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Modifying the wax crystal habit is useful for transporting and processing crude oil at low temperatures. Various polymeric pour point depressant (PPD) additives can aid in this maneuver differently. Various morphologies of polymeric additives (like comb, brush, centipede, etc.,) have been shown to lower the pour point of crude oil by providing several nucleation sites for wax precipitation. Out of the large array of materials available, it is challenging to forecast which one will act as a wax-crystal modifier on the crude oil under consideration. We propose, in this study, a detailed classification of wax-crystal modifier additives based on criteria such as linear or branched copolymers, the presence of crystalline or amorphous segments, aromatic units and their positions (such as in the backbone or branch), the ability to self-assemble or aggregate, etc. Accordingly, we synthesized additives from the maleic anhydride class having three different morphologies namely brush, combs, and centipedes, through free radical polymerization (FRP). The detailed characterization of these additives was carried out using structure-sensitive techniques, such as ¹H nuclear magnetic resonance, Fourier transform infrared spectroscopy, thermogravimetric analysis, and gel permeation chromatography. To evaluate the real-time performance of the as-synthesized additives, we selected crude oils from the South Kadi (SK), Limbodara (LM), and Nada (ND) oil fields of the Cambay basin, Gujarat, India having different levels of wax and asphaltenes. The rheological parameters of crude (with and without additive) were investigated using an Advance Rheometer AR-500. Depending on the additive capability to self-aggregate and the composition of the crude oil, the additive AMI-3 is the most effective for ND, EST-2 for LM, and A-18S for SK crude oils. Their 1000 ppm dose can reduce the pour point of these crudes up to 18 °C and improve their rheological parameters accordingly. Finally, we propose the mechanisms of pour point depression by these as-synthesized additives and carry out the microscopic imaging of the precipitated wax crystals from the blank and additive-treated crude oil.

The fourth period metal fluorides acting as a Lewis acid form binary compounds with nitrogen-containing bases (HCN, NHCH₂, and NH₃), which the calculations are carried out at the MP2 ab initio level with the AVTZ and AVQZ basis set and employed by the CBS method. AIM and IGMH analyses further indicate that the metal-N-bases (M─N) bonding exists in the binary complexes. The strength of interactions is ranging from −4.76 to −56.54 kcal/mol. M─N bonding exhibits a partially covalent nature characterized with a negative energy density and large interaction energy. With the decrease of electronegativity of the substituents on the Lewis base, the interaction energies increase. The M─N interaction is dominated by electrostatic interaction in all complexes, whereas induction and dispersion energies cannot be ignored either.

The photochromic properties of organic bromide salts prepared from 3,6-bis(bromomethyl)durene and nicotinic acid/methyl nicotinate were explored. UV exposure induced color changes, revealing distinct photoresponsive rates for each compound. Structural analysis, electron spin resonance (ESR), and DFT calculations elucidated the underlying mechanisms, highlighting the critical role of electron transfer and supramolecular interactions. This study provides structural insights to enhance the photochromic properties of non-viologen compounds.

The exceptional protective coating can extend the service life of the equipment in a severe marine environment. Carbon fibers (CFs), characterized by high tensile strength, elastic modulus, and excellent chemical resistance, serve as an appropriate filler for coating reinforcement. However, the inadequate fiber/matrix interfacial adhesion makes it difficult to prepare high performance CF-reinforced composites. Therefore, we synthesized a kind of silk fibroin modified CF (CF─SF) as a reinforced-additive for strengthening the corrosion resistance and anti-erosion properties via improving the interfacial adhesion between CFs and resin matrix. The impedance value of composite coating including 1 wt% CF—SF (CF—SF/EP) was 1.65 × 108 Ωˑcm² after immersion, which was two orders of magnitude greater than that of the pure EP coating. In addition, the erosion experiments results showed that the volume loss of EP/CF—SF coating was 132.6 mm³, which decreased by 36.4% and 17.4% compared with EP/CF and EP/CF─O, respectively. The average depth of the CF—SF/EP coating (0.27 mm) was the shallowest among the coatings. Ultimately, we examined the protective mechanism of the CF–SF/EP coating.

This study investigates the development and optimization of activated carbon (AC) from corn silk (CS-AC) and corn silk hydrochar (CS-HC-AC) as a sustainable solution for water purification. For the first time, hydrothermal treatment and activation processes were employed, producing AC from corn silk with improved structural properties. CS-HC-AC exhibited a remarkable S_BET surface area of 331.233 m² g⁻¹, surpassing the 7.335 m² g⁻¹ of CS-AC. Key factors such as temperature, activation time, and activator rate were optimized (100% activator rate, 500 °C temperature, and 60 min activation time), with K₂CO₃ and ZnCl₂ identified as the most effective activators for CS-AC and CS-HC-AC, respectively. The resulting ACs showed high adsorption capacities for heavy metals (Cr(VI), Pb(II), and Ni(II)) and methylene blue dye.

Polyoxometalates (POM) are a class of inorganic metal oxides with distinctive structural characteristics, compositional versatility, high catalytic efficacy, and convenient storage properties. In recent years, POM have shown considerable potential for mimicking enzyme activities. Besides their biological activities, POM have been demonstrated to possess the ability to sense diseases and perform synergistic therapies based on their redox and near-infrared absorption properties. Similar to the metallic nanoparticles and the organic materials, these inorganic clusters also exhibit distinctive photothermal imaging and therapeutic properties. Based on this, the current review focuses exclusively on the application of POM in the photothermal therapy of tumors. Furthermore, the advantages and the potential issues associated with the current POM-based nanomaterials in tumor therapy are discussed and analyzed.

New polymeric spheres of sodium alginate (AlgNa) containing dicarboxylic acids—maleic acid (MA) and oxalic acid (OA)—were developed for adsorption of copper metal from water. Water adsorption capacity, elementary composition, structural, morphological, vibrational, and thermal properties were characterized by scanning electron microscopy (SEM), intumescence degree (IG), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and differential scanning calorimetry. SEM data revealed that functionalization with dicarboxylic acids affects the morphology and surface of the AlgNa matrix. Sample containing MA (0.35 ± 0.004 g) absorbs more water than the OA sphere (0.28 ± 0.007 g). XRD patterns showed that the AlgNa–MA and AlgNa samples exhibit an amorphous nature, whereas the AlgNa–OA sample has a partially crystalline phase. Adsorption experiments were conducted to analyze whether the synthesized spheres could be optimized to reach the best performance in copper adsorption. The adsorbents were most efficient at the highest dosage used (250 mg), corresponding to removal percentages of 84.54 ± 3.97% (AlgNa), 94.21 ± 3.04% (AlgNa–MA), and 84.22 ± 3.39% (AlgNa–OA). The energy-dispersive X-ray spectroscopy maps validated the incorporation of Cu²⁺ ions on the surface of the adsorbents. Kinetic and isotherm assays confirmed the highest efficiency of AlgNa–MA spheres.

This study explores the synergistic antibacterial activity of ZnO nanorods (NRs) decorated with TiO₂ nanoparticles (NPs) and reduced graphene oxide nanosheets (rGO NSs). ZnO NRs and binary ZnO-TiO₂ nanocomposites (ZT NCs) with varying TiO₂ content were synthesized using an in situ sol–gel method and subsequently modified with different amounts of rGO NSs. The nanocomposites were characterized using advanced techniques to assess their structure and antibacterial performance. X-ray diffraction (XRD) confirmed the dominance of the hexagonal wurtzite ZnO structure, while Fourier transform infrared spectroscopy (FT-IR) confirmed interconnectivity. A slight red shift in UV–vis diffuse reflectance spectra indicated changes in optical properties, and BET analysis showed an increase in surface area and pore volume due to rGO incorporation. The ternary ZT-rGO (ZTR) NCs, particularly ZTR 4 (with 4 wt% rGO), exhibited significant antibacterial, antifungal, and antioxidant properties. ZTR 4 showed enhanced efficacy against both Gram-positive (Staphylococcus aureus, Bacillus cereus) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa), as well as Candida albicans. The results highlight the synergistic effects of ZTR NCs, making them promising candidates for applications in biomedical and environmental fields as effective antibacterial agents.

Dye-sensitized solar cells (DSSCs) greatly impacted researchers because of their inexpensive materials (organic/inorganic-based molecules) and relatively simple fabrication process. The fabrication of DSSCs possesses donor-acceptor type light-harvesting materials and simple manufacturing techniques; the technology is the most environmentally friendly. In the process of preparing photoanode, adsorption of dye on the TiO₂ is one of the crucial and time-consuming processes. The conventional method of dye adsorption is carried out by dipping the FTO/TiO₂ electrodes in dye solution for 12 to 48 h. In the DSSCs literature, very few techniques were explored to reduce the dye loading time. This review focuses on various dye loading methods, such as electrical adsorption, spray coating, microwave-assisted ultrasonication, functionalized carboxylate deposition, solution dropping, and electrosorption, and so on. and their consequences in influencing the power conversion efficiency of DSSCs. Dipping and evaporation, solution dropping method, and gas bubbling soaking are inexpensive methods for dye loading. However, the electrochemical methods provide enhanced dye loading within an optimum duration resulting in the improvement of PCE as compared to rest of the methods.

To enhance the utilization value of recycled materials like polyester, nylon, spandex, low-density polyethylene (LDPE), and linear low-density polyethylene (LLDPE), recycled polyester, nylon, and spandex were employed as raw materials. Firstly, the recycled polyester, nylon, and spandex were pretreated in pellet form to obtain pretreated mixed materials. Secondly, these pretreated materials were blended with other materials such as LDPE and LLDPE. Finally, the composite materials were fabricated through extrusion and injection molding. The mechanical properties of LDPE and LLDPE composites modified with recycled polyester, nylon, and spandex were investigated by comparing their respective mechanical properties. The fracture surface microstructure of the composite materials was characterized using scanning electron microscopy. The results are as follows: (a) As the amount of polyester/nylon/spandex-blended chemical fibers increased after pellet pretreatment, the maximum tensile strength, bending strength, and bending modulus of LDPE composites reached 22.16, 32.57, and 1252.8 MPa, respectively. Similarly, for LLDPE composites, the respective maxima were 22.35, 31.03, and 1259.2 MPa. (b) As the content of polyester/nylon/spandex hybrid fibers increased after mass pretreatment, the maximum impact strength and fracture elongation of the LDPE composite were 49.15 kJ/m² and 19.29%, respectively. For LLDPE composite, the respective maxima were 31.64 kJ/m² and 312.1%.