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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.

UV embossing for polymeric micro-patterning thin film is an emerging replication technique. This paper investigates UV curable multifunctional acrylates pre-polymer resin patterned by a micro-structured mold and subsequently cured by UV irradiation. To further enhance this duplication method for high aspect ratio production, demolding must be reliable and repeatable without damage to the embossing or mold. Previously, it has been reported that UV embossed patterns for aspect ratios as high as 14 have been achieved experimentally. Finite element analyses for patterns with aspect ratios of 5 using parallel demolding between two parallel plates have also been reported. However, the parallel demolding method may not be suitable for large area patterns as forces generated were high. As such, an alternative demolding method, namely peel demolding, for micro-patterns with an aspect ratio of 14 was investigated and key parameters identified. The parameters governing the demolding process were the peel angle, the pre-crack condition, shrinkage, interface fracture toughness, tensile strength and modulus of polymer. A pre-crack between the polymer and mold was introduced before peel demolding. Numerical analyses in terms of Cohesive Zone Modeling (CZM) were used to simulate the demolding process. Shrinkage caused by UV exposure was represented by thermal strain effects and the fully cured polymer was peeled off using displacement control. The ultimate tensile strength (U.T.S) of the cured polymer was used as a failure criterion. The stresses involved were crucial for determining clean demolding. As peeling progressed, stresses experienced in the polymer matrix increased rapidly in the region ahead of the crack with little or no stress at the cracked region. When stresses experienced by the polymer were below the U.T.S, demolding was deemed to be successful.

Electrospinning is a very simple and versatile process by which polymer nanofibers with diameters ranging from a few nanometers to several micrometers can be produced using an electrostatically driven jet of polymer solution (or polymer melt). Significant progress has been made in this process throughout the last decade and the resultant nanostructures have been exploited to a wide range of applications. An important feature of the electrospinning process is that electrospinning nanofibers are produced in atmospheric air and at room temperature. This paper reviews the assembled polyacrylonitrile (PAN)-based carbon nanofibers with various processing parameters such as electrical potential, distance between capillary and collector drum, solution flow rate (dope extrusion rate), and concentration of polymer solution. The average fiber diameter would increase with increasing concentration of the polymer solution and the flow rate. Therefore, the screen distance could also increase but the average electrical potential of the fibers diameter decreases. Electrospinning process can be conducted at higher electrical potentials, lower flow rate, nearer screen distance, and higher concentrations of dope.

One of the most important techniques to improve the functional properties of organized molecular films is to introduce nanometer-size solid particles into them. The Langmuir balance has proved to be useful for controlling and modifying these films by organizing molecules into highly ordered structures. Our aim is to study the efficacy of this technique to improve the compactness of biocompatible polymer films by incorporating nanosilica particles. The experimental technique consists of first adsorbing the polymer on silica particles in an aqueous medium, followed by preparation of a monolayer at the air–water interface in a Langmuir balance. The film is organized by repeated expansion and compression. The surface pressure-surface area characteristics are recorded during each cycle. The pressure of the film increases with decrease in the mean molecular area, but reaches a plateau, probably due to instability of the film. With repeated cycling, the plateau pressure increases indicating that the film has become more stable and rigid. The cycling is continued till plateau pressure does not change with further cycling. The amount of the polymer loaded on the subphase and the ratio of PEO to silica in the film, on the plateau pressure has been studied. A substantial increase in the stability and rigidity of the film is achieved by this technique.

In this project, nanocomposite films were prepared with different Titanium dioxide (TiO₂) percentages. Properties of polycarbonate (PC) and PC–TiO₂ nanocomposite films were studied by X-ray diffraction (XRD) analysis and Fourier transform infrared (FTIR) spectroscopy. The structure of samples was studied by XRD. The mechanical properties of PC–TiO₂ nanocomposite films were investigated by conducting tensile tests and hardness measurements. Thermal stability of the nanocomposites was studied by thermogravimetric analysis (TGA) method. The elastic modulus of the composite increased with increasing weight fraction of nanoparticles. The microhardness value increases with increasing TiO₂ nanoparticles. The results of tensile testing were in agreement with those of micro-hardness measurements. In addition, TGA curves showed that nanocomposite films have higher resistance to thermal degradation compared to polycarbonate. There are many reports related to the modification of polycarbonate films, but still a systematic study of them is required.

This research aims to study the addition of nanoclays on unsaturated polyester (UP) and epoxy resin (EP) as filling and by weight percentage (2%, 4% and 6%) to this mixture and then study the extent of the effect of this addition on wear rate of the composites’ material where three loads were adopted (10, 15 and 20N), respectively, on the iron hard disk (269 HB) and copper hard disk of 111HB for the resin before and after adding the clays, where the approved sliding velocities were 4.1887, 3.1415 and 2.0943m/sec, respectively, and the test duration was 10 min on the test disc. Immersion of samples in the water for 2, 4, 6 and 8 weeks showed a clear improvement in the wear rate and tear values of dry and submerged conditions in a water under different conditions of load change, slipping speed, time and temperature stability after adding the nanoclays to the polymer.

In recent times, nanomaterials have attracted the interest of the scientific community with their superior applications when compared to bulk counterparts. Tungsten oxide (WO₃) nanoparticles (NPs) with their distinct properties such as electrochemical, photocatalytic, photoluminescent and gas sensing capabilities, are highly sought out. With these distinct properties, WO₃ NPs find significant application in device fabrication. This review provides an overview of the different synthesis methods, the properties and applications of tungsten oxide and doped tungsten oxide. The enhanced properties of WO₃ NPs with doping are also discussed in detail. In addition, this review also emphasizes on properties of WO₃ polymer nanocomposite and their applications in several areas of human enterprise.

Polymer nanocomposites (PNCs) are functional hybrids lying at the interface of organic and inorganic realm, whose high versatility offers numerous possibilities to develop tailor-made materials with advanced material behaviors. Accordingly, a considerate combination of optically effective additive and particle-stabilizing polymer often opens up unique design possibilities, thereby offering momentous lead in creating advanced functional materials for targeted techno-commercial applications. Accordingly, optically effective nanofillers characterized by particle size and dielectric constant of the surrounding medium-dependent surface plasmon resonance effects may induce entirely new optical functionalities (UV and visible light absorption, optical dichroism, spectral manipulation, photonic emission and so forth) in the polymeric host. Herein, we discuss the major causative factors, which enable nanostructured materials to exhibit unique properties, general introduction to nanotechnology-enabled polymer-based nanocomposites and present a comprehensive review on functional properties and related applications of PNCs, with special emphasis on optical functionalities (photonic absorption encompassing UV shielding, color switching and refractive index engineering and photonic emission covering photoluminescence and spectral manipulations). This review also sheds light on the effect of nature of filler, filler morphology, filler size and filler composition and dispersion homogeneity on optical behaviors of polymer nanocomposites.

In this paper, photoexcitation processes in the bilayer devices based on inorganic materials and poly(N-vinyl-carbazole) (PVK) were investigated. In order to clarify the roles of inorganic materials in photoconductive properties of bilayer devices, TiO₂ and ZnS were chosen to combine with PVK. A model for generation of photocurrent (I_ph) in single layer device of PVK was obtained. It is deduced that the recombination rate constant (P_comb) and the ionization rate constant (γ) of excitons should be considered as the most important factors for (I_ph). For inorganic materials (TiO₂ or ZnS)/PVK bilayer devices, in reverse bias of -4 V, the photocurrent of 115 mA/cm² in the TiO₂/PVK device was observed, but the photocurrent in the ZnS/PVK device was only 10 mA/cm² under the illumination light of 340 nm and the light intensity of 14.2 mW/cm². The weaker photocurrent is attributed to the absorption of ZnS within UV region and the energy offset at the interface between PVK and ZnS, which impedes the transport of charge carriers.

In this study, two polymeric resins with different pore sizes were synthesized to study comparative adsorption of reactive black KNB dye. Styrene-divinylbenzene copolymer resin NG-8 has an average pore size of 3.82 nm, about half of that of polydivinylbenzene resin NG-7 (6.90 nm). NG-8 also has a surface acidity about 4 times that of NG-7, resulting in a much more negative surface of the former resin as compared to the latter at pH 6.05. Equilibrium adsorption of KNB was significantly influenced by the surface functionality of the resins, as evidenced by the observations that NG-8 adsorbed constantly less KNB than NG-7 and that the presence of CaCl₂ enhanced the adsorption by both resins. The intra-particle diffusion appears to be the primary rate-limiting process. While the pores of both resins are accessible to KNB, the slower adsorption by NG-8 than by NG-7 suggests that the smaller pores of NG-8 further retard the intra-particle diffusion of KNB.

A partition function and a complete thermodynamic description for pure polymer fluids have been investigated based on a self-avoid-walk lattice model. Caused by the introduction of Gibbs distribution into the Flory-Huggins theory, the partition function and the thermodynamic description depicted their dependence on temperature well. In the present study, we applied the theory to calculate polymer solubility parameters. The polymer solubility parameters predicted by our theory are well consistent with the experiment values.

The carrier transport properties of the blends of the hole transport material poly(N-vinylcarbazole) (PVK) and the electron transport material tris (8-hydroxyquinolinolato) aluminum III (Alq₃) are investigated at room temperature using steady-state and time-resolved transient photocurrent measurements as a function of doping concentration of Alq3. Due to lower LUMO and higher HOMO energy level of Alq₃ than those of PVK, Alq₃ molecules may act as carrier trap states in PVK films at low concentration. However, at high concentration of Alq₃, phase separation reduces trap states to some extent, which leads to the rise of photocurrent. It is concluded that strong excitation transfer from PVK to Alq₃ does harm to photocurrent, because strong fluorescence effect of Alq₃ inhibits photogeneration of charge carriers. In time-resolved transient photocurrent measurements, it is found that the decay time is obviously shortened because the recombination rate increases and the electron mobility of Alq₃ is higher than the hole mobility of PVK.

A series of spherical activated carbons (SACs) with different pore structures were prepared from chloromethylated polydivinylbenzene by ZnCl₂ activation. The effects of activation temperature and retention time on the yield and textural properties of the resulting SACs were studied. All the SACs are generated with high yield of above 65% and exhibit relatively high mesopore fraction (me%) of 35.7%–43.6% compared with conventional activated carbons. The sample zlc28 prepared at 800°C for 2 h has the largest BET surface area of 891 m² g^-1 and pore volume of 0.489 cm³ g^-1. SEM and XRD analyses of zlc28 verify the presence of developed porous structure composed of disordered micrographite stacking with large amounts of interspaces in the order of nanometers.

Cadmium sulphide (CdS) nanocrystallites were prepared by sulphuration route with capping in polyethylene oxide (PEO) polymer matrix. It is found that PEO could provide a confined environment for particle nucleation and growth of CdS nanocrystallites. The scanning electron microscopy (SEM) with energy dispersive analysis by X-ray (EDAX) studies confirms the presence of CdS nanocrystallites in polymer matrix. X-ray diffraction (XRD) studies and transmission electron microscopy (TEM) selected area diffraction (SAD) patterns show that these crystallites have hexagonal structure. The TEM and UV-Visible absorption studies indicate uniform size distribution having size around 2.3 nm and band gap of 2.7 eV. X-ray photoelectron spectroscopy (XPS) studies reveal that core level energy positions of the Cd is shifted towards the lower binding energy and has similar chemical environment to that of bulk CdS.

A novel and shape-controlled synthesis method for uniformly-shaped poly(p-phenylenediamine) (PpPD) microparticles was developed using (NH₄)₂S₂O₈ (APS) as an oxidant. The results demonstrated that the morphologies of PpPD varied from nanofibers to nanospheres and nest-like microspheres by tuning the pH of solution. Tiny pH change leads to the significant change in product morphology. The structure of microspheres is similar to graphene which was first discovered. Further study showed that the PpPD nanofibers were dimer. The difference in the structure of PpPD nanofibers and nanospheres (microspheres) resulted in different solubility in water. The nanosized oligomer crystallites served as starting templates for the nucleation of PpPD nanofibers. Further growth of nanofibers was proceeded by the self-organization of phenazine units or their blocks located at the ends of the PpPD chains.

The electrochemical properties of poly sodium 4-styrenesulfonate intercalated graphite oxide (PSSGO) have been investigated in a 1 M H₂SO₄ electrolyte. We observed capacitor behavior at scan rate of 1–25 mV/s in a cyclic voltammetry. Specific capacitance obtained from galvanostatic charge and discharge measurements were 6 F/g to 102 F/g at 1 A/g to 0.1 A/g, respectively. The specific capacitance of PSSGO is relatively high compared to that of the precursor graphite oxide in which the specific capacitance was 11–20 F/g at 0.03 A/g. Capacitance retention was 73% after 3000 cycles, proving reliable cyclic stability up to 3000 cycles.