Effect of lignocellulosic corn stalk on mechanical, physical, and thermal properties of injection moulded low density polyethylene composites: An approach towards a circular economy

Escalating concern over global warming, which is mostly associated with deforestation, has led to the development of new classes of materials that can replace wood and better utilise natural resources. Presently, waste is a significant factor in recycling. In this regard, one of the leading contributors to waste is agricultural waste, which includes dried branches, leaves of trees, plants, and other organic materials. In the current study, waste from corn agriculture was utilised as a potential reinforcement for the fabrication of corn stalk-low density polyethylene (CS-LDPE) composites via an injection moulding technique at 170 °C. The different parameters were assessed to develop composites using CS, including physico-chemical, macromolecular, mineralogical, elemental, and morphological analysis. The amount of corn stalk (CS) was varied from 10 to 50 wt% with respect to the polymer. The mechanical, physical and thermal performance of the composites was examined. The density and water absorption of the composites were found to remain within the ranges of 1.00-1.11 g/cm3 and 0.22-1.01 %, respectively, whereas these parameters increased as the proportion of CS increased. The thermal conductivity decreases with the addition of CS from 0.36964 ± 0.020 to 0.22388 ± 0.002 W/mK. It was observed that adding CS to the composites increased their tensile and flexural properties, but decreased their impact strength. The maximum flexural strength of 14.40 ± 1.558 MPa, flexural modulus of 752.53 ± 180.409 MPa, tensile strength of 10.49 ± 0.946 MPa and tensile modulus of 539.79 ± 91.044 MPa were observed with a 50 % CS content. The results suggest that these materials have considerable potential to serve as a cost-effective substitute for the conventional lignocellulosic fillers in the manufacturing of wood-plastic composites.

Extremely Reduced Dielectric Constant and Band Gap Enhancement in Few-Layered Tungsten Disulfide Nanosheets

Highly crystalline few-layered tungsten disulfide (WS₂) nanosheets were synthesized via a cost-effective, low-temperature hydrothermal route. X-ray diffraction and HR-TEM analysis confirmed the formation of hexagonal nanosheets with thickness of ∼6-8 nm. Raman analysis and AFM results confirmed the few-layered 2H phase of WS₂ nanosheets. The UV-vis study shows absorption peaks at 219 and 271 nm with large band gap value of ∼3.12 eV for WS₂ nanosheets. Surprisingly, WS₂ nanosheets show a dielectric constant of approximately ε' ≈ 5245, whereas bulk WS₂ material exhibits a dielectric constant of 7482373. An almost 1426-fold decrease in the value of dielectric constant for the WS₂ nanosheet is observed. Such an extreme reduction in dielectric constant and observance of large band gap in WS₂ nanosheet were observed for the first time. The present study reveals the excellent and unusual optical and dielectric properties for their potential application in optoelectronic, dielectric, solar, phosphor, and various nanoelectronic devices.

Advances in industrial prospective of cellulosic macromolecules enriched banana biofibre resources: A review

Biological macromolecules enriched resources are rapidly emerging as sustainable, cost effective and environmental friendly materials for several industrial applications. Among different biological macromolecules enriched resources, banana fibres are one of the unexplored high potential bio-resources. Compared to various natural fibres such as jute, coir, palm etc., the banana fibres exhibits a better tensile strength i.e. 458 MPa with 17.14 GPa tensile modulus. Traditionally used petroleum based synthetic fibres have been proven to be toxic, non-biodegradable and energy intensive for manufacturing. Cellulosic banana fibres are potential engineering materials having considerable scope to be used as an environmental friendly reinforcing element for manufacturing of polymer based green materials. This paper summarizes the world scenario of current production of biological macromolecules rich banana residues and fibres; major user's of banana fibres. The quality and quantity of biological macromolecules especially the cellulose, hemicellulose, lignin, wax, engineering and mechanical properties of banana biofibre resources are reported and discussed. Subsequently, the findings of the recent research on bio resource composites, materials performance and opportunities have been discussed which would be a real challenge for the tomorrow world to enhance the livelihood environmental friendly advancement.

Jarosite characteristics and its utilisation potentials

During metallic zinc extraction from zinc sulphide or sulphide ore, huge quantity of jarosite is being released universally as solid residues. The jarosite mainly contains iron, sulphur, zinc, calcium, lead, cadmium and aluminium. Jarosite released from such industrial process is complex and its quality and quantity make the task more complex for safe disposal. Apart from water contamination, jarosite already accumulated and its increasing annual production is a major source of pollution for surrounding environment including soil, vegetation and aquatic life and hence its disposal leads to major concern because of the stringent environmental protection regulations. An attempt was made to evaluate the characteristics of Indian jarosite with an objectives to understand its potentials for recycling and utilising as raw materials for developing value added products. Sand and Coal Combustion Residues (CCRs) was used as an admixture to attain good workability and detoxify the toxic substance in the jarosite. Result revealed that jarosite is silty clay loam in texture having 63.48% silt sized and 32.35% clay sized particles. The particle size of jarosite (D90=16.21+/-0.20 microm) is finer than the CCRs (D90=19.72+/-0.18 microm). The jarosite is nonuniform in structure and shape as compared to the CCRs having spherical, hollow shaped and some of them are cenosphere in nature. The major mineral phase of jarosite is Potassium Iron Sulphate Hydroxide {KFe3(SO4)2(OH)6}and Iron Sulphate Hydrate {2 Fe2O3SO3 x 5 H2O}. In CCRs the dominant phases are quartz {SiO2}, mullite {3 Al2O3 x 2 SiO2} and hematite {Fe2O3}. The high electrical conductivity of jarosite (13.26+/-0.437 dS/m) indicates that the presence of cations and anions are predominant over CCRs (0.498+/-0.007 dS/m). The major portion of jarosite consists of iron (23.66+/-0.18%), sulphur (12.23+/-0.2%) and zinc (8.243+/-0.075%). But CCRs main constituents are silicon (27.41+/-0.74%), aluminium (15.167+/-0.376%) and iron (4.447+/-0.69%). The other constituents such as calcium, aluminium, silicon, lead, and manganese are also present in the range of 0.5 to 5%. Heavy metals such as copper, chromium, and cadmium are found higher in jarosite as compared to the CCRs. The statistically designed experimental trials revealed that the density, water absorption capacity and compressive strength of fired jarosite bricks are 1.51 gm/cm3, 17.46% and 43.4 kg/cm2 respectively with jarosite sand mixture in the ratio of 3:1 indicating the potentials in developing building materials.

Effect of cationic amphiphilic drugs on the hydrolysis of acidic and neutral phospholipids by liver lysosomal phospholipase A

Rat liver lysosomal phospholipase A hydrolyzes both acidic and neutral phospholipids. Numerous cationic amphiphilic drugs including imipramine, propranolol, 4,4'-bis(diethylaminoethoxy)-alpha, beta- diethyldiphenylethane and chloropromazine inhibit phospholipase A. Cationic amphiphilic drugs bind readily to acidic phospholipids but much less readily to neutral phospholipids. Formation of drug-lipid complexes is thought to be an important mechanism involved in the inhibition of lysosomal phospholipases. Therefore, we studied the effects of four cationic amphiphilic inhibitors on lysosomal phospholipase A using one acidic and two neutral phospholipid substrates. The concentration of the drugs required to produce 50% inhibition was much higher when phosphatidylinositol was used as substrate. The degradation of phosphatidylethanolamine and phosphatidylcholine was more readily inhibited by these agents than that of phosphatidylinositol. In drug-induced lipidosis, the predominance of acidic phospholipids may be due to redirection of phospholipid metabolism towards the formation of acidic phospholipids with a resultant increased delivery of these lipids to lysosomes. Based on our results, it does not appear to be due to decreased enzymatic hydrolysis of drug-acidic phospholipid complexes, at least when pure phospholipid substrates are used. Lysosomal storage of both acidic and neutral phospholipids appears to be caused by inhibition of lysosomal phospholipase action in view of the probable high intralysosomal levels of these agents.