Kombucha bacterial cellulose (KBC), a byproduct generated during kombucha fermentation, can be considered an appropriate biomaterial for use in the process of microbial immobilization. This study examined the properties of KBC, developed through green tea kombucha fermentation on days 7, 14, and 30, and its potential to serve as a protective delivery system for the beneficial microorganism Lactobacillus plantarum. The maximum KBC yield, 65%, was recorded on the 30th day. Scanning electron microscopy provided a way to study the development and changes in the KBC's fibrous architecture over time. X-ray diffraction analysis demonstrated a type I cellulose classification for the samples, with crystallinity indices of 90-95%, and crystallite sizes between 536 and 598 nanometers. The Brunauer-Emmett-Teller method was used to determine the 30-day KBC's surface area, a maximum of 1991 m2/g. The adsorption-incubation method was employed to immobilize L. plantarum TISTR 541 cells, resulting in a cell density of 1620 log CFU/g. Freeze-drying of immobilized Lactobacillus plantarum resulted in a viable cell count of 798 log CFU/g, which was diminished to 294 log CFU/g after simulated gastrointestinal exposure (HCl pH 20 and 0.3% bile salt); conversely, no free Lactobacillus plantarum cells were detected. Its potential as a protective conduit for delivering beneficial bacteria to the digestive system was indicated.
The special properties of synthetic polymers, including biodegradability, biocompatibility, hydrophilicity, and non-toxicity, are key factors in their applications in modern medical settings. Monocrotaline in vivo Essential for contemporary wound dressing fabrication are materials designed for controlled drug release. A key intention of this study was the development and detailed analysis of polyvinyl alcohol/polycaprolactone (PVA/PCL) fibers loaded with a prototype drug. A mixture of PVA and PCL, incorporating the medicinal substance, was extruded into a coagulation bath, causing it to solidify. The developed PVA/PCL fibers were given a rinse and then thoroughly dried. In pursuit of enhanced wound healing, the fibers were characterized using Fourier transform infrared spectroscopy, linear density measurements, topographic examination, tensile properties testing, liquid absorption capacity, swelling behavior, degradation studies, antimicrobial activity, and drug release profiles. The experimental results led to the conclusion that wet-spun PVA/PCL fibers containing a model drug showcased robust tensile properties, acceptable liquid absorption, swelling percentages, and degradation rates, and significant antimicrobial activity, with a controlled release profile of the model drug, aligning with their intended application in wound dressings.
Organic solar cells (OSCs) of superior power conversion efficiency have been largely produced using halogenated solvents. Unfortunately, these solvents have significant toxic effects on human health and the environment. Recently, non-halogenated solvents have arisen as a promising alternative. Nevertheless, the achievement of an ideal morphology has been constrained when utilizing non-halogenated solvents, such as o-xylene (XY). A detailed examination of the photovoltaic properties of all-polymer solar cells (APSCs) and their connection to various high-boiling-point, non-halogenated additives was performed. Monocrotaline in vivo XY was employed to dissolve PTB7-Th and PNDI2HD-T polymers that were synthesized. Following this, PTB7-ThPNDI2HD-T-based APSCs were created using XY, containing five additives: 12,4-trimethylbenzene (TMB), indane (IN), tetralin (TN), diphenyl ether (DPE), and dibenzyl ether (DBE). The photovoltaic performance was determined in the following order: XY + IN, less than XY + TMB, less than XY + DBE, XY only, less than XY + DPE, less than XY + TN. The photovoltaic properties of APSCs processed with an XY solvent system were demonstrably better than those of APSCs processed with a chloroform solution containing 18-diiodooctane (CF + DIO). Transient photovoltage and two-dimensional grazing incidence X-ray diffraction experiments were instrumental in uncovering the key reasons behind these discrepancies. Among APSCs, those incorporating XY + TN and XY + DPE configurations had the longest charge lifetimes. This extended lifetime was a result of the nanoscale morphology in the polymer blend films, characterized by the smooth surfaces and the untangled, evenly distributed, and interconnected network of PTB7-Th polymer domains. An optimal boiling point additive proves crucial in crafting polymer blends with advantageous morphologies, as evidenced by our findings, potentially fostering wider adoption of eco-friendly APSCs.
A hydrothermal carbonization method, in a single step, was used to create nitrogen/phosphorus-doped carbon dots from the water-soluble polymer, poly 2-(methacryloyloxy)ethyl phosphorylcholine (PMPC). PMPC synthesis involved the free-radical polymerization of 2-(methacryloyloxy)ethyl phosphorylcholine (MPC) in the presence of 4,4'-azobis(4-cyanovaleric acid). PMPC water-soluble polymers, bearing nitrogen and phosphorus functionalities, are instrumental in the synthesis of carbon dots (P-CDs). To determine the structural and optical characteristics of the produced P-CDs, advanced techniques including field emission-scanning electron microscopy (FESEM) with energy-dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Raman spectroscopy, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), ultraviolet-visible (UV-vis) spectroscopy, and fluorescence spectroscopy, were employed. Synthesized P-CDs exhibited stable, bright/durable fluorescence lasting for extended durations, substantiating the incorporation of oxygen, phosphorus, and nitrogen heteroatoms into the carbon framework. The synthesized P-CDs, exhibiting vibrant fluorescence, exceptional photostability, and emission varying with excitation, along with an impressive quantum yield of 23%, are being explored for use as a fluorescent (security) ink for drawing and writing (anti-counterfeiting applications). In addition, the results of cytotoxicity studies, which were vital for determining biocompatibility, were used to guide the subsequent cellular multi-color imaging within nematodes. Monocrotaline in vivo Utilizing polymers to prepare CDs, this study not only demonstrated their potential as advanced fluorescence inks, bioimaging agents for anti-counterfeiting, and candidates for cellular multi-color imaging, but also highlighted a novel and streamlined approach to producing bulk quantities of CDs for diverse applications.
This research focused on the creation of porous polymer structures (IPN) from the combination of natural isoprene rubber (NR) and poly(methyl methacrylate) (PMMA). An analysis was performed to ascertain how the molecular weight and crosslink density of polyisoprene affect its morphology and miscibility with PMMA. The creation of sequential semi-IPNs was completed. The interplay of viscoelastic, thermal, and mechanical properties in semi-IPNs was explored through systematic analysis. A key factor in influencing miscibility within the semi-IPN, according to the results, was the crosslinking density of the natural rubber. A direct correlation was observed between a doubling of the crosslinking level and a greater degree of compatibility. Simulations of electron spin resonance spectra were used to compare the degree of miscibility at two different compositions. When the percentage by weight of PMMA was below 40%, the compatibility of semi-IPNs was found to be more effective. A morphology of nanometer dimensions was achieved when the NR/PMMA ratio was 50/50. A certain level of phase mixing and an interlocked structure influenced the storage modulus of the highly crosslinked elastic semi-IPN, replicating the pattern observed in PMMA following its glass transition. The porous polymer network's morphology was found to be readily tunable through a suitable selection of crosslinking agent concentration and composition. A dual-phase morphology was observed due to the combination of a high concentration and a low crosslinking level. Porous structure development was facilitated by the application of the elastic semi-IPN. There was a connection between the mechanical performance and morphology, and the thermal stability was equivalent to pure NR's. Potential carriers of bioactive molecules, identified through investigation, could find innovative applications in food packaging, as well as in other sectors.
In this work, neodymium oxide (Nd³⁺) was incorporated into PVA/PVP blend polymer films using a solution casting method, with varying concentrations explored. Employing X-ray diffraction (XRD) analysis, the composite structure of the pure PVA/PVP polymeric sample was investigated, demonstrating its semi-crystalline characteristics. Through the Fourier transform infrared (FT-IR) analysis, a tool for chemical structure determination, a substantial interaction was revealed between PB-Nd+3 elements in the polymer blends. In the host PVA/PVP blend matrix, transmittance data indicated 88%, while absorption for PB-Nd+3 rose proportionally to the elevated dopant quantities. Optical estimations of direct and indirect energy bandgaps, achieved through the application of absorption spectrum fitting (ASF) and Tauc's models, indicated a drop in bandgap values as the concentration of PB-Nd+3 was increased. The investigated composite films demonstrated a substantially greater Urbach energy value as the PB-Nd+3 content was elevated. Moreover, within this current research, seven theoretical equations were used to illustrate the interplay between the refractive index and the energy bandgap. Analysis of the proposed composites revealed indirect bandgaps within the range of 56 eV to 482 eV. In parallel, the direct energy gaps decreased from 609 eV to 583 eV as the proportions of dopants increased. PB-Nd+3 inclusion demonstrably affected the nonlinear optical parameters, causing an upward trend in their values. Composite films of PB-Nd+3 exhibited enhanced optical limiting capabilities, resulting in a laser cutoff in the visible light spectrum. For the blend polymer embedded in PB-Nd+3, the low-frequency portion of the dielectric permittivity's real and imaginary components exhibited an increase.