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Polymer nanocomposite is commonly used to develop structural components of space, aircraft, biomedical, sensor, automobile, and battery sector applications. It remarkably substitutes the heavyweight metallic and nonmetallic engineering materials. The machining principles of polymer nanocomposites are intensely different and complex from traditional metals and alloys. The nonhomogeneity, abrasive, and anisotropic nature differs its machining aspect from conventional metallic materials. This investigation aims to execute the CNC drilling of modified nanocomposite using Graphene–carbon (G-C) @ epoxy matrix. The process constraints, namely, cutting speed (S), feed (F), and wt.% of graphene oxide (GO) vary up to three levels and are designed according to the response surface methodology (RSM) array. The nonlinear model is created to predict surface roughness (Ra) and delamination (Fd) on regression analysis. It has been found that the average error for Ra is 0.94% and for Fd it is 3.27%, which is acceptable in model predictions. The metaheuristics-based evolutionary Dragonfly algorithm (DA) evaluated the optimal parametric condition. The optimal setting prediction for the DA is observed as cutting speed (S)-37.68m/min, feed (F)-80mm/min, and wt.% of graphene oxide (GO)-1%. This algorithm demonstrates a higher application potential than the previous efforts in controlling Ra and Fd values. Both the drilling response values are found to be minimized when the cutting speed increases and the feed decreases. The best fitness value for the DA is 1.626 for surface roughness and 5.086 for delamination. This study agreed with the prediction model’s outcomes and the process parameters’ optimal condition. The defects generated during the sample drilling, such as fiber pull out, uncut/burr, and fiber breakage, were examined using FE-SEM analysis. The optimal findings of the DA module significantly controlled the damages during machining.

This study investigates the mechanical, fatigue, water absorption, and flammability properties of polyethylene terephthalate (PET) core-pineapple fiber sandwich composites reinforced with silane-treated neem fruit husk (NFH) biosilica additives. The novel approach includes modifying the fiber’s surface and incorporating biosilica to enhance environmental resistance. The composites were prepared using a hand layup method, followed by silane treatment of the biosilica, pineapple fiber, PET core and vinyl ester resin. Subsequently, to evaluate environmental impacts on composite’s performance, sandwich composites were subjected to temperature aging at 40^∘C and 60^∘C in a hot oven for 30 days and warm water aging at the same temperatures in tap water with pH 7.4. According to the results, adding 1%, 3%, and 5 vol.% silane-treated biosilica significantly improved the mechanical properties. The composite with 3% biosilica (L2) showed a tensile strength of 120.8MPa, flexural strength of 194.4MPa, compression strength of 182.4MPa, rail shear strength of 20.21MPa, ILSS of 23.14MPa, hardness of 85 Shore-D, and Izod impact strength of 6.56 J. Even under temperature and water aging conditions, the composites showed only minimal reductions in properties, highlighting the efficacy of the silane treatment. The temperature-aged L2 composite had a tensile strength of 104MPa, flexural strength of 172.8 MPa, compression strength of 164MPa, and ILSS of 22.5MPa, while the water-aged L2 composite exhibited a tensile strength of 96MPa, flexural strength of 152.8MPa, compression strength of 146.4MPa, and ILSS of 21.4MPa. Scanning electron microscope (SEM) analysis confirmed uniform dispersion of biosilica particles, critical for improved performance, though higher concentrations led to agglomeration and stress points. The composites also demonstrated excellent flame retardancy, maintaining a UL-94 V-0 rating with decreased flame propagation speeds, specifically 9.05mm/min for L2. These findings underscore the potential of silane-treated biosilica as a reinforcing additive to enhance the durability and performance of composites in adverse conditions.

The Poly(vinylidene) fluoride (PVDF) thin films with a high content of β-phase were prepared by controlling heat-treatment temperature using casting from the poled solvents. The crystallite microstructure of thin films was depicted by the techniques of X-ray diffraction and FTIR. The results showed that heat treatment was favorable for inducing the β- and γ-phase formation of PVDF. The β phase films were obtained with heat treatment at temperatures ranging from 60°C to 120°C and annealing at 120°C after casting from DMF. The thermo-optical effect of β phase PVDF films was investigated using a spectroscopic ellipsometer. At temperatures ranging from 20°C to 100°C, the refractive index of PVDF was negatively correlated with the temperature between 350 and 1500 nm. The value of the t.o. coefficient of PVDF films was calculated at all temperatures. The maximum value of the t.o. coefficient was about 3.3 × 10^-4/°C at the ascending stage of temperature and 3.0 × 10^-4/°C at the descending stage of temperature. Therefore, it is possible to use the thermo-optic effect of the β phase PVDF for long wavelength infrared imaging.

This paper reports on the electron scattering, charge transport and charge trapping of a polymer subjected to intermediate-energy electron beam in a self-consist charging model. Numerical simulation of a charging balance is performed using incident intermediate-energy electron current and leakage current, and the space charging characteristics are examined. The mechanisms involve various microscopic parameters that are related to the space potential and the characteristics of the polymer as well as to the effects of the space charge, electron charge, hole charge and trapped charge itself. The dynamic transporting and trapping properties of a polymer are investigated, and the space potential is evaluated using various parameters of irradiation. Trapping of electrons is determined using Poole–Frenkel trapping–detrapping mechanisms. Various types of space charging behavior are observed by controlling irradiation conditions. Furthermore, the peak location of space charge is simulated and validated by Sessler's experimental data in microscopic perspective.

Carbon nanomaterial (CNM)-reinforced polymer composite is broadly employed in emergent industrial needs due to advanced mechanical properties. In this research paper, a comparatively innovative integrated approach (SOA–CoCoSo) is proposed by using Principal Component Analysis (PCA)-based Combined Compromise Solution (CoCoSo) and Seagull Optimization Algorithm (SOA). This modified module is used in the drilling operation of zero-dimensional (0D) carbon nano-onion (CNO)-reinforced polymer (epoxy) composite. The desired machining performances, namely, surface roughness ($R_a$), thrust force (Th), and Torque (Tr), are optimized to improve the quality and productivity concerns. The control of process constraints, i.e. the wt.% of nanomaterial ($A$), spindle speed ($B$), and feed rate ($C$), was performed to achieve the desired objective value. The drilling experimentation was executed at three different levels of Box–Behnken Design (BBD). The objective function of PCA–CoCoSo was fed as input into the SOA. To acquire a better work efficiency, higher spindle speed, lower feed rate, and incremental wt.% of nanomaterial reinforcement are considered. The results demonstrated that the wt.% of CNO reinforcement and feed rate are the most influential factors for optimal machining performance results. The optimal constraints condition from the SOA–CoCoSo hybrid module is found at a combination of lower level of CNO wt.% (0.5wt.%) and feed rate (61mm/min) and high value of spindle speed (1500rpm). Also, the hybrid SOA–CoCoSo module shows a lesser amount of error percentage than the usual PCA–CoCoSo. The experiments were performed to confirm the feasibility of the suggested hybrid module for optimizing the varying machining parameters. The results indicated that the hybrid method is more efficient than the conventional method.

The carbon nanotubes grafted methylene blue molecularly imprinted polymers (CNT-MB-MIPs) were prepared by grafting aminated carbon nanotubes (CNTs) and copolymerized in the presence of template molecules methylene blue (MB), functional monomers, crosslinkers, and initiators. The results from structural analyses indicate that CNTs were successfully grafted onto the molecularly imprinted polymers (MIPs). The adsorption experiments showed that the adsorption capacity can be affected by grafting CNTs. The adsorption capacity of CNT-MB-MIPs on MB can reach 2793mgg${}^{-1}$ while the initial concentration of MB was 12gL${}^{-1}$, which was higher than that of MB molecularly imprinted polymers (MB-MIPs). Meanwhile, compared with MB-MIPs, CNT-MB-MIPs had a lower adsorption capacity for iron ions, indicating that CNT-MB-MIPs could inhibit the adsorption of iron ions. Adsorption kinetics study showed that the adsorption mechanism of the polymer for MB was in good agreement with the quasi-second-order kinetics model ($R^2=0.9978$) and the adsorption mechanism for iron ions was also in good agreement with the Bangham kinetics model ($R^2=0.9475$). The adsorption isotherm showed that the adsorption process of the two adsorbents was mainly monolayer chemisorption. The remarkable adsorption capacity of CNT-MB-MIPs may be due to the enlargement of adsorption sites on MIPs surface by CNT-NH₂ grafting. At the same time, it can inhibit the adsorption of iron ions, because part of the carboxyl groups in CNT-MB-MIPs are bonded by CNTs, led to few carboxyl groups sites left for adsorbing iron ions, thereby the complex between carboxyl groups and iron ions were inhibited.