a hexagonal ZnO and the particles are sized to ∼48 ±2nm. X-ray diffractogram confirmed the formation of CCZ crystal structure. The photoluminescence spectra of CCZ, shows blue and green emissions at 499 nm and 519 nm, respectively, due to the active radicals generated in the nanomaterial, which are responsible for the associated antimicrobial and anticancer activities. The antibacterial activity of the CCZ, performed against methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli), showed a greater antibacterial effect than the commercial amoxicillin. The cytotoxic effect of the CCZ nanomaterial was examined in cultured (MCF-7) human breast cancer cells. An IC50 concentration value of 43.53 µg/mL, was recorded when evaluated after 24 h of CCZ with the MCF-7 cell line. From this study, it is believed that CCZ is a highly promising nanomaterial, which will be suitable for advanced clinical applications.

Parametric Analysis of Electrical Conductivity of Polymer-Composites.

The problem associated with mixtures of fillers and polymers is that they result in mechanical degradation of the material (polymer) as the filler content increases. This problem will increase the weight of the material and manufacturing cost. For this reason, experimentation on the electrical conductivities of the polymer-composites (PCs) is not enough to research their electrical properties; models have to be adopted to solve the encountered challenges. Hitherto, several models by previous researchers have been developed and proposed, with each utilizing different design parameters. It is imperative to carry out analysis on these models so that the suitable one is identified. This paper indeed carried out a comprehensive parametric analysis on the existing electrical conductivity models for polymer composites. The analysis involves identification of the parameters that best predict the electrical conductivity of polymer composites for energy storage, viz: (batteries and capacitor), sensors, electronic device components, fuel cell electrodes, automotive, medical instrumentation, cathode scanners, solar cell, and military surveillance gadgets applications. The analysis showed that the existing models lack sufficient parametric ability to determine accurately the electrical conductivity of polymer-composites.