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Shea Irwin posted an update 6 months ago
While carbon sources suitable for the application and surface modifications are essential, finding them continues to pose a challenge. The synthesis of CQDs with different surface groups using PEO106PPO70PEO106 (Pluronic F127) as the carbon source was achieved through a hydrothermal method and subsequent surface modifications involving ammonia and thionyl chloride. The particle size of the CQDs prepared using the initial method was found to be distributed from 23 to 35 nanometers on average. Unmodified CQDs displayed the peak relative photoluminescence intensity; however, all as-prepared CQDs exhibited anomalous photoluminescence, situated beyond the boundaries of the visible spectrum. Amidst the various modifications, CQDs treated with ammonia showed a degradation rate of 99.13% for a 50 mg/L indigo carmine solution within 15 days, which was more effective than thionyl chloride-modified CQDs, achieving a degradation rate of 97.59% in a light green SF yellowish solution over the same period. Using as-prepared carbon quantum dots, with tailored surface modifications, this study effectively demonstrates the photocatalytic degradation of two common types of organic dyes.
Amino cellulose (AC), despite its biodegradable, biocompatible properties, and superb film-forming potential, exhibits poor mechanical properties and insufficient thermal stability in film form. This study reports on a novel composite film comprising AC and curcumin-stearylamine-based benzoxazine (C-st), designed to improve its functionality and promote its application. Through the utilization of C-st and AC as starting materials, a C-st/AC composite film was produced, its synergistic attributes being attributable to chemical cross-linking and hydrogen bonding. Two significant aspects of the curing process were determined. Synthesizing the benzoxazine monomer from fully bio-based precursors, specifically curcumin and stearylamine, resulted in a curing onset temperature of 163°C. The mixing of C-st and AC engendered a synergistic impact on the rectification of behavioral patterns. Following tensile testing and thermal analysis, poly(C-st) significantly enhanced the composite films’ mechanical and thermal properties, exhibiting superior performance even under elevated temperatures. The composite films displayed a twenty-five-fold improvement in tensile strength relative to the AC film, suggesting their viability for specialized functional uses. The substitution of naturally occurring polymer films in film-related applications with poly(C-st)/AC films is enabled by the latter’s improved mechanical and thermal properties.
Three linear triblock terpolymers, two of the ABC type and one of the BAC type, are reported. These terpolymers incorporate three chemically dissimilar blocks: polystyrene (PS), poly(butadiene) with a nearly exclusive vinyl-type -12 microstructure (PB12), and poly(dimethylsiloxane) (PDMS). Living anionic polymerization facilitated the creation of terpolymers with a narrow dispersion of components, exhibiting comparatively low average molecular weights and variable composition ratios, as confirmed through multiple analytical techniques. Transmission electron microscopy and small-angle X-ray scattering studies were performed to assess their self-assembly behavior, illustrating how asymmetric compositions, intermolecular interactions, and inverted segment order affect the adopted morphologies. Moreover, post-polymerization chemical alterations, including hydroboration and oxidation, were performed on the extremely low molecular weight PB12 constituent in each of the three terpolymer specimens. The successful integration of -OH groups into the polydiene segments and the synthesis of polymeric brushes were verified through a series of molecular, thermal, and surface analysis studies. highthroughput signalsscreenings To the best of our knowledge, this represents the first exploration of synthesis and chemical modification techniques on triblock terpolymers. It signifies a promising strategy for polymer development in nanotechnology applications.
A key factor in the economics and environmental impact of material extrusion additive manufacturing is its energy efficiency. The 3D printing of functional products requiring premium quality and substantial mechanical strength necessitate a well-established system of control parameters, dictated by market demand. Meeting numerous objectives poses a considerable challenge, particularly with regard to industrial polymers possessing multiple functionalities, like polymethyl methacrylate. This paper focuses on evaluating how six critical control factors—infill density, raster deposition angle, nozzle temperature, print speed, layer thickness, and bed temperature—impact the energy efficiency of Poly, in contrast to its mechanical performance. The experiment, structured using a five-level L25 Taguchi orthogonal array with five replications, constituted 135 trials. To document the 3D printing time and the electrical consumption, a stopwatch was utilized. Experimental results provided the values for tensile strength, modulus, and toughness. The raster deposition angle and the printing speed showed the most pronounced effects on tensile strength, taking the top two positions in terms of control parameter impact. Energy consumption was directly proportional to the chosen layer thickness and printing speed parameters. Quadratic regression model equations for each response metric over the six control parameters were compiled and subsequently validated. Accordingly, the ideal trade-off between energy efficiency and mechanical strength is realized, and a tool yields substantial value in engineering projects.
This research endeavors to investigate the efficacy of molecular imprinting for crafting highly selective macromolecular sorbents that facilitate the selective sorption and subsequent separation of light and heavy rare-earth metals, including samarium and gadolinium. Owing to the formation of complementary cavities during molecularly imprinted polymer synthesis, these sorbents appear promising, as they selectively bind only the targeted rare-earth metal. Specifically, the proposed macromolecules offer an advantage by not absorbing similar metals simultaneously through sorption. Two molecularly imprinted polymer (MIP) types were prepared using methacrylic acid (MAA) and 4-vinylpyridine (4VP) as functional monomers. An examination of the sorption properties (extraction degree, exchange capacity) of the MIPs was conducted. A study investigated the effect of template removal cycle counts (ranging from 20 to 35) on sorption effectiveness. Experiments in the laboratory focused on the selective sorption and separation of samarium and gadolinium from a simulated solution.
HFRP composites, recently developed, are designed to boost the strength and ductility of normal and lightweight aggregate concrete, along with concrete using recycled brick aggregate. Besides this, experimental and analytical approaches have been employed to ascertain the suitability of the existing strength and strain models. Nevertheless, the theoretical and analytical formulations for anticipating the stress-strain characteristics of HFRP-reinforced concrete remained underdeveloped. Accordingly, the central focus of this study was the development of analytical equations to predict the stress-strain curves for HFRP-reinforced waste brick aggregate concrete specimens. To explore the potential of HFRP to augment the mechanical properties of concrete incorporating recycled brick aggregates, a novel experimental approach was performed. The categorization of concrete, determined by its strength, resulted in two types: Type-1 concrete and Type-2 concrete. A trial was undertaken with sixteen samples. HFRP confinement was instrumental in driving a notable rise in both ultimate compressive strength and strain. Due to hemp confinement, the ultimate compressive strength saw improvements of up to 272%, while strain improvements reached a maximum of 457%. To determine the ultimate compressive strength and strain of HFRP-confined concrete, this study explored various existing analytical stress-strain models. In comparison to experimental results, a number of strength models yielded close agreement; however, none could accurately predict the ultimate confined strain. A nonlinear regression analysis was carried out to propose equations for anticipating the ultimate compressive strength and strain of HFRP-encased concrete. The proposed expressions successfully mirrored the outcomes of the experimental tests. A procedure for analyzing the stress-strain characteristics of hemp-confined concrete was developed, utilizing the partial replacement of natural coarse aggregates with recycled fired-clay brick aggregates. The experimental and analytically determined stress-strain curves exhibited an exceptional degree of agreement.
In order to accelerate the industrialization of bicomponent fibers, flexible fiber-based devices, and other specialized technical fibers, and to secure the intellectual property rights of inventors, the creation of swift, affordable, and easily verifiable testing approaches is essential to providing direction in the development of relevant testing standards. The present study formulated a quantitative technique that is based on in-situ cross-sectional observation and image analysis. Cross-sections of the fibers were, in the initial stages, swiftly prepared via a non-embedding method. Transmission and reflection metallographic microscopes were used to both capture in-situ observations and cross-section images of the fibers. This in-situ observation permits a prompt characterization of the bicomponent fiber, including its type and spatial distribution. After all, the mass percentage of each component was determined rapidly by AI software, leveraging data from density, cross-section measurements, and the entire set of test samples for each component. A quantitative analysis employing the ultra-depth of field microscope, differential scanning calorimetry (DSC), and chemical dissolution method proved to be a swift, precise, economical, user-friendly, energy-saving, and environmentally responsible process. The intelligent qualitative and quantitative analysis of bicomponent fibers, fiber-based flexible devices, and blended textiles will be significantly advanced by widespread use of this method.
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