Blend Composition Research Articles

Green blend nanocomposites developed from waste sericin, polyvinyl alcohol and boehmite for flexible electronic devices

The present research article demonstrates the dispersion of boehmite (BHM) nanoparticles into sericin (SER) from silk industry waste with polyvinyl alcohol (PVA) to enhance the optical, mechanical, thermal and electrical characteristics of PVA/SER blend nanocomposites prepared by a simple green synthesis. Techniques such as Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV visible spectroscopy, field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were carried out for the characterization of the prepared composites. XRD revealed the increased crystallinity of the polymer blend by the reinforcement of BHM. The existence of intermolecular interactions in the blend composite was confirmed by FTIR and UV spectroscopy. The optical bandgap energy of the biopolymer blend decreases with the inclusion of BHM. The SEM and HR-TEM confirmed the homogeneous dispersion of BHM in the blend at 5 wt% loading. The glass transition temperature and thermal stability of the blend nanocomposites were significantly improved by the inclusion of BHM was deduced from DSC and TGA. The dielectric constant and AC conductivity were remarkably increased with the reinforcement of nanoparticles. The activation energy obtained from AC conductivity decreased with temperature. The mechanical properties of the blend nanocomposites (hardness, tensile strength and Young's modulus) were greatly increased in presence of BHM. The 5 wt% sample has the highest tensile strength, Young's modulus, dielectric constant, AC conductivity and optical properties, allowing it to be used to make optoelectronic devices with better charge-storing capacity and flexible-type electrochemical gadgets.

Fatigue behavior of polymethyl methacrylate/acrylonitrile butadiene styrene blends including blend composition, stress ratio, frequency, and holding pressure effects

In engineering applications, polymer materials are expected to exhibit superior fatigue life and balanced mechanical properties as essential performance criteria. The blending method is an important alternative in improving the performance criteria of ABS polymer in service. Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), and Dynamic Mechanical Analysis (DMA) methods were used for characterization. The effects of the PMMA fraction on the mechanical and fatigue behavior of PMMA/ABS blends were investigated by tensile and fatigue tests. Also, the influence of blend composition, stress amplitudes, stress ratio, holding pressure, and loading frequency on fatigue life is considered. The study improved yield strength, tensile strength, and elongation at break values of blends compared to ABS. In addition, 115 % and 75 % improvements were achieved in fatigue cycles at high and low-stress amplitudes with blends, respectively, for tension/tension loading. Similar improvements were obtained for fully reverse loading at 218 %. Thus, it was determined that the PMMA/ABS blend exhibited superior fatigue life in both tension/tension and fully reverse loading situations. Finally, it has been understood that PMMA/ABS blends can be designed to have mechanical properties and fatigue life behavior that can meet different requirements in conditions for engineering applications.

Facile synthesis of carboxymethyl cellulose from Indonesia's coconut fiber cellulose for bioplastics applications

AbstractCoconut fibers contain many lignocellulosic components; therefore, they have the potential to be used as cellulose‐based materials. This study aims to synthesize carboxymethyl cellulose (CMC) for bioplastic applications from coconut fiber cellulose obtained from South Tangerang, Indonesia. The isolation of cellulose was conducted in two key stages: alkaline treatment using a delignification reactor and bleaching with hydrogen peroxide (H2O2). The facile synthesis of CMC involved two important steps: alkaline treatment and carboxymethylation of isolated cellulose. The yield of cellulose isolated from coconut fiber was 16.39% for biomass and 64.84% for delignification products. The cellulose produced exhibited a crystallinity index (C.I.) of 89%. The yield of CMC was 14.67%, with a C.I. was 56.66%. The CMC obtained was categorized as having a medium molecular weight of 249,048 Da with a polymerization degree of 1046. Cellulose starts to decompose at a temperature interval of 292.05–381.45°C, whereas CMC decomposes at a lower temperature interval of 245.42–299.73°C. Thermochemical calculations were conducted by using the density functional theory (DFT), confirming a spontaneous reaction with a Gibbs free energy of −5.25 kJ mol−1. Bioplastics were fabricated in two stages: blending with carboxymethyl chitosan (CMChi) and plasticizing with glycerol. The addition of CMCh increased the C.I. and tensile strength, while the addition of glycerol to CMC/CMChi (80/20) blend‐based bioplastic reduced the C.I. and tensile strength, but enhanced the relative contact angle.Highlights Cellulose was isolated from coconut fibers through a two‐stage process involving delignification and bleaching; Carboxymethyl cellulose was synthesized by reacting the cellulose of coconut fibers with monochloroacetic acid in isopropanol with NaOH as the catayst; The optimum condition for achieving the highest elongation at break among the blending compositions was found in the CMC/CMChi (80/20) blend bioplastic; Adding up to 30 wt% glycerol decreased the tensile strength and increased the elongation at break; The addition of glycerol enhanced the hydrophobic properties of CMC/CMCh blend‐based bioplastics.

The effect of waste tire oil and pertamina dex oil blends on compression ignition engine performance

Abstract The improper disposal of waste tires is widely recognized as a significant environmental hazard, posing risks to both human health and safety. To address this issue, an effective approach is the transformation of waste tire into an essential product, namely Waste Tire Oil (WTO). Therefore, this study aimed to investigate the influence of blending WTO and Pertamina Dex oil on the performance of compression ignition (CI) engines. The Yanmar TF 65 R diesel engine, featuring a single cylinder, 6.5 HP of power, and a net output of 2200 rpm, was used for the experiment. The analysis was performed on various compositions of WTO and Pertamina Dex oil blends. Specifically, WTO-10 which indicated the addition of 10% volume percentage of WTO to Pertamina Dex oil, WTO-20, and WTO-30, were examined. WTO-10 indicates that a 10% volume percentage of waste tire oil was added to Pertamina Dex oil. Subsequently, the power, specific fuel consumption, and thermal efficiency of the CI engine were analyzed. The results showed that the output power significantly increased with high rotation speed. It was also discovered that adding WTO to Pertamina Dex oil did not significantly reduce CI engine power at the same running speed. Furthermore, engine speeds ranging from 1500 to 1900 rpm at a lower rate indicated a decrease in specific fuel consumption as engine speed increased. In contrast, the range 2100 rpm to 2500 rpm showed an increase in specific fuel consumption, indicating a decrease in thermal efficiency by approximately 5.6%. Based on the results of this research was suggested that WTO potensial added to pertamina dex oil as a fuel for diesel engine withoud any modification.

Hybrid Biopellets Characterization of Gamal Wood (Gliricidia sepium) and Robusta Coffee Husk at Various Compositions

Biopellets from gamal wood (Gliricidia sepium) as a biomass energy resource could be an alternative to replace fossil fuels due to having met standards based on moisture content, ash content, fixed carbon, calorific value, and density. Unfortunately, they still had high levels of volatile matter. Robusta coffee husk was a material with high nitrogen content, which is suspected of being able to bind aromatic substances in volatile organic compounds. This study aims to evaluate the quality of biopellets and determine the optimum composition of the biopellets from gamal wood and coffee husk. The blended composition of gamal wood and coffee husk biopellets studied were 100:0, 75:25, 50:50, 25:75, and 0:100. The biopellets were manufactured using the material size of 40-60 mesh with a pressure of 173.51 MPa. The best biopellet was produced in the composition of 75% gamal wood and 25% coffee husk, with a density of 0.85 g/cm3, moisture content of 8.03%, ash content of 3.92%, volatile substances of 78.01%, fixed carbon of 18.07%, and calorific value of 4,176 cal/g. The biopellet quality met the standards of SNI 8021:2014 and EN 14061-2, except for ash content. Adding coffee husk reduced gamal wood biopellet’s volatile matter, increasing the fixed carbon and density of gamal wood biopellets. Keywords: alkali immersion, bamboo, bio-composite, oriented strand board, pre-treatment

Effect of polycarbonate (PC) content on the mechanical properties, morphology and transesterification mechanism of PBT/PC immiscible blends

AbstractThis study focuses on the experimental investigation of the mechanical properties of PBT/PC blends with varying compositions. The studied mechanical properties include tensile strength, elongation, tensile modulus, impact strength, and Shore hardness of PBT/PC blends with different PC contents. PBT, characterized by its semi‐crystalline and tough nature, contrasts with PC, known for its impact resistance and hardness. Achieving an optimal blend composition proves to be crucial for attaining the best combination of these properties. The tensile strength of the PBT/PC 30/70 blend increased by approximately 24%, with Shore hardness also experienced a 12% enhancement compared to pure PBT. This improvement is attributed to the presence of PC segments in the blend structure. Conversely, an increase in PC content led to the elongation and impact strength of the blends peaking in the PBT/PC 70/30 blend. Notably, the impact strength of the PBT/PC blend with 30% PC increased by about three times compared to PBT and 18% more than pure PC. Scanning Electron Microscopy (SEM) analysis revealed that PBT and PC segments disperse at lower PC content, while at higher content, phase separation becomes prominent. Fourier Transform Infrared Spectroscopy (FTIR) analysis indicates direct transesterification between PBT and PC, resulting in the formation of a long‐chain blend structure with random copolymer blocks. The transesterification mechanism is also supported by Differential Scanning Calorimetry (DSC) results, wherein a reduction in the crystallization temperature (Tc) and an increase in the glass transition temperature (Tg) is observed. The study concludes that the volume of these segments and their bonding play a decisive role in determining the mechanical properties. The bonding mechanism elucidated through FTIR and SEM provides valuable insights into the fabrication and property engineering of PBT/PC blends.

Enhancing material toughness by introducing defects

Achieving high toughness is still very challenging in material science. Defect engineering offers novel avenues for making tough materials by finely adjusting microstructures, rather than relying on composite blends of different substances. However, how the introducing artificial defects affect the mechanical performances of materials and what factors influence the toughening effects of artificial defects remain poorly understood. In this study, we establish a theoretical framework that accounts for the stochastic distribution of initial defects in the materials and the controlled introduction of artificial defects. We find that the material becomes more brittle as the maximum initial defect increases. However, judiciously introducing artificial defects renders more regions in the materials to enter plastic deformation. Thus, materials can effectively absorb more energy during fracture, thereby enhancing their overall fracture toughness, no matter whether they are originally brittle or ductile. We further present the phase diagrams that elucidate the optimal conditions for improved material properties by introducing artificial defects. The predominance of defect-mediated toughening mechanisms broadens the materials design space and facilitates cost control and recycling.

Advances in Polyvinyl Alcohol-Based Membranes for Fuel Cells: A Comprehensive Review on Types, Synthesis, Modifications, and Performance Optimization.

Fuel cell technology is at the forefront of sustainable energy solutions, and polyvinyl alcohol (PVA) membranes play an important role in improving performance. This article thoroughly investigates the various varieties of PVA membranes, their production processes, and the numerous modification tactics used to solve inherent problems. Various methods were investigated, including chemical changes, composite blending, and the introduction of nanocomposites. The factors impacting PVA membranes, such as proton conductivity, thermal stability, and selectivity, were investigated to provide comprehensive knowledge. By combining various research threads, this review aims to completely investigate the current state of PVA membranes in fuel cell applications, providing significant insights for both academic researchers and industry practitioners interested in efficient and sustainable energy conversion technologies. The transition from traditional materials such as Nafion to PVA membranes has been prompted by limitations associated with the former, such as complex synthesis procedures, reduced ionic conductivity at elevated temperatures, and prohibitively high costs, which have hampered their widespread adoption. As a result, modern research efforts are increasingly focused on the creation of alternative membranes that can compete with conventional technical efficacy and economic viability in the context of fuel cell technologies.

Chemical Composition, Microbiological and Sensory Qualities of Banana Based Complementary Diets Fortified with African Breadfruit Seed and Carrot Flours

About the age of six months, an infant requires more nutrients and energy than those provided by the breast milk, and complementary diets are therefore introduced to meet those needs. The objective of this study was therefore to develop and evaluate complementary diets from cooking banana, African breadfruit seeds and carrot flour blends. Ratios of cooking banana, African breadfruit seed and carrot flour blends in 90:0:10 as Diet 1, 85:5:10 as Diet 2, 80:10:10 as Diet 3, 75:15:10 as Diet 4 and 70:20:10 as Diet 5, were used for formulation of complementary diets. The flour blends for diet production showed bulk density and gelatinization temperature decreased from 0.98 to 0.65 g/ml and 85.67 to 78.10oC respectively, while swelling and water absorption capacity increased from 268.33 to 295.00% and 208.33 to 243.33% respectively, with increase in African breadfruit seed flour in the composite blends. Phytate (1.25 – 11.03 mg/100g) and trypsin inhibitor activities (1.05 – 1.17 TIU/100g) increased with increasing African breadfruit flour supplementations. Proximate composition of diets showed increased protein (2.16 – 18.47%), fat (1.81 – 2.23%), ash (2.42 – 2.96 %) and decreased carbohydrate (73.14 – 89.80%). Iron and calcium content of Diets increased from 14.11 – 19.23mg/100g and 28.24 – 43.23 mg/100g, while magnesium decreased from 6.24 – 8.25mg/100g respectively with increasing African breadfruit flour. Vitamin A and C decreased from 13.09 to 9.16 and 0.98 – 0.75mg/100g respectively. Microbial quality of all Diets developed were within the acceptable limit of 103 cfu/g for both total bacterial (TBC) and total fungal count (TFC). Diet 3 (80:10:10) was most accepted in sensory qualities. Complementary diets produced with 80% cooking banana, 10% African breadfruit seed and 10% carrot flour blends could help fill the gaps, when transitioning from breast milk to family diet, to provide the essential nutrients and energy required for infant’s activity, optimum growth and development.

3D‐printed PLA/PMMA polymer composites: A consolidated feasible characteristic investigation for dental applications

AbstractThis research article focused on the blending of poly(lactic acid)/poly(methyl methacrylate) (PLA/PMMA) polymer materials to overcome PLA's inherent weaknesses, such as low glass transition temperature, brittleness, and lack of melt strength. Consolidated feasible characteristic investigations, such as mechanical, thermal, and aging behavior, were carried out for PLA/PMMA blended polymer materials. Initially, the miscibility of PLA/PMMA blend filaments was prepared at various blend ratios (91/9, 82/18, and 73/27) and samples were printed by fused deposition modeling (FDM). Differential scanning calorimetry (DSC) and Fourier infrared spectroscopy (FTIR) analysis have been utilized to evaluate the glass transition temperature (Tg) and intermolecular interaction, respectively, on blended polymer materials. Experimental tensile, compression, and flexural strength testing were performed on neat polymers and blended polymer composites. Compared to neat PLA materials, blended composites had 13.24% and 19.07% higher flexural and compression strengths. Besides, the interfacial interaction of neat and blended polymers has been done using dynamic mechanical analysis (DMA). Furthermore, Tg, storage modulus, and aging behavior of blended polymer materials have significantly improved over neat PLA materials. Altogether, the development of PMMA/PLA blends as sustainable biomaterials for dental applications aligns with environmental concerns and the need for biocompatible materials in dentistry.Highlights Blending of PLA and PMMA helps mitigate the inherent constraints of PLA. Blended composites exhibited greater compressive and flexural strengths. Better glass transition temperature and intermolecular interaction. Excellent thermal stability and water aging imply viable dental biomaterials.

Effects of Recycled Polyethylene on Natural Rubber Composite Blends Filled with Aluminum Trihydroxide and Polyurethane Waste: Mechanical and Dynamic Mechanical Properties, Flammability.

This research studies natural rubber (NR) composite blends prepared with recycled polyethylene (PE), polyurethane waste (PU), silica (SiO2), and aluminum trihydroxide (ATH) under the proper mixing conditions using an internal mixer and a two-roll mill. The mechanical, impact, dynamic mechanical, and thermal properties, together with flammability, were investigated. NR/PU composites filled with a specific SiO2/ATH concentration resulted in excellent flame-retardant properties without using PE. Adding PE causes poor flammability, while using PU and SiO2 prevents flame extensibility of the composites. In addition, SiO2 and ATH synergistically improved both mechanical and dynamical mechanical properties. This is attributed to the reinforcement of SiO2 particles inside the matrix, whereas the ATH releases water as a flame retardant. The V-0 composites tested with UL-94 showed acceptable heat resistance, strength, and durability, making them suitable for interior and exterior applications in buildings without the lightweight requirement.

Nutritional and bioactive potentials of a powder and a decoction made from Ceylon cinnamon bark, Laurus nobilis leaves, and Curcuma longa Linn rhizome

The blends of Ceylon cinnamon bark (F1), Laurus nobilis leave (F2), and Curcuma longa rhizome (F3) powders are recommended by therapists, as are their decoction, for fighting chronic diseases. This study aimed to assess the nutritional and bioactive potential of a powder blend made from those three plant food matrices and the form of consumption with the most beneficial antioxidant potential. Ceylon cinnamon dry bark, Laurus nobilis fresh leaves, and Curcuma longa fresh rhizome were purchased and processed directly into powders. A substitution plan of Cinnamon powder involving three powder blends (F4, F5, F6) and a decoction marketed had been retained. The proximate composition, nutrient density, bioactive compounds, and antioxidant activity of the powder blends and decoction (bioactive compounds and antioxidant activity) were determined. F1 powder, presents the best characteristics in terms of protein content, nutrient density, and bioactive compounds. The powder blend F6, composed of 50 % Ceylon cinnamon bark, 30 % Laurus nobilis leaves and 20 % Curcuma longa rhizome, had higher contents of total protein (14.85 ± 0.37 g/100 g DM), crude fiber (32. 49 ± 0.90 g/100 g DM), total polyphenols (268.50 ± 2.00 mg GAE/g DM), total flavonoids (55.09 ± 1.01 mg QE/g DM), and a higher nutrient density in iron (1.03 mg/100 Kcal) and zinc (1.61 mg/100 Kcal). The decoction obtained from the F6 powder blend after 5 min of boiling, had high soluble bioactive compounds contents: polyphenol (24.5 ± 1.07 mg GAE/g DM), flavonoids (0.25 ± 0.01 mg QE/g DM), and condensed tannins (0.09 ± 0.00 mg CE/g DM). An antioxidant activity whose main basic mechanism is the reduction of Fe3+ to Fe2+, higher (74.94 % close to vitamin C) than that of the blend itself (65.20 % close to vitamin C). The decoction derived from the boiling of the F6 powder blend represents its most advantageous form of consumption.

Fibre Blend and Web Arrangement for Optimized Dust-Holding, Hydrophobic, and Thermal Properties of Needle-Punched Nonwovens

PM2.5 filters with hydrophobicity and thermal resistance are preferable for automobile cabins, engine air intake, and indoor applications, safeguarding against moisture ingress, microbial growth, and temperature fluctuations, and ensuring optimal air quality. This study explored the effects of blending five fibres with different web arrangements and fibre blend compositions on needle-punched dust-holding, hydrophobic, and thermal properties. Polyphenylene sulfide (PPS), polypropylene (PP), polyester (PET), polylactic acid (PLA), and polyacrylonitrile (PAN) were blended in different proportions to produce the samples. The method included opening, blending, carding, web laying, and needle punching to produce eight samples with cross-laid, parallel-laid, and pre-needled parallel-laid web configurations. Standard test methods were employed for the characterization. The results showed a dust holding capacity of > 3,423,000 particles/cm2, the highest WCA of 133.12°, and the highest thermal resistance of 0.24255 m2KW−1. Based on the ANOVA analysis, web arrangement and pre-needling did not have a significant impact on the hydrophobicity of the samples. N0, N1, and N2 showed similar high water contact angles (~ 126°), indicating that the hydrophobicity was more affected by the chemistry of the fibre blend than by the web structure. Turkey’s analysis of other samples strengthened this idea. However, they had a substantial impact on the porosity, air permeability, dust-holding capacity, and thermal properties at a P-value ≤ 0.05. The findings provide insightful information regarding the complex interactions among fibre content, web layout, and pre-needling to develop sophisticated needle-punched PM2.5 filters.

Experimental investigation of ternary blends on performance, and emission behaviors of a modified low-heat rejection CI engine

This study investigated the performance, combustion, and emissions of a modified low heat rejection (LHR) diesel engine fueled with a blend of 90 % coconut waste cooking oil (CWCO) biodiesel and 10 % diethyl ether (DEE). The engine combustion chamber components were coated with 300 μm lanthanum-doped partially stabilized zirconia for thermal insulation. Engine testing was performed at varied loads from 0 to 100 % using an eddy current dynamometer. Exhaust emissions, including hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx), and smoke were measured. Compared to conventional diesel, the CWCO-DEE blend showed a 3 % higher brake thermal efficiency of 33.4 % and 2.42 % lower brake-specific fuel consumption at full load. HC, CO, and smoke emissions decreased by 18 % (39 ppm), 11 %, and 19 % at higher loads with the blend. However, NOx emissions increased slightly by 21.2 %. The DEE compensated for CWCO's lower cetane number and viscosity, while the LHR coating enhanced combustion by providing thermal insulation, raising exhaust gas temperatures by 13 %. The improved efficiency and reduced emissions demonstrate the potential of optimized biodiesel-additive blends in conjunction with LHR engine modifications to sustainably utilize inexpensive waste cooking oil feedstocks as renewable diesel replacements. However, further optimization of blend compositions, additives, and coatings is needed to balance performance benefits against possible NOx increases. This study highlights a promising combined approach leveraging engine design and fuel advancements.

Calorimetric investigation on heat release during the disintegration process of pharmaceutical tablets

The compendial USP〈701〉 disintegration test method offers a crucial pass/fail assessment for immediate release tablet disintegration. However, its single end-point approach provides limited insight into underlying mechanisms. This study introduces a novel calorimetric approach, aimed at providing comprehensive process profiles beyond binary outcomes. We developed a novel disintegration reaction calorimeter to monitor the heat release throughout the disintegration process and successfully obtained enthalpy change profiles of placebo tablets with various porosities. The formulation comprised microcrystalline cellulose (MCC), anhydrous lactose, croscarmellose sodium (CCS), and magnesium stearate (MgSt). An abrupt temperature rise was observed after introducing the disintegration medium to tablets, and the relationship between the heat rise time and the tablet’s porosity was investigated. The calorimeter’s sensitivity was sufficient to discern distinct heat changes among individual tablets, and the analysis revealed a direct correlation between the two. Higher porosity corresponded to shorter heat rise time, indicating faster disintegration rates. Additionally, the analysis identified a concurrent endothermic process alongside the anticipated exothermic phenomenon, potentially associated with the dissolution of anhydrous lactose. Since lactose is the only soluble excipient within the blend composition, the endothermic process can be attributed to the absorption of heat as lactose molecules dissolve in water. The findings from this study underscore the potential of utilising calorimetric methods to quantify the wettability of complex compounds and, ultimately, optimise tablet formulations.

Co-pyrolytic investigation of waste bakelite with different thermoplastics using microwave and conventional batch pyrolysis reactor

Bakelite, a thermosetting plastic, is harder to recycle as compared to than thermoplastic polymers through thermal method due to its inherent property to harden on application of heat. This study co-pyrolyzes waste bakelite with polypropylene (PP), high-density polyethylene (HDPE), polystyrene (PS), and polymethyl methacrylate (PMMA) in a conventional semi-batch pyrolysis reactor and microwave pyrolysis reactor to determine how the reactor type and thermoplastic blending affect product distribution, yield, and composition of condensable fraction. The blending of thermoplastics and pyrolysis reactor types greatly affects product distribution. Bakelite, on pyrolysis, produces 39.12 wt% condensable product, which increased to 45.42 wt%, 58.76 wt%, 61.53 wt%, and 66.76 wt% in conventional pyrolysis and 49.87 wt%, 61.26 wt%, 66.51 wt%, and 72.88 wt% in microwave pyrolysis by blending HDPE, PP, PMMA, and PS respectively. The composition analysis through Gas chromatography-mass spectrometry and Fourier-transformed infrared spectroscopy confirms the formation of alkanes, cycloalkanes, alkenes, cycloalkenes, aromatics, and oxygenated compounds, from both pyrolysis processes. However, their percentage differ significantly in both processes. Microwave-assisted pyrolysis with activated carbon yields superior oil in both quantity and composition compared to conventional pyrolysis, effectively transforming waste plastics into valuable products.

Modification in the Optical and Dielectric Characteristics of Poly (Vinyl Alcohol)/Carboxymethyl Cellulose Blended Polymers Doped with Two Phases Nanocomposites for Application in Optoelectronic and Energy Storage Devices

Nanocomposite films comprised of poly (vinyl alcohol) (PVA) and carboxymethylcellulose (CMC) were fabricated via a solution casting procedure, with the incorporation of (1-x)CuCo2O4/xZnMn2O4. Our research described here was aimed to explore the impact of the (1-x)CuCo2O4/xZnMn2O4 on the structural, optical and electrical features of the PVA/CMC blended polymer, using various techniques. The different phases formed (CuCo2 O4 and/or ZnMn2O4) in (1-x) CuCo2O4/x ZnMn2O4 filler samples were identified applying Rietveld refinement analysis. The structures and morphologies of the PVA/CMC/(1-x)CuCo2O4/xZnMn2O4 blend composites were determined using X-ray diffraction and scanning electron microscopy techniques. Their various linear and nonlinear optical parameters were examined using the diffused reflectance technique. The blended polymer composite with x = 0.1 displayed the highest absorbance. The transmittance of the PVA/CMC blend declined from 91 to 69% when it was loaded with a nanocomposite containing 10% ZnMn2O4. The optical band gaps of the doped blend composites had their lowest values, 5.45 eV for direct transition and (4.83, 2.99, 2.31) eV for the indirect transition, as the blend was loaded with the fillers containing 10 and 15% ZnMn2O4. The study also explored the influence of the (1-x)CuCo2O4/x ZnMn2O4 on the fluorescence spectra and chromaticity diagram of the PVA/CMC blend. The effect of the filler on the complex dielectric constant, complex electric modulus, ac conductivity and electrical storage energy of the host blend was examined. The obtained characteristics imply potential utility of the doped blends in photocatalytic, UV-blocking, UV-filtering, optoelectronic, electrical storage, nonlinear optical and photonic applications.

3D Printing of Composite Radiation Shielding for Broad Spectrum Protection of Electronic Systems.

The miniaturization of satellite systems has compounded the need to protect microelectronic components from damaging radiation. Current approaches to mitigate this damage, such as indiscriminate mass shielding, built-in redundancies, and radiation-hardened electronics, introduce high size, weight, power, and cost penalties that impact the overall performance of the satellite or launch opportunities. Additive manufacturing provides an appealing strategy to deposit radiation shielding only on susceptible components within an electronic assembly. Here, a versatile material platform and process to conformally print customized composite inks at room temperature directly and selectively onto commercial-off-the-shelf electronics is described. The suite of inks uses a flexible styrene-isoprene-styrene block copolymer binder that can be filled with particles of different atomic densities for diverging radiation shielding capabilities. Additionally, the system enables the combination of multiple distinct particle species within the same printed structure. The method can produce graded shielding that offers improved radiation attenuation by tailoring both shield geometry and composition to provide comprehensive protection from a broad range of radiation species. The authors anticipate this alternative to traditional shielding methods will enable the rapid proliferation of the next generation of compact satellite designs.

Optical, Structural, and Dielectric Characteristics of Flexible PVA/PEG/ZnMn2O4/CuCo2O4/x wt % Melanin Blended Polymer Composites

Our research described in the current paper was aimed to alter the optical and dielectric characteristics of polyvinyl alcohol/polyethylene glycol blended polymers by incorporating different quantities of melanin and ZnMn2O4/CuCo2O4 to create flexible blended polymer composites suitable for applications like photocatalysis, capacitors, and different optoelectronic applications. The PVA/PEG/ZnMn2O4/CuCo2O4-x wt % melanin blended polymer composites were created using a casting technique. The structural properties of the fillers and various blends were investigated using an X-ray diffraction technique. A transmittance electron microscope was used to investigate the features of the ZnMn2O4/CuCo2O4. The optical properties of the PVA/PEG/ZnMn2O4/CuCo2O4-x wt % melanin blend composites, which included their linear and nonlinear optical parameters, were analyzed using a diffused reflectance technique. The direct and indirect optical energy gaps attained their lowest values (5.47, 3.22, and 2.97) and (5, 1.18) eV in PVA/PEG/ZnMn2O4/CuCo2O4 blended polymer. The doped blends exhibited superior absorbance efficiency in the UV spectra in both the UVA and UVB regions. In the UV and visible ranges doped blends with 15 and 10 wt % of melanin had the highest refractive index values, respectively. The highest dielectric constant and electric ac conductivity were achieved as the blend was loaded with 5 wt % melanin. The energy density value of the doped blend containing 10% melanin was the highest when compared to other doped melanin polymers. The maximum height electrical potential barrier of each blend was also calculated. The electric modulus was also studied. The intensities of the emission peaks in terms of fluorescence characteristics were reduced as the PVA/PEG blend was loaded with ZnMn2O4/CuCo2O4-x wt % melanin. In conclusion, the PVA/PEG/ZnMn2O4/CuCo2O4-x wt % melanin blended polymer composites are promising hybrid materials for use in a variety of applications.

Mechanical and durability performance of bentonite clay blended cement composites - A Review

Mechanical and durability performance of bentonite clay blended cement composites - A Review