Macromolecular Research最新文献

This study focuses on the design and application of calcium alginate/gum arabic/eggshell powder composite microbeads (CA/GA/ES10) for the removal of methylene blue dye from aqueous solutions through the adsorption method. The characterization of adsorbents was conducted utilizing ATR-FTIR, SEM, XRD, TGA, and pH_pzc. The pH_pzc value of CA/GA/ES10 composite microbeads was determined as 5.56. From optimization studies, the contact time, adsorbent dosage, and pH values were determined as 60 min, 0.1 g/50 mL, and ≅ 7, respectively. The adsorption raw data have been utilized in the non-linear Langmuir, Freundlich, Temkin, and Sips models. The maximum adsorption capacity of CA/GA/ES10 composite microbeads, as per the Sips, was determined to be 33.30 mg/g at 298 K. The high correlation coefficients ((r^{2}) = 0.9976) and low error functions ((chi^{2}) = 0.03) indicate that the non-linear Langmuir is the most appropriate isotherm for the adsorption process. From the Langmuir model, the maximum adsorption capacity was determined as 29.71 mg/g at 298 K. The adsorption process adheres to a non-linear pseudo-second-order ((r^{2}) = 0.9999) and Elovich ((r^{2}) = 0.9999) models. According to thermodynamic results, the adsorption process occurs exothermic ((Delta H^{^circ } = - 3.77;{text{kJ/mol}})) and spontaneous ((Delta G^{^circ } = - 25.83;{text{kJ/mol}};{text{at}};298;{text{K}})) in nature. The impact of varying salt concentrations on the adsorption process was assessed. According to the salt effect, the removal percentage decreased from 81.12 to 65.15% with the addition of NaCl, and from 81.12 to 58.78% with the addition of CaCl₂. The reusability tests show that the composite microbeads created can be used repeatedly for up to 7 cycles. After the 7th cycle, the removal of MB dye decreased from 81.11 to 53.45%. All results showed that the prepared ternary composite microbeads are effective adsorbents for the removal of cationic dye from aqueous solutions.

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Methylcellulose, a cellulose ether derivative with enhanced water solubility and viscosity properties, was modified with three different molecular weights of polyethyleneimine (PEI) (0.8 k, 1.2 k, and 2 k) to synthesize cationic methylcellulose derivatives (MC–PEI). The MC–PEI derivatives exhibited varying conjugation ratios depending on the molecular weight of PEI and demonstrated significantly higher loading efficiencies for the hydrophobic drug, doxorubicin, compared to unmodified MC. The DOX@MC–PEI nanoparticles showed particle sizes ranging from 120 to 160 nm and surface charges between + 26 and + 36 mV. The drug release profiles demonstrated that MC-PEI0.8 k exhibited the highest release rate, followed by MC-PEI1.2 k and MC-PEI2k, respectively. Cytotoxicity evaluations in A549 and MDA-MB-231 cell lines revealed that MC–PEI derivatives possessed higher toxicity than MC but lower toxicity than PEI25k. In addition, the DOX@MC–PEI nanoparticles showed enhanced anticancer effects both in A549 and MDA-MB-231 cells, in particular, DOX@MC-PEI1.2k and DOX@MC-PEI2k nanoparticles showed an increased anticancer effect in MDA-MB-231 cells compared to A549 cells, which might suggest a cell-type specific DOX delivery mechanism of methylcellulose.

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Polyethyleneimine (PEI) modified methylcellulose nanocarriers (MC-PEI) were synthesized using branched PEI with three different molecular weights (0.8 kDa, 1.2 kDa, and 2 kDa). The doxorubicin-loaded nanocarriers demonstrated enhanced anticancer effects against both MDA-MB-231 and A549 cell lines

Today, scientists are working on researching ergonomic, economical materials with protective properties that will make our lives easier. The demand for polymers that exhibit smart properties as well as their cost-effective and lightweight properties is increasing day by day. Giving these materials electrical properties and radiation protection means that many properties can be satisfied with a single material. In this study, ZnO, a semiconductor, was doped at different ratios into a mixture of PLA, a shape memory polymer (smart polymer), and PS, a waste polymer, and its physical properties were investigated in detail. ZnO/polymer blend composite was found to have the bond structures of polymers. It was observed that the crystalline properties of the polymeric composite were determined by ZnO doping, which exhibited a crystal structure. Thermal measurements showed that zinc oxide did not change the phase transformation temperature of the polymeric blend, however, the mass change percentage decreased and the thermal stability increased. The remaining mass was found to be around 30% in the composite containing 40% ZnO. According to the results of optical property measurements, PS-PLA polymers were found to shift from the UV region to the visible region with ZnO and it was also found that the band energy value decreased below 4 eV by adding ZnO and the highest ZnO-containing composite was 3.36 eV. Therefore, it is concluded that the composites exhibit semiconducting properties. The spectroscopy results showed that for 661 keV, the linear absorption capacity in the polymeric composite increased from 0.65 cm⁻¹ to 2.29 cm⁻¹ with increasing ZnO percentage, which can be interpreted as an increase in shielding capability.

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Production of ZnO doped polymerblend

In recent years, gradient hydrogels have aroused great interest because of their heterogeneous structure and irregular shape changes. The gradient hydrogels have been widely used in tissue engineering and biomedical fields, because they can respond to stimuli to achieve functions. In general, gradient hydrogels are prepared by applying an external field. The applicable conditions of various external fields are different, and the appropriate preparation method should be selected according to the needs. In this mini-review, we classified and discussed the external fields that induce gradient structure of hydrogel, such as gravitational field, temperature field, light field, electric field, magnetic field, and acoustic field. We hope that this article can provide new insights for the design of gradient hydrogels.

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We classified and discussed the external fields that induce gradient structure of hydrogel, such as gravitational field, temperature field, light field, electric field, magnetic field and acoustic field. We also look at their challenges and development prospects

A novel approach, termed electrochemical weaving, is presented for the substrate-free and scalable synthesis of conducting polypyrrole (PPy) sheets. The PPy sheet grows in less than 1 h at the surface of the solution containing NO₃⁻ and Py, while remaining attached to the anode on one side under a constant anodic voltage. The shape and dimensions of the PPy sheet can be adjusted by modifying the shape and dimensions of the electrodes. The presence of NO₃⁻ is confirmed to be essential in any form, as it produces the oxidizing species NO⁺, which initiates the surface polymerization of PPy. The prepared PPy sheet has two distinct sides: the liquid-side, which exhibits a spherical morphology, and the air-side, which features a microchannel structure. The air-side surface has a grooved texture visible to the naked eye and this grooved structure appears to grow toward the counter electrode. The resulting sheet is flexible, easily manipulated, and can be held by hand. This study introduces a simple method for fabricating of high-surface-area PPy films with microchannel structures using an electrochemical 2D printing technique. This emerging method has potential application in various research fields requiring scalable conducting polymer sheets.

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Electrochemical weaving machine for scalable growth of conducting polymer sheet

Numerous industries generate substantial quantities of waste cotton fibers as byproducts; however, their potential applications are restricted by their inherent fire hazard. In sectors such as construction, residual cotton fibers can be employed as insulation materials and other building components, and their efficacy can be improved by enhancing their flame retardancy. Recycling waste cotton fibers is a cost-effective solution that promotes recycling and conserves resources. This study investigates the efficacy of four phosphorus-based flame retardants for enhancing the flame retardancy of waste cotton fibers: ammonium phosphate monobasic (AP-1), ammonium phosphate dibasic (AP-2), ammonium polyphosphate (APP), and tris(2-chloropropyl) phosphate. Calorimetry, which objectively assesses flame retardancy performance by measuring the heat release rate during combustion, is used as the primary analytical method. Further, cone and bomb calorimeters are employed to acquire more comprehensive and stable calorimetry data. The calorimetry analysis results indicate that AP-1 exhibited a superior flame-retardant performance. AP-2 and APP formed significant char residues, exhibiting superior adhesion to cotton fibers and effective action on combustion gases, as confirmed via thermogravimetric analysis and scanning electron microscopy with energy-dispersive X-ray spectrometry. Char formation is another important mechanism; however, the overall effectiveness of flame retardants is significantly affected by their interaction with fiber materials and their behavior during combustion. AP-1 is the most effective flame retardant for waste cotton fibers and displays thermal stability and flame suppression effects. This study demonstrates the flame-retardant effect through precise calorimetry analysis data and suggests the possibility of recycling waste cotton fibers into high-value-added products.

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The essential indicator of how quickly a material releases heat (HRR) showed significantly lower values for the AP-1-treated fibers compared to those of other samples. This reduction indicates that the flame-retardant treatment effectively slows the combustion rate and contributes to better flame retardancy. THR indicates the total amount of energy released during combustion, further supporting the research findings.

Natural biodegradable polymers have been extensively studied as scaffolds for three-dimensional (3D) cancer cell culture in high-throughput screening (HTS) for anticancer drug discovery. This study fabricated a chitosan-based scaffold combined with pectin at different ratios: 10:90, 40:60, 60:40, and 90:10. Collagen I, the most abundant component of breast cancer extracellular matrix (ECM), was added to the scaffold formula. The composite scaffold displayed an interconnected, open-pore structure with tunable porosity, swelling, and degradable characteristics at different chitosan-to-pectin ratios. A high ratio of chitosan to pectin (60:40 and 90:10) exhibited the ideal properties for a 3D scaffold suitable for cell culture. These scaffolds supported the attachment and growth of the T47D breast cancer cell line. Additionally, this 3D cell culture demonstrated doxorubicin and tamoxifen resistance when compared to 2D culture. Therefore, it is a feasible and promising tool for more reliable anticancer drug screening.

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Biomimetic scaffold supports 3D growth of breast cancer cells. This system mimics breast cancer tissue which grows on ECM networks, offering a personalized and better model for anticancer drug screening.

With the expansion of the virtual reality (VR) and augmented reality (AR) market, the close transmission of movement through human–machine interaction has become increasingly important. Polyurethane, a fiber used in various clothing and suits, possesses suitable elasticity and tensile strength. This makes it a material that can be closely attached to the skin without causing discomfort. However, since polyurethane is not a conductor, there is a disadvantage that it is impossible to detect electrical signals. Here, we synthesized polyurethane sulfonate (PUS) which is a hydrophilic modified polyurethane containing a high amount of sulfonate groups. This modified polyurethane shows the improved affinity with poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) by intermolecular interaction of sulfonate group and PSS. Finally, an elastic strain sensor was fabricated with PEDOT:PSS coated on PUS over a large area of 100 cm². This strain sensor induces resistance changes according to the elastic expansion of the PUS. The fabricated strain sensor was applied to finger joints and biceps, successfully detected movements corresponding to bending and expansion.

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An elastic nanocomposite consisting of poly(butylene succinate-co-ethylene terephthalate) and nano-hydroxyapatite was produced through the electrospinning technique, and the influence of hydroxyapatite nanoparticles in the nanofiber, along with the presence of citric acid in simulated body fluid, was examined with respect to the wet chemical nucleation of hydroxyapatite. The structure of the nanoparticles, as well as their dispersion on the nanofiber surface, was investigated using EDS and SEM, respectively. The inclusion of nanoparticles in the nanofiber structure leads to the formation of hydroxyapatite nanoparticles that coat the entire surface of the scaffold, with some regions showing particle clustering. The introduction of citric acid promotes particle dispersion, eliminating particle clustering and achieving a highly consistent distribution across the fibers. In the optimal case, a nanocomposite with a composition of 63.4% nanoparticles and 36.6% elastic polymer fibers is produced. The biocompatibility of the scaffolds was assessed using MTT assays, immunofluorescent cell staining, and the interaction between the scaffolds and cells in an osteogenic environment was examined through Alizarin Red staining.

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Fabrication of bone ECM-like scaffolds with a high percentage of nanohydroxyapatite using the wet chemical method.

Epoxy-based materials, known for their exceptional durability, are extensively used across various fields. However, a significant drawback of epoxy resins is that their curing agents, typically derived from petroleum, can pose environment risks. This study aims to develop new systems as alternatives to petroleum-derived curing agents. The incorporation of environmentally friendly curing agents in epoxy resins has the potential to significantly reduce the carbon footprint and decrease health risks to living organisms. For this purpose, the amine modified three-dimensional zeolite imidazolate framework (ZIF) was first prepared. Subsequently curing studies were carried out using epoxy resins composed of a petroleum-derived resin, a plant-based resin, and their mixtures. The resulting ZIF and amine-functionalized ZIF were characterized using FTIR and XRD techniques. Epoxy films were then prepared with three different curing agents across three distinct epoxy resin systems. Mechanical, thermal, and chemical analyses of the films were performed. Additionally, coatings were applied to glass surfaces, and their surface properties were evaluated. In reactions involving ZIF for epoxidized resorcinol, it was observed that the curing temperature shifted slightly to a higher range from 95 to 131 °C. The thermal degradation temperatures of the films containing ZIF also increased, resulting in more thermally stable materials. The maximum weight loss temperatures increased by 168 °C for RDGE and by 88 °C for the mixture of RDGE and ESO. Improved thermal stability can lead to a longer service life and greater performance in extreme conditions.

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Explores sustainable alternatives to petroleum-based curing agents in epoxy resins. ZIF with amine groups as eco-friendly curing agents was synthesized and functionalized. Thermal stability in epoxy films using ZIF-based curing agents was enhanced. Mechanical, thermal, and surface properties of ZIF-incorporated epoxy coatings were evaluated