Optimization Of Reaction Parameters Research Articles

Molecular precursor route for the phase selective synthesis of α-MnS or metastable γ-MnS nanomaterials for magnetic studies and deposition of thin films by AACVD

Heterocyclic dithiocarbamate complex of manganese and the adducts of the complex with 1,10-phenanthroline and 2,2-bipyridyl respectively were synthesized and characterized. The complexes were used as single-source precursors for the preparation of MnS nanoparticles via thermolysis in oleylamine (OLA) and dodecanethiol (DT). The optimized reaction parameters have resulted in the formation of α-MnS and γ-MnS nanoparticles depending on the dispersion medium and the nature of the precursor. The same precursors were also used for the deposition of MnS thin films by the aerosol-assisted chemical vapour deposition (AACVD) method in varying solvents and temperatures. The morphology and phase of the synthesized nanoparticles were shown to be affected by the precursor type and the nature of the surfactants. TEM images show the formation of nanoparticles of various morphologies ranging from spherical monodispersed to large elongated pointed rods, depending on the precursor type. SEM images showed that the morphology of the deposited thin films is affected by precursor type and the deposition temperature. Worm-like to rod-like films were observed on TEM images at 350 °C, which changes to spherical or cubic films at 450 °C. Magnetic measurements at room temperature showed the α-MnS and γ-MnS nanoparticles in paramagnetic states due to Mn2+ moments. The susceptibility for the γ-phase is at least double that of the α-phase. Finite and small hysteretic effects in low fields are indicative of small ordered antiferromagnetic phases due to negative exchange interaction between Mn2+ ions.

Selective and efficient aerobic oxidation of benzyl alcohols using plasmonic Au-TiO2: Influence of phase transformation on photocatalytic activity

Chemical processes using heterogeneous photocatalytic systems are widely used for the synthesis of valuable fine chemicals. To improve these chemical processes both environmental and energy aspects must be kept in mind for favorable reaction conditions, such as optimum temperature and atmospheric pressure. In this study, plasmonic Au nanoparticles (Au NP) dispersed over TiO2 photocatalyst with different phases of TiO2 (amorphous, anatase and rutile) have been synthesized by using a facile sol–gel method followed by calcination for the photocatalytic oxidation of benzyl alcohol (BnOH) to benzaldehyde (BzH) under visible light irradiation at ambient conditions. The best photocatalyst exhibits high surface area and excellent catalytic conversion efficiency (96%) for the oxidation of BnOH to BzH in less reaction time using a green solvent, acetonitrile at room temperature. The detailed optimization of reaction parameters was performed for alcohol conversion. In addition the corresponding green metrics parameters were also calculated. The photocatalyst also shows excellent stability and reusability for multiple cycles. This work suggests that the Au-TiO2 catalyst provides a novel green and sustainable approach for the selective and efficient aerobic oxidation of BnOH to BzH under visible light irradiation. Furthermore, the impact of different phases of TiO2 on the photocatalytic activity has also been discussed.

Optimisation of reaction parameters for a novel polymeric additives as flow improvers of crude oil using response surface methodology

In recent years, polymeric additives have received considerable attention as a wax control approach to enhance the flowability of waxy crude oil. Furthermore, the satisfactory model for predicting maximum yield in free radical polymerisation has been challenging due to the complexity and rigours of classic kinetic models. This study investigated the influence of operating parameters on a novel synthesised polymer used as a wax deposition inhibitor in a crude oil pipeline. Response surface methodology (RSM) was used to develop a polynomial regression model and investigate the effect of reaction temperature, reaction time, and initiator concentration on the polymerisation yield of behenyl acrylate-co-stearyl methacrylate-co-maleic anhydride (BA-co-SMA-co-MA) polymer by using central composite design (CCD) approach. The modelled optimisation conditions were reaction time of 8.1 h, reaction temperature of 102 °C, and initiator concentration of 1.57 wt%, with the corresponding yield of 93.75%. The regression model analysis (ANOVA) detected an R2 value of 0.9696, indicating that the model can clarify 96.96% of the variation in data variation and does not clarify only 3% of the total differences. Three experimental validation runs were carried out using the optimal conditions, and the highest average yield is 93.20%. An error of about 0.55% was observed compared with the expected value. Therefore, the proposed model is reliable and can predict yield response accurately. Furthermore, the regression model is highly significant, indicating a strong agreement between the expected and experimental values of BA-co-SMA-co-MA yield. Consequently, this study’s findings can help provide a robust model for predicting maximum polymerisation yield to reduce the cost and processing time associated with the polymerisation process.

Strategies toward the Synthesis of Advanced Functional Sorbent Performance for Uranium Uptake from Seawater

A polymer fiber-based adsorbent (AF1) composed of acrylonitrile and itaconic acid functional groups was synthesized by a radiation-induced graft polymerization technique onto hollow-gear shaped polyethylene (PE) fibers. Investigation of the optimum reaction parameters for the conversion of grafted cyano moieties into amidoxime groups was conducted by the reaction with hydroxylamine at different temperatures and periods in a variety of aqueous and organic solvents. The 13C CP/MAS spectra of amidoximated AF1 adsorbent fibers from water–methanol and dimethyl sulfoxide (DMSO) revealed that both the cyclic imide dioxime and open-chain amidoxime were formed through the reaction. The conversion from amidoxime to imide dioxime was found to occur slowly and gradually with the increasing reaction time. The quicker diffusion of DMSO as compared to that of water–methanol, in the grafted trunk PE fiber, resulted in faster kinetics of the amidoximation reaction. The uranium adsorption capacity of the amidoximated AF1 samples was determined after (i) 24 h contact with sodium-based brine spiked with uranium and (ii) 56 days of exposure to filtered seawater (Sequim Bay, WA, USA) in flow-through columns. The uranium extraction performance of the adsorbents after exposure to filtered seawater was consistent with the laboratory screening results, and the amidoximated AF1 samples (in DMSO at 70 °C for 3 h) exhibited the highest 56 day uranium adsorption capacity (5.04 ± 0.15 g U/kg-ads) with faster adsorption kinetics compared to the pristine AF1 adsorbents.

Co2+/PMS based sulfate-radical treatment for effective mineralization of spent ion exchange resin

Sulfate radical advance oxidation processes (SR-AOPs) have attracted a greater attention as a suitable alternative of the hydroxyl radical based advance oxidation process (HR-AOPs). In this study, for the first time we report liquid phase mineralization of nuclear grade cationic IRN-77 resin in Co2+/peroxymonosulfate (PMS) based SR-AOPs. After the dissolution of cationic IRN-77 resin, 30 volatile and 15 semi-volatile organic compounds were analyzed/detected using non-targeted GC-MS analysis. The optimal reaction parameters for the highest chemical oxygen demand (COD) removal (%) of IRN-77 resin were determined, and the initial pH, PMS dosage, and reaction temperature were found to be the most influential parameters for the resin degradation. We successfully achieved ∼90% COD removal (1000 mg/L; 1000 ppm) of dissolved spent resin for SR-AOPs by optimizing the reaction parameters as initial pH = 9, Co2+ = 4 mM (catalyst), PMS = 60 mM (as oxidant) at 60 °C temperature for 60 min reaction. The electron spin resonance spectroscopy (ESR) spectra confirmed the presence of SO4∙- and OH∙ as main reactive species in the Co2+/PMS resin system. In addition, Fourier transform infrared spectroscopy (FT-IR) analyses were used for structural characterization of solid and liquid phase resin samples. We believe that this work will offer a robust approach for the effective treatment of spent resin generated from nuclear industry.

Multiple-objective optimization in green fuel production via catalytic deoxygenation reaction with NiO-dolomite catalyst

This study investigates the multi-objective optimization of reaction parameters with response surface methodology (RSM) with central composite design (CCD) for the deoxygenation of waste cooking oil (WCO) over low cost-modified local carbonate mineral catalyst (NiO-Malaysian dolomite) into green fuel in the range of gasoline, kerosene and diesel. RSM was performed to study the effect of four operating parameters: temperature (390–430 °C), time (30–120 min), catalyst loading (1–10 wt%) and nitrogen flow rate (50–300 cm3/min). The results indicate that for maximum WCO conversion, deoxygenated oil and product yield, the optimum parameters of the deoxygenation reaction were at 410 °C, 60 min, 5.50 wt% of catalyst loading, and 175 cm3/min of N2. The green fuel properties testing (density, kinematic viscosity, flash point, cloud point, pour point, sulfur, carbon residue, cetane index, oxidation stability, acid value, iodine value and calorific value) and GC–MS analysis show that the product oil meets almost all the requirements of green diesel fuel and hydrocarbon biofuel standards for fuel application while the quadratic model proposed agreed with the experimental data (95% confidence) which indicates that the RSM can adequately predict the reaction products.

Recovery of niobium and titanium from ilmenorutile by NaOH roasting-H2SO4 leaching process

Niobium has a wide range of application in various industries such as materials, alloy, and electronic industry. To improve the use of ilmenorutile in China's Bayan Obo deposit, a novel process of extracting niobium, titanium, and iron from ilmenorutile by NaOH roasting-H2SO4 leaching process (NRHLP) was proposed. The influences of roasting and leaching temperature, roasting and leaching time, molar ratio of NaOH-to-ilmenorutile, leaching mass ratio of liquid-to-solid, and the H2SO4 concentration on the extraction of niobium were systematically investigated. The results demonstrate that this process is efficient. The optimized reaction parameters were as follows: roasting temperature, 550 °C; molar ratio of NaOH-to-ilmenorutile, 2.6; roasting time, 120 min; leaching mass ratio of liquid-to-solid, 4.0; leaching temperature, 90 °C; the H2SO4 concentration, 60 wt.%; leaching time, 2 h. Under these optimum circumstances, the maximum niobium and titanium recovery can reach 96.68%. In addition, a new phase containing niobium and titanium is confirmed and proved.

Multi-response optimization of transesterification reaction for biodiesel production from castor oil assisted by hydrodynamic cavitation

With the increasing energy demand, fossil fuel depletion rate is increasing, therefore a need to develop sustainable and energy-efficient biodiesel production systems is arising which can compensate for the rate of fossil fuel depletion. The current study aims to analyze biodiesel production from castor oil using a novel hydrodynamic cavitation reactor. Response surface methodology (RSM) coupled with Box-Behnken design was incorporated to carry out the optimization of reaction parameters (reaction temperature, methanol to oil molar ratio, catalyst amount, and reaction time) to obtain desired castor oil methyl ester (COME) yield, functional exergy efficiency (FEE), Universal exergy efficiency (UEE) and normalized exergy destruction (NED). The developed model shows higher goodness of fit with values of R2 > 99% and R2adj > 98% for all these responses. Desirable reaction conditions for maximum COME yield (92.31 %) were: 57.9 °C temperature, 10.3:1 MeOH:Oil molar ratio, 1.05 %wt. catalyst amount and 58.94 min reaction time whereas based on exergetic indicators along with COME yield using multi-response optimization the same were: 60.3 °C temperature, 9.82:1 MeOH:Oil molar ratio, 1.06 %wt. catalyst amount and 50.86 min reaction time. The COME yield of 93.83 % and 92.27 ± 0.43%, FEE of 86.85% and 85.13 ± 0.40%, UEE of 98.21% and 98.22 ± 0.18%, NED of 0.14 and 0.13 ± 0.01 were predicted and experimentally calculated respectively at optimized reaction conditions considering composite desirability of all the responses. Consideration of exergetic indicators in multi-response optimization using RSM resulted in reduction of reaction time and exergy destruction by 14% and 15% respectively.

Toward the Direct Synthesis of HDPE Powders for Powder Bed Fusion Based Additive Manufacturing

AbstractPowder bed fusion (PBF) suitable polyethylene particles are targeted by means of a direct synthesis, using a bisimino pyridine iron catalyst (BIP FeCl2) supported on microsized silica particles. An active support is generated by treating spray dried silica microparticles with a methyl aluminoxane activated BIP FeCl2 catalyst in toluene. Semibatch ethylene polymerization is mapped with respect to pressure, temperature, and reaction time to find optimal reaction parameters. The optimized synthesis leads to round polyethylene particles with a median size of ≈50 µm which have a sinter window of 8–15 °C and an unconfined yield stress (ffc) of 1.5 in a ring shear tester. The Young modulus of injection molded samples is in the range of 150–250 Pa with an elongation at break of about 30%. The powder flowability is improved by coating with nanosilica powder to an ffc of 3.8. Additivitation with carbon black allows to laser sinter the powder to solid parts in a small scale adapted setup for selective laser sintering (PBF/laser beam (LB)/P). Severe caking is preventing the preparation of CAD model conform parts. Commercial HDPE powder for PBF is additivated the same way to give substantially solid built parts, but with similar caking.

Assessment of acid resistance of natural pozzolan-based alkali-activated concrete: Experimental and optimization modelling

Although the synthesis and properties of natural pozzolan (NP)-based alkali-activated binder (AAB) have been investigated, to the best of our knowledge, no study has focused on and assessed the performance of such concrete when exposed to acid attack. In addition, there is a lack of information regarding the optimisation of reaction parameters. Therefore, in the present study, NPs blended with nano-silica (nSiO2) from 0 to 7.5% were taken into account to develop alkali-activated concrete (ACC), cured at room temperature, and subsequently exposed to 5% sulfuric acid (H2SO4aq). The performance of the NP/nSiO2-based ACC was evaluated by visual examination, microstructure, weight loss, and compressive strength loss up to one year of exposure to an acidic environment. In addition, artificial neural network (ANN) and response surface methodology (RSM) models were developed to predict and optimize nSiO2 to ascertain the minimum weight and strength loss. Based on both the predicted and actual results, a significant improvement in the microstructure was achieved with an increase in nSiO2. The micro-analytical examination revealed the leaching of vital elements from the binder structure, such as Al, Ca, and Na, which enabled the creation of highly expansive substances such as gypsum, which caused cracking and eventually disintegration in the OPC and NP-based AAB incorporating lower quantities of nSiO2. Both the loss in weight and strength were in the range of 23%–39% in the 1% to 7.5% nSiO2 modified AAC. In contrast, in the control AAC and OPC-based concrete, a weight loss of more than 50% was recorded, along with a substantial reduction in strength.

Selective hydrogenation of cinnamaldehyde to cinnamyl alcohol over palladium/zirconia in microwave protocol

Hydrogenation of aldehydes (RHO) is one of the frequently used reactions in organic synthesis and pharmaceuticals industries. In this contribution, we have synthesized control shaped and nano-sized tetragonal zirconia (t-ZrO2), palladium supported on zirconia (Pd/t-ZrO2) and nickel promoted palladium supported on zirconia (Ni-Pd/t-ZrO2) though modified microwave irradiation method. All the prepared samples were characterized by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), X-ray Diffractometry (XRD), Thermal Gravimetric Analysis (TGA), Brunauer-Emmett-Teller (BET) surface area and pore size analysis, and Fourier Transform Infrared Spectroscopy (FT-IR). Theoretical calculation (DFT) revealed high interaction of Pd with t-ZrO2(101) surface. Furthermore, adsorption energy, support relaxation and charge transfer studies confirmed the stability of Pd on t-ZrO2(101) surface. The catalytic activity of catalysts was tested for cinnamaldehyde (CAL) hydrogenation in a modified microwave reactor. The comparative study of microwave irradiated (MW) and conventional heating (C-Heating) systems show supremacy of MW over C-Heating by a factor of 46% under optimal reaction parameters for Pd/t-ZrO2 catalyst. The stability, life span, conversion and selectivity of Pd/t-ZrO2 under MW system suggest the applicability of the catalysts for a variety of organic hydrogenation reactions.

Triphenylphosphine-Assisted Transformation of NiS to Ni2P through a Solvent-Less Pyrolysis Route: Synthesis and Electrocatalytic Performance.

Straightforward synthetic routes to the preparation of transition metal phosphides or their chalcogenide analogues are highly desired due to their widespread applications, including catalysis. We report a facile and simple route for the preparation of a pure phase nickel phosphide (Ni2P) and phase transformations in the nickel sulfide (NiS) system through a solvent-less synthetic protocol. Decomposition of different sulfur-based complexes (dithiocarbamate, xanthate, and dithiophosphonate) of nickel(II) was investigated in the presence and absence of triphenylphosphine (TPP). The optimization of reaction parameters (nature of precursor, ratio of TPP, temperature, and time) indicated that phosphorus- and sulfur-containing inorganic dithiophosphonate complexes and TPP (1:1 mole ratio) produced pure nickel phosphide, whereas different phases of nickel sulfide were obtained from dithiocarbamate and xanthate precursors in the presence or absence of TPP. A plausible explanation of the sulfide or phosphide phase formation is suggested, and the performance of Ni2P was investigated as an electrocatalyst for supercapacitance and overall water-splitting reactions. The performance of Ni2P with the surface free of any capping agents is not well explored, as common synthetic methods are solution-based routes; therefore, the electrocatalytic performance was also compared with metal phosphides, prepared by other routes. The highest specific capacitance of 367 F/g was observed at 1 A/g, and the maximum energy and power density of Ni2P were calculated to be 17.9 Wh/kg and 6951 W/kg, respectively. The prepared nickel phosphide required overpotentials of 174 and 316 mV along with Tafel slopes of 115 and 95 mV/dec to achieve a current density of 10 mA/cm2 for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), respectively.

Determination of optimum reaction and process control parameters of starch conversion in maltose syrup production

In maltose syrup production, one of the critical processing stages is the starch conversion process. During this process, the reaction time and enzyme concentrations are two important parameters to obtain the standard sugar spectrum. The purpose of this study is; i) to find optimum reaction time and enzyme concentrations during the starch conversion process, ii) to determine process control and dynamic parameters during the starch conversion process in the maltose syrup production. The different amounts of beta and alpha-amylase enzymes (0.10, 0.15, 0.20 and 0.25 ml of β-amylase; 0.03, 0.05, 0.07 and 0.09 ml of α-amylase) were used to determine the optimum concentrations and time. pH, Brix and the concentrations of sugars (dextrose, maltose, maltotriose (DP3) and high sugars (DPN)) were determined. It was found that the enzyme concentration, ratios of the enzyme used and reaction time significantly affect the starch conversion process. The mixture containing 0.20 ml β-amylase and 0.05 ml α-amylase was determined as the optimum value (P≤0.05). It was found that the maximum process gains were obtained at 0.1 ml β-amylase and 0.03 ml α-amylase, 0.25 ml β-amylase and 0.03 ml α-amylase, 0.2 ml β-amylase and 0.03 ml α-amylase for dextrose, maltose, DP3 and DPN, respectively.

Effective Chemical Vapor Deposition and Characterization of N-Doped Graphene for High Electrochemical Performance.

Here we reports an effective synthetic method for the preparation of N-graphene upon thermal annealing of prepared graphene oxide in the existence of ammonia. N-doped graphene oxide was analysed using different characterization techniques like X-ray diffraction, field emission scanning electron microscopy, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. The nitrogen atom showed good binding with the graphene sheets, that are analysed by the X-ray photoelectron spectroscopy. The synthesized N-graphene have shown higher thermal stability compared with GO and graphene. The elcerochemnical performance like Cyclic voltammetry as well chronopotentiometry charge-discharge calculations revealed that the N-doped graphene exhibits remarkable behaviour favors a specific capacitance value about 209 F g-1 at 5 mV s-1 and 270 F g-1 for 1 A g-1 applied current density including outsanding charge-discharge stability about 98% of the initial capacitance subsequent 1000 cycles at 5 A g-1. The N-content in the graphene material with the optimized reaction parameters potentially improved electrode active material for energy storage applications.

Iron Oxide (Fe3O4)-Supported SiO2 Magnetic Nanocomposites for Efficient Adsorption of Fluoride from Drinking Water: Synthesis, Characterization, and Adsorption Isotherm Analysis

This research work reports the magnetic adsorption of fluoride from drinking water through silica-coated Fe3O4 nanoparticles. Chemical precipitation and wet impregnation methods were employed to synthesize the magnetic nanomaterials. Moreover, the synthesized nanomaterials were characterized for physicochemical properties through scanning electron microscopy, Fourier-transform infrared spectroscopy, and X-ray powder diffraction. Screening studies were conducted to select the best iron oxide loading (0.0–1.5 wt%) and calcination temperature (300–500 °C). The best selected nanomaterial (0.5Fe-Si-500) showed a homogenous FeO distribution with a 23.79 nm crystallite size. Moreover, the optimized reaction parameters were: 10 min of contact time, 0.03 g L−1 adsorbent dose, and 10 mg L−1 fluoride (F−) concentration. Adsorption data were fitted to the Langmuir and Freundlich isotherm models. The Qm and KF (the maximum adsorption capacities) values were 5.5991 mg g−1 and 1.869 L g−1 respectively. Furthermore, accelerated adsorption with shorter contact times and high adsorption capacity at working pH was among the outcomes of this research work.

Droplet Cas12a Assay Enables DNA Quantification from Unamplified Samples at the Single-Molecule Level.

DNA quantification is important for biomedical research, but the routinely used techniques rely on nucleic acid amplification which have inherent issues like cross-contamination risk and quantification bias. Here, we report a CRISPR-Cas12a-based molecular diagnostic technique for amplification-free and absolute quantification of DNA at the single-molecule level. To achieve this, we first screened out the optimal reaction parameters for high-efficient Cas12a assay, yielding over 50-fold improvement in sensitivity compared with the reported Cas12a assays. We further leveraged the microdroplet-enabled confinement effect to perform an ultralocalized droplet Cas12a assay, obtaining excellent specificity and single-molecule sensitivity. Moreover, we demonstrated its versatility and quantification capability by direct counting of diverse virus's DNAs (African swine fever virus, Epstein-Barr virus, and Hepatitis B virus) from clinical serum samples with a wide range of viral titers. Given the flexible programmability of crRNA, we envision this amplification-free technique as a versatile and quantitative platform for molecular diagnosis.

Gram-scale synthesis of ZnS/NiO core-shell hierarchical nanostructures and their enhanced H2 production in crude glycerol and sulphide wastewater

Design and development of the efficient and durable photocatalyst that generates H2 fuel utilizing industrial wastewater under solar light irradiation is a sustainable process. Innumerable photocatalysts have been reported for efficient H2 production, but their large-scale production with the same efficiency of H2 production is a challenging task. In this study, a few gram-scale syntheses of ZnS wrapped with NiO hierarchical core-shell nanostructure via the surfactant-mediated process has been reported. Morphology and crystal structure analysis of ZnS/NiO showed spherical shaped hierarchical core-shell with cubic and face-centered cubic crystal structures. The surface examination confirmed the presence of Zn2+, S2−, Ni2+ and O2− ions in the nanocomposite. The photocurrent and photoluminescence studies of pristine and nanocomposites revealed that core-shell material is non-corrosive with a prolonged life-time of photo-excitons. Parametric studies on photocatalytic H2 generation in lab-scale photoreactor using crude glycerol in water recorded a high rate of H2 generation of 9.3 mmol h−1.g−1 of catalyst under the simulated solar light irradiation. Optimized reaction parameters are extended to a demonstrative photoreactor containing aqueous crude glycerol produced 18.5 mmol h−1 of H2 generation under the natural solar light irradiation. The same nanostructures were further tested with the simulated sulfide wastewater and the optimized catalyst showed H2 production of 350 mL h−1. The experimental results of time-on stream and catalytic stability demonstrated that ZnS/NiO hierarchical core-shell nanostructures can be recyclable and reusable for the continuous photocatalytic H2 generation.

Poly(lactic acid)/vermiculite‐g‐polyisoprene nanocomposites based on thiol‐ene click chemistry: performance, shear crystallization and Rheonaut technology analysis

AbstractVermiculite (VMT) grafted polyisoprene (PIP) (VMT‐g‐PIP) was synthesized by thiol‐ene click chemistry. An orthogonal experiment and range analysis showed that the optimum reaction parameters of VMT‐g‐PIP were as follows: reaction time 9 h, reaction temperature 60 °C, initiator azodiisobutyronitrile dosage 0.025 g and mass ratio of isoprene to VMT‐SH 3:1. Due to the strong interfacial compatibility between poly(lactic acid) (PLA) and VMT‐g‐PIP, the impact strength and elongation at break of PLA/VMT‐g‐PIP (0.7 wt%) nanocomposites were increased by 1.33 and 5.20 times, respectively, compared with pure PLA. Thermogravimetric analysis and cone calorimeter analysis demonstrated that the thermal stability and fire resistance effect of PLA/VMT‐g‐PIP nanocomposites had been improved to a certain extent. Differential scanning calorimetry and Rheonaut technology for simultaneous rheometry and Fourier transform infrared spectroscopy demonstrated that the synergistic effect of shear field and heterogeneous nucleation of VMT‐g‐PIP induced faster crystallization of PLA. Accordingly, the crystallization properties of PLA were clearly improved, which enhanced its toughness. Enzymatic degradation behavior showed that VMT‐g‐PIP inhibited the biodegradation of PLA to a certain extent. © 2021 Society of Industrial Chemistry.

Laser-Driven Growth of Semiconductor Nanowires from Colloidal Nanocrystals.

Semiconductor nanowire production through vapor- and solution-based processes has propelled nanowire systems toward a wide range of technological applications. Although vapor-based nanowire syntheses enable precise control over nanowire composition and phase, they typically employ batch processes with specialized pressure management systems, limiting throughput. Solution-based nanowire growth processes have improved scalability but can require even more extensive pressure and temperature management systems. Here, we demonstrate a solution-based nanowire growth process that utilizes the large Young-Laplace interfacial surface pressures and collective heating effects of colloidal metal nanocrystals under irradiation to drive nanowire growth photothermally. Laser irradiation of a solution containing metal nanocrystals and semiconductor precursors facilitates rapid heating, precursor decomposition, and nanowire growth on a benchtop in simple glassware under standard conditions, potentially enabling a range of solution-based experiments including in-line combinatorial identification of optimized reaction parameters, in situ measurements, and the production of nanowires with complex compositions.

Multifunctional Activities of Gold Nanoparticles Biosynthesized Using Bacteria Isolated from Mining Areas

Research on gold nanoparticles (AuNPs) has often focused on their physical, chemical, and crystalline characteristics. Commercial AuNPs have been applied in the diverse fields of biomedicine, catalysis, photovoltaics, and sensing. In this study, we explored the various activities of AuNPs to widen their applicability. This paper presents a simple and rapid synthesis process of AuNPs with bacteria isolated from a gold mining area. We also investigated the optimization of reaction parameters for AuNP synthesis. The study results revealed that among the isolated strains, Bifidobacterium lactis and Escherichia coli demonstrated the highest capabilities of AuNP synthesis. The optimal pH values for AuNP synthesis by B. lactis (BLAuNPs) and E. coli (ECAuNPs) were 5.0 for 72 h of incubation and 8.0 for 24 h of incubation. The average particle sizes of ECAuNPs and BLAuNPs were 4.2 and 5.6 nm, respectively. Furthermore, these biogenic AuNPs were found to be stable with no aggregation after 3 months of storage. BLAuNPs and ECAuNPs exhibited high levels of antimicrobial, antioxidant, photocatalytic, and antityrosinase activity. Moreover, they were noncytotoxic to skin cells even at 100% melanin inhibitory concentrations. Considering the demonstrated multifunctional activities of AuNPs, BLAuNPs and ECAuNPs have promising potential for commercialization.