Magnetorheological fluids (MRFs) is a smart fluid system that exhibits swift and reversible alterations in their rheological characteristics when exposed to an external magnetic field. MRFs are used for applications in various areas, including automotive systems, robotics, aerospace, and civil engineering. The performance of MRFs depends on the behavior of the dispersed magnetic particles, necessitating thoughtful consideration of particle traits to optimize fluid performance. Carbonyl Iron Powders (CIPs), high purity iron (>98%) reduced from penta carbonyl iron, are widely employed in MRFs due to their exceptional magnetic characteristics. Nevertheless, the innate surfaces of CIPs tend to conglomerate, leading to compromises in fluid stability and rheological performance. To overcome the challenges, an intensive research has been devoted to advancing surface modification techniques that augment the dispersion, stability, and overall functionality of MRFs based on CIPs. This review describes the comprehensive approach to surface modification of CIPs for highly stable MRFs. We discuss the various surface modification methodologies that have been explored to optimize the behavior of carbonyl iron-based MRFs. Coating techniques, surfactant functionalization, magnetic coatings, and emerging approaches such as nanocoatings and electrochemical modification are also summarized. Moreover, insights into potential applications and future prospects of these modified MRFs are provided.

A one dimensional isothermal model is proposed by modelling the kinetics of methanol transport at anode flow channel (AFC), membrane and cathode catalyst layer of direct methanol fuel cell (DMFC). Analytical model is proposed to predict methanol cross-over rate through the electrolyte membrane and cell performance. The model presented in this paper considered methanol diffusion and electrochemical oxidation at the anode and cathode channels. The analytical solution of the proposed model was simulated in a MATLAB environment to obtain the polarization curve and leakage current. The effect of methanol concentration on cell voltage and leakage current is studied. The methanol cross-over has the significant impact on cell performance. The presented model predicts higher leakage current with the increase of methanol feed concentration. The cell performance was predicted at 70°C and various methanol feed concentration. The proposed model was validated with the experimental polarization curve of active DMFC.

Resin composites are commonly applied as the material for dental restoration. Wear of these materials is a major issue. In this study specimens made of dental composite materials were subjected to an in-vitro test in a pin-on-disc tribometer. Four different dental composite materials applied in the experiment were soaked in a solution of chewing tobacco for certain days before being removed and put through a wear test. Subsequently, four different machine learning (ML) algorithms (AdaBoost, CatBoost, Gradient Boosting, Random Forest) were implemented for developing models for the prediction of wear of dental materials. AdaBoost, CatBoost, Gradient Boosting and Random Forest model show an MAE of 0.7011, 0.0773, 0.0771 and 0.2199. AdaBoost model performs poorly in comparison to other models.

The acoustic emission monitoring with artificial neural networks predicts the ultimate strength of glass/epoxy composite laminates using Acoustic Emission Data. The ultimate loads of all the specimens were used to characterise the emission of hits during failure modes. The six layered glass fiber laminates were prepared (in woven mat form) with epoxy as the binding medium by hand lay-up technique. At room temperature, with a pressure of 30 kg/cm2, the laminates were cured. The laminates of standard dimensions as per ASTM D3039 for the tensile test were cut from the lamina. The Acoustic Emission (AE) test was conducted on these specimens under the load of uni-axial tension in the 10 Ton capacity Universal Testing Machine (UTM). In the monitoring process, acoustic emission parameters such as hits, counts, energy, duration, Root Mean Square (RMS) Value and amplitude were recorded. The RMS Values corresponding to the amplitude ranges from tensile test were used to characterise the failure load of all the similar glass-epoxy composite specimens.

In current research work, we have studied the blending effect of non-mulberry silk fibroin (10% weight/volume basis) and gelatin (20% weight/volume basis) in formic acid. Several blends as SF10G0, SF2G8, SF3G7, SF5G5 and SF0G10 have been made and their rheological behaviour was investigated. The blend solutions were subjected to a steady shear rheological study in the variety of range of shear rates, namely 0.01–500 sec-1 and the viscosities of blend solutions were noticed to decrease in comparison to pure silk solution. The frequency sweep was employed in dynamic rheological tests to determine complex viscosity of these solutions from range of angular sweep 0.1–100 rad/sec. The consistent shear-thinning behaviour was noted for all the blends. The difference in numerical values of shear and complex viscosities indicated disobedience of Cox-Merz rule. Such analysis can be utilised for tailoring the properties of solution prior to processing them to create a versatile range of materials.

The organic fluorine modified/containing cationic acrylic resin is prepared via solution polymerization technique using hexafluorobutyl methacrylate (HFMA) along with butyl acrylate (BA), methyl methacrylate (MMA), styrene (St), dimethylaminoethyl methacrylate (DMAEMA) and hydroxy propyl methacrylate (HPMA) as the comonomers, proprylene glycol monomethyl ether (PGME) as the solvent, and 2, 2-Azo-bis-iso-butyronitrile (AIBN) as the initiator. The synthesized resin in which fluorine atom is introduced into the polymer chains. The cathodic electrodeposition (CED) coatings were prepared by mixing the synthesized resin and blocked isocyanate. The influence of the amount of organic fluorine on the resin and the resultant CED coatings is investigated in detail. In view of the appearance and hydrophobicity of the film, the optimum amount of organic fluorine is obtained, which is 12.0%. The hydrophobicity and the acid and alkaline resistance properties of the coating film are improved when the organic fluorine monomer is introduced into the resin.

The present study has explored the adsorption properties of polypyrrole-based adsorbents (polypyrrole and polypyrrole-polyethyleneimine composite) as novel conducting polymers in adsorbing methyl orange (MO) (an anionic dye) effectively from aqueous solution. The adsorption characteristics of the prepared polymer-based adsorbents were characterized by BET, FTIR, FESEM, and XRD methods. The effectiveness of PPy-based adsorbents for MO dye adsorption was examined using the batch adsorption method. Different parameters were changed during the adsorption process, including contact time, solution pH, and adsorbent dosage. The highest BET surface area of the PPy-PEI composite was found to be 11.85 m2/g, which is much greater than that of the pristine PPy having 8.54 m2/g. The dye removal performance was obtained to be 79.1 % and 98.8 %, by pristine PPy adsorbent and PPy-PEI adsorbent, respectively, at the optimum condition of pH 3, adsorbent dosage of 0.1 g with a contact time of 120 minutes. The Langmuir isotherm model explained the adsorption data better than the Freundlich isotherm model, and the pseudo-second-order model adequately explained the kinetic data for both the adsorbents. The regeneration investigation demonstrated the effectiveness of reusing PPy-PEI composite adsorbents for up to three successive adsorption-desorption cycles. The prepared PPy-PEI composite adsorbents appeared to be very much effective in removing anionic dyes from aqueous solutions.

The exoskeleton of marine shrimp contains a natural, biocompatible polymer chitin, which is dumped as a waste. The study proposes the sustainable single-pot-extraction of chitosan from the waste and its use in the fabrication of wound-dressings, and thus leverage its piezoelectric, antioxidant, hypoglycaemic and medicinal properties in wound-healing. The Fourier transform infrared spectrum revealed that marine chitosan contains functional groups with N-O, O-H, and CO stretching. Scanning electron micrographs demonstrated the spherical and mesoporous structures of the extracted chitosan. X-ray diffraction analysis showed a semi-crystalline phase of chitosan particles with a mean size of 28.9 nm. The film prepared with marine shrimp chitosanpolyvinyl alcohol (PVA) composite, and used as a wound dressing exhibited significant wound healing properties with a regeneration efficiency of 78% in 8 days in Wistar albino rats. The wound healing efficiency was enhanced by the addition of cost effective, non-toxic/environmentally friendly silver nanoparticles (AgNPs) synthesized from Rumex acetosa (sorrel) plant extracts and electrospinning of the nanofibrous composites of chitosan/PVA/AgNPs with high antibacterial, antioxidant and wound healing capacity of 96% in 8 days. Thus, the current study supports the use of a natural piezoelectric chitosan polymer as a wound dressing material, either in film or nanofiber, for normal as well as diabetic wounds.

Bisphenol-C epoxy crotonate resin was synthesized by reacting 8.09g epoxy resin of bisphenol- C, and 2.15g crotonic acid using 25 mL 1,4-dioxane as a solvent, and 1 mL triethylamine as a catalyst at reflux temperature for 1-6 h. Solid epoxy crotonate (ECCR) is highly soluble in common organic solvents. ECCR was characterized by its acid (24.5-1.5 mg KOH/g) and hydroxyl (504.5-678.4 mg KOH/g) values. The structure of ECCR is supported by FTIR and 1HNMR spectroscopic methods. A DSC endothermic transition at 229oC indicated melting followed by thermal polymerization of ECCR. ECCR is thermally stable up to 320oC and follows three-step degradation kinetics. The first step followed first-order degradation kinetics, while the second and third steps followed one-half-order degradation kinetics. High values of kinetic parameters suggested the rigid nature of the crosslinked resin. Jute-, Glass- and Jute-natural fiber-ECCR composites showed moderate tensile strength, flexural strength, electric strength, and volume resistivity due to the rigid nature and poor interfacial adhesion of the composites. J-ECCR and G-ECCR composites showed high water absorption tendency and excellent hydrolytic stability against water, 10% aq. HCl and 10% aq. NaCl and even in boiling water. Mechanical and electrical properties and water absorption tendency of the composites indicated their usefulness as low load-bearing housing and insulating materials. They can also be utilized in harsh environmental conditions.

Tetramethylurea (TMU) is a good solvent for organic substances and has received little attention as compared to other solvents. The TMU is a polar solution and is one of the molecules with an amphiphilic character. In the present work, an attempt has been made to use TMU as an additive in the preparation of nanofiltration membranes to improve the hydrophilicity of the membrane. The polysulfone membrane has been modified by incorporating different concentrations of TMU (0, 0.5, and 1 wt.%) in order to check the rejection of atrazine in water. This study aim is to optimize the conditions to enhance the flux and the rejection of atrazine. It was observed that the rejection of atrazine was enhanced when feed pH changed to acidic and with increasing the evaporation time. The prepared membranes were subjected to different analyses, such as contact angle measurement, FTIR, porosity, and mean pore size. The effect of the coagulation bath, evaporation time, and pH on the atrazine rejection was also studied. Membrane with 0.5 wt.% TMU shows maximum rejection of atrazine at the operating pressure of 15 kgf/cm2.