The solubility and nucleation of borax decahydrate in the presence of Cl– and SO42– ions have been studied by two different methods: polythermal crystallization and isothermal crystallization. The results revealed that both anions had a salt-in effect on the solubility. A noticeable widening of the metastable zone was observed after the addition of the two anion impurities. For the isothermal crystallization, two different nucleation mechanisms were obtained. When the supersaturation ratio S > 1.3, the nucleation appears to be homogeneous, whereas at the supersaturation ratio S < 1.25, heterogeneous nucleation predominates. From the prolonged induction period in the presence of the two anions, we conclude that the nucleation of borax decahydrate was suppressed after the addition of impurities. The values of the interfacial energy γ calculated by isothermal method are lower than those obtained by polythermal method due to the underestimated values of ln S.

Effect of Impurities on the Solubility, Metastable Zone Width, and Nucleation Kinetics of Borax

For the purpose of enhancing the solubility and humidity stability of pymetrozine (PMZ), a highly active but nonbiocidal pesticide, new multicomponent crystals were developed based on the connotati...

New Salts and Cocrystals of Pymetrozine with Improvements on Solubility and Humidity Stability: Experimental and Theoretical Study

Image analysis enables the estimation of critical process properties such as crystal size, morphology, and crystallization kinetics. Despite the rich image information, the lack of a robust image analysis technique has been an obstacle to promote its applications. In this work, an automated image analysis technique that combines the state-of-the-art oriented object detection model, S2A-Net, was developed for in situ estimation of the two-dimensional crystal size distribution (CSD) and the crystal counts. The model was trained to detect and classify both crystals and clusters to enable quantification of the extent of agglomeration and exclude unreliable detections. The effectiveness and robustness of extracting size and aspect ratio at various image complexities were verified by comparing with the focused beam reflective measurement (FBRM) and manually analyzed images in the experimental studies for taurine batch cooling crystallization with different seed loadings. An on-line calibration strategy for solute concentration measurement with Raman spectroscopy was introduced to eliminate the dedicated calibration experiments. The secondary nucleation and growth rate kinetics were evaluated from the on-line measurements and validated by numerical simulation. The proposed method provides a novel PAT strategy that enables accurate two-dimensional size measurement and shape characterization for online monitoring and control of a solution crystallization process.

Deep learning-based oriented object detection for in situ image monitoring and analysis: A process analytical technology (PAT) application for taurine crystallization

Measurement and correlation of the solubility of kojic acid in pure and binary solvents

5-Sulfosalicylic acid as an acid hydrotrope for the rapid and green fractionation of woody biomass

Effect of Sodium Sulfate on Nucleation Behavior and the Crystal Morphology of Taurine

Nicosulfuron (NS) is a widely used sulfonylurea herbicide because of its high selectivity, broad spectrum of herbicide activity, and excellent performance. In this work, nicosulfuron methanol solvate (NS-MeOH) and [[3-[(Dimethylamino)carbonyl]-2-pyridinyl]sulfonyl]carbamic acid methyl ester (PCM) as a product of methanolysis of NS were obtained. Both of their structures were determined by a single crystal X-ray diffraction. A broad range of analytical techniques was applied to characterize the NS-MeOH, such as Powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and hot stage microscopy (HSM). Combined with the analysis of the Independent gradient model (IGM), Atom-in-molecules (AIM), and Hirshfeld surface (HS), direct insights into the role of solvent played in the formation of NS-MeOH and the mechanism of solid-to-solid phase transformation of NS-MeOH could be obtained. In addition, the aqueous solubility of NS was improved through the formation of NS-MeOH. A systematic investigation of herbicidal activity of NS and PCM was carried out. It was found that NS and NS-MeOH had similar herbicidal activities at the experimental concentrations while PCM exhibited significantly lower activity. It was suggested that methanolysis of the sulfonylurea bridge in the NS molecule exerted a great influence on the herbicidal activity.

https://www.mdpi.com/2073-4352/10/3/157/pdf

Toward an Understanding of the Formation and Desolvation of Methanol Solvate, and Structure of Methanolysis Product: A Case Study of Nicosulfuron

The solubility data of sorbic acid in binary systems of (ethanol + water), (1-propanol + water) and (2-propanol + water) were measured from 283.15 to 323.15 K using the static equilibrium method under atmospheric pressure. It was found that the solubility of sorbic acid in the three binary solvent systems increased with increasing temperature as well as increasing initial mole fraction of organic solvent in these systems. The van’t Hoff–Jouyban–Acree model, the modified Apelblat–Jouyban–Acree model and the CNIBS/R-K model were proposed for correlating the experimental solubility values in various solution systems. Furthermore, the dissolution thermodynamic properties of Gibbs energy change (ΔsolGo), molar enthalpy change (ΔsolHo) and molar entropy change (ΔsolSo) were calculated from the experimental solubility data, using the van’t Hoff equation. The positive values of ΔsolGo, ΔsolHo and ΔsolSo indicate that these dissolution processes of sorbic acid in the solvents studied were all endothermic and entropically favorable. In addition, the change of dissolution enthalpy was the main contributor to the positive value of the molar Gibbs energy of the dissolution process. The experimental solubility and the models used in this work would be conducive to purifying sorbic acid from its crude mixtures.

Solubility Measurements and Thermodynamic Properties of Sorbic Acid in Binary Solvent Mixtures of (Ethanol, 1-Propanol or 2-Propanol + Water) from 283.15 to 323.15 K

In view of the weak aromatic characteristic resulting from the weak π-bonding ability (different from the analogous graphene), employing two-dimensional (2D) silicene and germanene monolayers could be one of the most promising ways to realize a new type of highly efficient and nonprecious catalyst for the hydrogen evolution reaction (HER). However, the HER activity of pristine silicene and germanene has to be improved, although both of them can exhibit a good change trend. Particularly, the hydrogen phenomenon can occur under moderate or high H* coverage on 2D silicene and germanene. To overcome these bottlenecks, in this study we identify the most effective strategy through doping P with a lone pair to significantly improve the HER catalytic activity under a high H* coverage, by screening a series of IIIA (i.e., B, Al, Ga, In and Tl) and VA (i.e., N, P, As, Sb and Bi) heteroatoms with different electronegativity under detailed DFT calculations. It is revealed that the doped P atoms and almost all the Si/Ge atoms can uniformly serve as highly active sites. Especially, in view of the existence of the lone pair, doping P effectively prevents hydrogenation (even under full H* coverage) by increasing the structural rigidity. Moreover, the P-doping concentration also plays a crucial role in obtaining high HER activity. The relevant mechanisms have been analyzed in detail. Clearly, all these fascinating findings are beneficial for realizing new HER electrocatalysts based on the excellent silicene or germanene nanomaterials, and even other Si/Ge-related materials in the near future.

Doping P atom with a lone pair: an effective strategy to realize high HER catalytic activity and avoid deactivation under wide H* coverage on 2D silicene and germanene by increasing the structural rigidity.

Huaxiang Zhu

Papers

Effect of Sodium Sulfate on Nucleation Behavior and the Crystal Morphology of Taurine

Toward an Understanding of the Formation and Desolvation of Methanol Solvate, and Structure of Methanolysis Product: A Case Study of Nicosulfuron

Solubility Measurements and Thermodynamic Properties of Sorbic Acid in Binary Solvent Mixtures of (Ethanol, 1-Propanol or 2-Propanol + Water) from 283.15 to 323.15 K

Doping P atom with a lone pair: an effective strategy to realize high HER catalytic activity and avoid deactivation under wide H* coverage on 2D silicene and germanene by increasing the structural rigidity.

2D RhTe Monolayer: A highly efficient electrocatalyst for oxygen reduction reaction.