Antisolvent Recrystallization Research Articles

Synthesis, Structural, Morphological, and Optical Properties of Promising Lead-Free Double Perovskite Na2CuBiBr6: A Sustainable Material for Photovoltaic Applications

This work primarily focuses on synthesizing and evaluating the structure, morphology, and optical features of double perovskite Na2CuBiBr6 forphotovoltaic devices. In the present investigation, Na2CuBiBr6 is created by a solution-based antisolvent recrystallization approach. A comprehensive experimental investigation is conducted on the Na2CuBiBr6 double perovskite, encompassing its structural configuration, morphology, and optical features. X-ray diffraction analysis verifies the creation of Na2CuBiBr6 double perovskite and showcases its exceptional phasestability in the cubic phase. Scanning electron microscopy reveals the presence of multidirectional crystals ofNa2CuBiBr6crystals. The presence of polycrystalline cubic Na2CuBiBr6 is confirmed using transmission electron microscopy and electron diffraction investigation. In addition, energy-dispersive X-ray spectroscopy demonstrates the consistent distribution of elements within Na2CuBiBr6. UV–vis spectroscopy reveals a band gap of 1.37 eV. The optical characteristics demonstrate that Na2CuBiBr6 exhibits a greater absorbance level and a lower reflectivity level within the visible spectrum. The results of this study suggest that the Na2CuBiBr6 double perovskite, which is both lead-free and environmentally benign, has significant potential for applications in photovoltaic and thermoelectric devices.

Self‐Powered Cs3Bi2I9/ZnO Heterojunction Photodetector with Dual‐Band Photoresponse

AbstractCs3Bi2I9/ZnO heterostructures are constructed by the growth of Cs3Bi2I9 layer onto the spin‐coated ZnO films by a modified antisolvent recrystallization method, a series of Cs3Bi2I9/ZnO heterojunction photodetectors (PDs) with varied growth times of Cs3Bi2I9 layer are fabricated. The construction of Cs3Bi2I9/ZnO heterojunction contributes to their improved photoelectric performance compared to ZnO‐based PD, and the Cs3Bi2I9 layer thickness plays an important role in tuning the photoelectric performance of these PDs. At 405 nm and 0 V bias, the optimized 6‐Cs3Bi2I9/ZnO PD generates a high photocurrent of −3.03 µA, a medium on/off ratio of 144.3, and a short response time of 16.4 ms/16.8 ms. It also exhibits superior dual‐band self‐powered photoresponse with two responsivity and detectivity peaks at 380 nm in the UV region and at 430 nm in the visible light region. At 380 nm, this PD presents the highest responsivity of 33.2 mA W−1 and detectivity of 1.07 × 1010 Jones. It is believed that the optimized growth of the Cs3Bi2I9 layer generates a depletion layer with suitable thickness near the interface, and the as‐promoted charge‐carrier separation and transport result in improved self‐powered properties. The rational construction of perovskite‐based heterojunction has proved as an efficient way to achieve self‐powered photodetection.

Particle Processing of Acetaminophen Using the Cooling and Anti-solvent Crystallization Methods

Several crystallization strategies are being implemented to enhance the solubility of acetaminophen, also known as paracetamol. Therefore, this study aimed to determine the effectiveness of the cooling and anti-solvent crystallization on the properties of acetaminophen. The results showed that the anti-solvent recrystallization produced achieved an impressive yield of up to 41.40%, while the cooling method yielded approximately 2–9%. Through FTIR, XRD, and DSC analysis on the samples, it was discovered that these methods had minimum effects on the molecular and thermal properties of the compound. Furthermore, the methods did not alter the crystallinity of acetaminophen, with crystal form I dominating the products. In addition, processing using the cooling and anti-solvent effectively reduced particle size of acetaminophen from 68.60 μm to 26.92 μm and 28.25 µm, respectively. In conclusion, the solubility of paracetamol in aqueous solutions experienced a significant enhancement. In the unprocessed samples, it measured 0.0107 gram/ml, while the recrystallized samples had an improved range of 0.0123 to 0.0167 g/ml.

Synthesis of Double Trivalent Perovskite Quantum Dots Cs3BiSbX9 (X=Cl, Br, I) for Efficient CO2 Photoreduction Performance.

Non-toxic Bi halides have great potential in the field of CO2 photoreduction, but strong charge localization limits their charge separation and transfer. In this study, a series of Cs3BiSbX9 (X=Cl, Br, I) perovskite quantum dots (PQDs) are synthesized by antisolvent recrystallization at room temperature, in which Cs3BiSbBr9 PQDs has high selectivity (94.51%) and yield (15.32µmolg-1h-1) of CO2 to CO. In situ DRIFTS and theoretical calculations suggest that the surface charge can be tailored by halogen modulation, allowing for the customization of intermediate species. The Bi─Br─Sb symmetric charge distribution induced by the halogen Br promotes the formation of b─HCOO and reduces the reaction energy barrier of the rate-limiting step, while the weak electronegativity of Cl and the high electronegativity of I leads to m─HCOO and ─COOH production, which are detrimental to CO generation. This work provides new insights into the design of halide alloy perovskites for CO2 photoreduction.

Novel Synthesis of radioluminescent CsI:Tl microcrystals under ambient conditions by antisolvent recrystallization method

Thallium doped Cesium Iodide (CsI:Tl) radioluminescent microcrystals are promising candidate for scintillation applications that include medical imaging, nuclear safety and high energy particle detection applications. This paper introduces, for the very first time, an antisolvent recrystallization method to synthesize microcrystals of CsI:Tl. The antisolvent recrystallization method is useful for synthesizing microcrystals at room temperature under atmospheric pressure and humidity conditions with high product yield approaching ∼90 %. The polycrystalline nature of the CsI:Tl microcrystals is confirmed from the X-ray diffraction analysis, wherein the crystallite size is found to be in the range of 20–25 nm. The scanning electron microscopy revealed the size of microcrystals in the range of 1–13 μm. The doping concentration of thallium (with 0.06, 0.10, 0.20, 0.50 and 1.00 mol%) strongly affects the luminescence yield. At higher concentration of doping, a shift towards long wavelength is observed. The strongest luminescence yield is observed in the sample of 0.2 mol% Thallium doping, which is around 76 % of luminescence compared to single crystal of CsI:Tl. This work provides a low-cost alternative to the growth of radioluminescent microcrystals in comparison with the existing single crystal growth approaches.

Mixed Halide Formation in Lead‐Free Antimony‐Based Halide Perovskite for Boosted CO2 Photoreduction: Beyond Band Gap Tuning

AbstractPhotocatalytic conversion of carbon dioxide (CO2) into value‐added fuels is a vastly promising anthropogenic chemical carbon cycle to combat the greenhouse effect while meeting the ever‐increasing energy demand. Recently, lead‐based halide perovskites have demonstrated great potential in various applications including photochemical reduction of CO2. However, in view of lead toxicity, the exploration of a lead‐free alternative is crucial for long term application. Herein, a series of lead‐free mixed halide perovskites Cs3Sb2ClxBr9−x (0 ≤ x ≤ 9) is prepared via a facile antisolvent recrystallization technique, where the incorporation of a secondary halide enhances the charge transfer and separation while allowing precise tuning of bandgap between 2.59 and 2.90 eV. Theoretical calculations further reveal that the formation of mixed Cl/Br halides engenders favorable charge redistribution due to lower octahedral distortion, which in turn strengthens CO2 adsorption and activation. Under visible light illumination, the optimal dual halide perovskite, Cs3Sb2Cl4Br5 manifests substantial twofold and fourfold enhancements of CH4 yield over the single halide perovskite, Cs3Sb2Br9 and Cs3Sb2Cl9, respectively. In brief, this study provides a compelling demonstration of lead‐free mixed halide perovskites for photocatalytic CO2 reduction, and it is anticipated to drive further application of perovskite‐based photocatalysts toward a diverse range of artificial photoredox reactions.

Nano-crystallization of flubendazole for enhanced dissolution rate and improved in vivo efficacy against Trichinella spiralis

The aim was to enhance the dissolution rate and in vivo efficacy of flubendazole against trichinella spiralis. Flubendazole nanocrystals were developed by controlled anti-solvent recrystallization. Saturated flubendazole solution was prepared in DMSO. This was injected into phosphate buffer (pH 7.4) containing Aerosil 200, Poloxamer 407 or sodium lauryl sulphate (SLS) while mixing using paddle mixer. The developed crystals were separated from DMSO/aqueous system by centrifugation. The crystals were characterized using DSC, X-ray diffraction and electron microscopy. The crystals were suspended in Poloxamer 407 solution and dissolution rate was monitored. Optimal formulation was administered to Trichinella spiralis infected mice. Administration protocol attacked the parasite in intestinal, migrating and encysted phases. The crystals were spherical nanosized with formulation employing 0.2% Poloxamer 407 as stabilizer being optimum with size of 743.1 nm. DSC and X-ray supported particle size reduction with partial amorphization. Optimal formulation showed fast dissolution to deliver 83.1% after 5 min. Nanocrystals provided complete eradication of intestinal Trichinella and reduced larval count by 90.27 and 85.76% in migrating and encysted phases compared with marginal effect in case of unprocessed flubendazole. The efficacy was clearer from improved histopathological features of the muscles. The study introduced nano-crystallization for enhanced dissolution and in vivo efficacy of flubendazole.

Preparation and in vitro evaluation of hesperidin nanoparticles by antisolvent recrystallization in a double homogenate system.

Hesperidin nanoparticles (HNPs) were made for the first time employing an antisolvent recrystallization technique in a double homogenate system with positive and negative clockwise rotation in order to completely use the underutilized nutritional components in citrus peel. Dimethyl sulfoxide (DMSO), ethanol, and deionized water were used as the solvents and antisolvents in the hesperidin solution preparation. Hesperidin solution concentration of 60.26mg/mL, homogenization speed of 8257rpm, antisolvent-to-solvent volume ratio of 6.93mL/mL, and homogenization time of 3.15min were the ideal experimental conditions. HNPs have to be at least 72.24nm in size. The structures of the produced hesperidin samples and the raw hesperidin powder were identical, according to the findings of the FTIR, XRD, and TG characterization tests. The HNP sample had an in vitro absorption rate that was 5.63 and 4.23 times greater than that of the raw hesperidin powder, respectively. It was discovered that DMSO was more suited than ethanol for creating HNP particles. In the realms of dietary supplements, therapeutic applications, and health promotion, the HNPs produced by the ARDH technology would be a potential formulation on increasing uses for a wider range of nutraceuticals (synergistic).

Cs2AgBiCl6: a novel, high-efficient and stable visible-light photocatalyst for degradation of organic dyes.

In the past decades, great efforts have been made to develop novel visible-light photocatalysts to achieve high photocatalytic efficiency by utilizing visible light, the largest proportion of solar energy. As a new type of photocatalyst materials, all-inorganic lead-free halide double perovskites have begun to attract widespread interest. Herein, double perovskite Cs2AgBiCl6 was developed into a visible-light photocatalyst for degrading organic dyes. Cs2AgBiCl6 was prepared by the hydrochloric acid precipitation and anti-solvent recrystallization methods, respectively, and was used to degrade organic dyes under visible light. Samples prepared by the anti-solvent recrystallization method are smaller than those prepared by the hydrochloric acid precipitation method, which can degrade 95.7% of Sudan III in 10 min and show excellent photocatalytic activity. The cyclic experiments demonstrate that Cs2AgBiCl6 has a good cycle stability. Moreover, Cs2AgBiCl6-AS also exhibits good photocatalytic degradation ability for Methyl red and Malachite green. These distinctive results indicate that Cs2AgBiCl6 may be a promising material for developing novel, high-efficient and stable visible-light photocatalysts.

Highly stable lead-free Cs2AgBiI6-GO composite photocatalysts for efficient organic pollutant degradation

The use of halide perovskites as photocatalysts has attracted more and more attention. However, the instability and toxicity of the lead halide perovskites have hindered their practical large-scale application. Herein, lead-free Cs2AgBiI6 double perovskite was synthesized by a simple antisolvent recrystallization approach for photocatalysis. Meanwhile, in order to solve the limited photocatalytic performance problem of the pure metal halide perovskites, for the first time, we designed and prepared highly stable Cs2AgBiI6-Graphene oxide (GO) composite photocatalyst. The photodegradation rate of Sudan Red III by Cs2AgBiI6-GO was found to be as high as 85% after 100 min of light irradiation, which was twice that of the pure Cs2AgBiI6 and also more efficient than recently reported photocatalysts under comparable conditions. This work demonstrated that the GO with unique physicochemical properties could prevent the photocatalyst agglomeration and provide charge carrier transport channel to inhibit electron-hole recombination to improve the overall photocatalytic performance.

Synthesis and study of CsPbBr3 by using antisolvent recrystallization method for solar cell applications

Synthesis and study of CsPbBr3 by using antisolvent recrystallization method for solar cell applications

Extraction and purification of paeonol from Moutan Cortex by a combined method of steam distillation and antisolvent recrystallization to reduce energy consumption and carbon dioxide emissions

AbstractThis study aimed to obtain paeonol with high purity by using the combination of steam distillation and antisolvent recrystallization (ASR) and to reduce the energy consumption and CO2 emission in the preparation process. First, different experimental parameters were optimized by response surface methodology (RSM). Under the optimal conditions, the purity and yield of the as‐obtained paeonol were about 98% and 56.97%, respectively. The physicochemical properties of purified paeonol were tested, showing consistency with those of standard paeonol. The energy consumption and CO2 emission of the preparation process of ASR and single‐solvent recrystallization were also investigated. Results showed that the energy consumption and CO2 emission of ASR were about 4.41 J/mg and 0.006 kg/mg, respectively, which were 6.89 J/mg and 0.0095 kg/mg lower than those of ethanol recrystallization, respectively, and 50.22 J/mg and 0.0144 kg/mg lower than methanol those of recrystallization, respectively. The above results showed that ASR could obtain paeonol with high purity in a high‐efficiency, low‐energy, and environmentally protective manner.

Genistein microparticles prepared by antisolvent recrystallization with low-speed homogenization process

To create genistein particles, a brand-new antisolvent recrystallization technique was employed. The response surface approach was utilized to optimize the single factor test findings, which were acquired via the preliminary tests. The ideal liquid-to-liquid ratio was 9, the solution concentration was 21 mg/mL, the nozzle diameter was 700 μm, the feed rate was 39.65 mL/min, and the homogenization rate was 1500 rpm. The smallest mean particle size measured was 202.782 nm. SEM was used to study the powder's morphology, while thermal analysis and infrared imaging were used to evaluate its characteristics. The homogeneous antisolvent recrystallization method-prepared GMP has a better dissolving rate and stronger antioxidant activity when compared to genistein powder. The antisolvent recrystallization approach used in this study, which uses low-speed homogenizing instead of conventional grinding and homogenizing, can successfully reduce particle size, improve bioavailability, and use less energy. This topic may thus be made popular because it has real-world applications.

Separation and Purification of Taxanes from Crude Taxus cuspidata Extract by Antisolvent Recrystallization Method

Taxanes are natural compounds with strong antitumor activity. In this study, we first enriched taxanes by ultrasonic extraction and liquid–liquid extraction from Taxus cuspidata, then purified these taxanes by the antisolvent recrystallization method, and discussed the effects of four recrystallization conditions on the purity of eight target compounds. The most promising purification results were obtained using methanol as a solvent and water as an antisolvent. Response surface methodology (RSM) was used to further optimize the optimal purification conditions: when the crude extraction concentration was 555.28 mg/mL, an antisolvent to solvent volume ratio was 28.16 times, the deposition temperature was 22.91 °C, and the deposition time was 1.76 min, the purity of the taxanes reached its maximum. The scanning electron microscopy (SEM) results showed that recrystallization could effectively reduce the particle size of crude Taxus cuspidata and control the particle morphology. X-ray diffraction (XRD) and Raman spectrum experiments demonstrated that the amorphous state of the crude Taxus cuspidata did not change during the recrystallization process, and always remained amorphous. This recrystallization method can effectively improve the purity of taxanes in Taxus cuspidata, and is suitable for the preliminary purification of taxanes.

Inorganic Copper-Based Halide Perovskite for Efficient Photocatalytic CO2 Reduction.

In view of the toxicity of the Pb element, exploring eco-friendly Pb-free halide perovskites with excellent photoelectric properties is of great research and practical application significance. Herein, copper-based halide perovskite CsCuCl3 and the corresponding Br--substituted sample (CsCuCl2Br) are designed and explored as the catalysts for photocatalytic CO2 reduction for the first time. A facile antisolvent recrystallization process with pre-prepared single crystals as the precursor is employed to controllably synthesize CsCuCl3 and CsCuCl2Br microcrystals (MCs). The electronic structure and charge transfer property analysis by theoretical and experimental investigation reveal that CsCuCl3 possesses a satisfying bandgap (1.92 eV) and conduction band minimum (CBM) to harvest the sunlight and drive the conversion of CO2 to CH4 and CO. The Br- substitution can not only narrow the bandgap but also facilitate the transportation of charge carriers. Thus, a total electron consumption rate of 44.71 μmol g-1 h-1 is achieved for CsCuCl2Br MCs, which is much better than that of same-sized CsPbBr3 microcrystals or even better than many perovskite nanocrystal photocatalysts. This study suggests that Cu-based perovskites can serve as promising candidates for artificial photosynthesis or other photocatalytic applications, which may propose a new thought to construct lead-free, low-cost photocatalysts.

Naringenin Ultrafine Powder Was Prepared by a New Anti-Solvent Recrystallization Method.

Raw naringenin directly isolated from plants is significantly limited by its poor dissolution rate and low bioavailability for clinical and in vivo studies. This study reported a method for the preparation of naringenin ultrafine powder (NUP) using a novel anti-solvent recrystallization process; preliminary experiments were conducted using six single-factor experiments. The response surface Box–Behnken (BBD) design was used to optimize the level of factors. The optimal preparation conditions of the DMP were obtained as follows: the feed rate was 40.82 mL/min, the solution concentration was 20.63 mg/mL, and the surfactant ratio was 0.62%. The minimum average particle size was 305.58 ± 0.37 nm in the derived optimum conditions. A scanning electron microscope was used to compare and analyze the appearance and morphology of the powder before and after preparation. The characterization results of FTIR, TG and XRD showed that no chemical change occurred in the powder before and after preparation. Through the simulated gastrointestinal juice digestion experiment, it was confirmed that the absorption rate of NUP was 2.96 times and 4.05 times higher than raw naringenin, respectively. Therefore, the results showed that the reduction in the particle size through the use of low-speed recrystallization could improve the absorption rate and provided a feasible approach for the further applications.

Antioxidative Activity Evaluation of High Purity and Micronized Tartary Buckwheat Flavonoids Prepared by Antisolvent Recrystallization.

Tartary buckwheat, a healthy food, is associated with a reduced risk of certain human chronic diseases. However, the bioactive component flavonoids in Tartary buckwheat have poor solubility and low absorption in vivo. To improve these points, 60.00% Tartary buckwheat total flavonoids (TFs) were obtained by ethanol refluxing method, which were purified and micronized by antisolvent recrystallization (ASR) using methanol as a solvent and deionized water as an antisolvent. By using High Performance Liquid Chromatography (HPLC) and electrospray ionized mass spectrometry (ESI-MS), the main flavonoid in pure flavonoids (PF) were rutin (RU), kaempferol-3-O-rutinoside (KA) and quercetin (QU); the content of TF is 99.81% after purification. It is more worthy of our attention that micronized flavonoids contribute more to antioxidant activity because of good solubility. These results provide a theoretical reference for the micronization of other flavonoids.

Understanding particle formation in a moving droplet using the classical theory of nucleation and diffusion-based growth mechanism: A modeling approach

Particle size reduction of the active pharmaceutical ingredients (APIs) in the range of 1–5 µm is required for efficient drug delivery through the nasal route. The traditional micronization techniques such as jet milling, spray drying and liquid antisolvent recrystallization exist to produce the particles in this size range. However, these techniques have many disadvantages such as irregular particles, broad particle size distribution, chemical and thermal degradation. Supercritical fluid-based micronization techniques have been proved as a promising technology to produce spherical particles in this size range. In this work, a model is developed to predict the particle size distribution of API recrystallized by a supercritical antisolvent recrystallization process. Rifampicin is considered a modal API to be recrystallized. In this process, the API is first dissolved in dimethyl sulfoxide and this solution is sprayed into a precipitator. The precipitator has carbon dioxide at supercritical conditions i.e. above its critical temperature and pressure. Supercritical Carbon dioxide acts as an antisolvent as rifampicin is not soluble in it. Diffusion of carbon dioxide into solution droplet decreases the solubility of rifampicin in dimethyl sulfoxide and the crystallization process starts. Primary nucleation and diffusion-based growth mechanism are considered to calculate average particle size and particle size distribution. This model is solved in MATLAB 7.1 and the trend of particle size distribution predicted by the model is found to be similar to particle size distribution by experiments.

Experimental investigation of chiral melting phase diagrams in high-pressure CO2 containing organic modifiers

A measurement method suitable to investigate the melting behavior of solid mixtures in a high-pressure, co-solvent–modified CO2 atmosphere was developed, using a variable volume, high-pressure view-cell. The solid sample is added after loading the organic solvents and pressurizing the cell with CO2. Investigation of the melting behavior was done by a first-and-last melting point method at 16 MPa pressure. The melting point depression depended on the organic modifier (being acetonitrile or the 7:3 mixture of cyclohexane and isopropyl acetate). Adding acetonitrile in 2% to the carbon dioxide atmosphere shifted the chiral melting phase diagram of 3-chloromandelic acid by approx. 8–10 °C compared to the values measured earlier in pure carbon dioxide at the same pressure. The eutectic composition of the racemic compound remained unchanged (around 70–75% ee), which is comparable to the limiting composition observed in our earlier antisolvent recrystallization results aiming the enantiomeric purification of the model molecule.

Investigation on crystallization phenomena with supercritical carbon dioxide (CO2) as the antisolvent

Abstract The supercritical antisolvent (SAS) recrystallization process is one of the most promising recrystallization techniques for the particle formation of pharmaceutical compounds. In this process, a solution of active pharmaceutical ingredient (API) is sprayed into the supercritical carbon dioxide (SC CO2) environment. The mass transport of both the solvent and the antisolvent results in supersaturation followed by the crystallization of the API. In this work, a model is developed to estimate the supersaturation profile of solute in a droplet falling in the SC CO2 environment. The droplet consists of paracetamol as a solute and ethanol as a solvent. It moves down in the antisolvent (supercritical CO2) environment. Interestingly, the present model predicts a rise in supersaturation followed by a fall for a while and then a sharp increase. The competing phenomena of nucleation and growth mechanisms are used to justify this variation in the supersaturation.