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Membranes were fabricated with high-density polyethylene (HDPE) and ethylene vinyl acetate (EVA) blend through thermally induced phase separation and were then used for vacuum membrane distillation (VMD). The membranes were supported by nonwoven polyester fabric with a special cellular structure. Different membrane samples were obtained by adjusting the polymer concentration, HDPE/EVA weight ratio, and coagulation bath temperature. The membranes were characterized by scanning electron microscopy (SEM) analysis, contact angle test, and evaluation of porosity and pore size distribution. A series of VMD tests were conducted using aqueous NaCl solution (0.5 mol·L−1) at a feed temperature of 65 °C and permeate side absolute pressure of 3 kPa. The membranes showed excellent performance in water permeation flux, salt rejection, and long-term stability. The HDPE/EVA co-blending membranes exhibited the largest permeation flux of 23.87 kg·m−2·h−1 and benign salt rejection of ≥ 99.9%.

Chinese goldthread (Coptis chinensis Franch.), a member of the Ranunculales, represents an important early-diverging eudicot lineage with diverse medicinal applications. Here, we present a high-quality chromosome-scale genome assembly and annotation of C. chinensis. Phylogenetic and comparative genomic analyses reveal the phylogenetic placement of this species and identify a single round of ancient whole-genome duplication (WGD) shared by the Ranunculaceae. We characterize genes involved in the biosynthesis of protoberberine-type alkaloids in C. chinensis. In particular, local genomic tandem duplications contribute to member amplification of a Ranunculales clade-specific gene family of the cytochrome P450 (CYP) 719. The functional versatility of a key CYP719 gene that encodes the (S)-canadine synthase enzyme involved in the berberine biosynthesis pathway may play critical roles in the diversification of other berberine-related alkaloids in C. chinensis. Our study provides insights into the genomic landscape of early-diverging eudicots and provides a valuable model genome for genetic and applied studies of Ranunculales., Coptis chinensis represents an early-diverging eudicot lineage with diverse medicinal applications. Here, the authors report its chromosome-scale genome assembly, infer a single ancient whole-genome duplication, and characterize the function of CYP719 in diversification of protoberberine-type alkaloids.

Isotactic polypropylene (iPP)/ethylene vinyl acetate (EVA) co-blending hydrophobic microporous membranes for vacuum membrane distillation (VMD) were prepared via thermally induced phase separation (TIPS), and the membranes were supported by a nonwoven polyester fabric with special cellular structures. These special cellular structures consist of two parts: a thin dense cellular layer and a thick loose cellular layer. These structures markedly decreased the resistance of mass transfer and improved flux performance during VMD. The co-blending membranes used for VMD led to superior long-term stability and excellent durability relative to neat PP membranes. This result can be attributed to the addition of EVA that significantly reduced membrane crystallinity. The thickness of the dense cellular layer and voids of the loose cellular layer showed a minimum and a maximum at a PP/EVA co-blending ratio of 6:1, respectively. Aqueous NaCl solutions (0.5 mol/L) were used in the VMD experiment at a feed temperature of 70 °C and a permeate side absolute pressure of 3 kPa. The flux of the iPP/EVA co-blending membranes was 27.6 kg/(m2 h) within 36 h of continuous operation, whereas that of the iPP membranes was only approximately 16 kg/(m2 h) within 6 h of continuous operation under the same condition.

Capsules prepared by the layer-by-layer (LbL) technique are gaining interest. This work proposed a novel approach to improving the mechanical stability of LbL microcapsules under mild conditions by the self-polymerisation of dopamine among different polymers in aqueous solution. More specifically, common poly(sodium styrenesulfonate)/poly(sodium 4-styrenesulfonate) (PSS/PAH) microcapsules were prepared using layer-by-layer method. The as-prepared microcapsule was then treated with dopamine and compared with PSS/PAH microcapsules fabricated by a similar protocol without dopamine treatment. The morphology, structure, and chemical composition of the microcapsules were characterised, and the underlying mechanism was tentatively discussed. To explore the application potential of the microcapsules, glucosidase was encapsulated for the conversion of maltose to isomaltooligosaccharides.

Pitzer ion-interaction theory is widely used to calculate the solubilities of salt–water systems. In the paper, the solubilities and equiscale lines of water contents of the reciprocal quaternary system (Li+Na+Cl+SO4+H2O) at 298.15 K were calculated using Pitzer theory and Harvie, Moller, Weare solubility modeling approach (HMW model). In this predictive calculation, the quasi-Newton and dichotomy methods were used to solve the system of simultaneous equations of the equilibrium expressions among solid and liquid phases, and to obtain the ionic molalities, Janecke indices of phase diagram and the Janecke indices of the equiscale lines of water contents in the reciprocal quaternary system. Based on the Janecke indices, the dry-salt phase diagram and the equiscale lines of water-phase diagram were plotted. The predictive phase diagram via the theoretical calculation agrees well with the experimental phase diagram except for the phase region of double salt 2 (Li2SO4·Na2SO4, Db2). Distributions of equiscale lines of water-phase diagram on the dry-salt diagram of the reciprocal quaternary system reflect that phase areas of double salts of Db1 and Db2 bear maximal water contents. The predictive phase diagram and equiscale lines of water-phase diagram are often necessary in the technological design of chemical engineering for the utilization of inorganic salts in salt lake brines.

A three-dimensional numerical simulation of a vacuum membrane distillation (VMD) process for aqueous NaCl solution was conducted to understand the vapor and liquid distribution in the hollow fiber membrane module. This understanding is critical for membrane module design as well as heat and mass transfer enhancement. Computational fluid dynamics were used to simulate the VMD process using FLUENT software, and the mixture model and standard k–ϵ model were used to describe the turbulent flow. The vapor and liquid distribution along the entire membrane module were simulated. The membrane thickness, feed temperature, pressure, parameters on the boundary layer, and cross-section in the VMD process were also studied. It was shown that the pressure change and liquid volume fraction change were mainly in membrane silk. The vapor and liquid were found to be distributed inside the membrane silk and shell, respectively. Most of the changes in pressure, temperature, and phase transition occur on the boundary layer in the membrane silk.

Isotactic polypropylene (iPP) hydrophobic flat-sheet membranes were fabricated for use in vacuum membrane distillation (VMD) through a thermally induced phase-separation process with dispersing hydrophobically modified SiO2 nanoparticles in the casting solution to achieve a higher hydrophobicity and to sustain a stable flux in VMD. The contact angle (CA) measurements indicated that the incorporation of nano-SiO2 into a casting solution mixture containing 20 wt % iPP had a 20.9% higher CA relative to that of SiO2-free membranes. The addition of nano-SiO2 also induced morphological changes in the membrane structure, including changes in the pore size distribution, porosity, and suppression of macrovoids. The pore size distribution of the iPP–SiO2 membranes became narrower compared with that of the SiO2-free membranes, and the porosity also improved from 35.45 to 59.75% with SiO2 addition. The average pore size and maximum pore size of the iPP–SiO2 membranes both decreased. The ability of the membranes to concentrate an astragalus aqueous solution (a type of traditional Chinese medicine) with VMD was investigated. The surface hydrophobicity and antifouling performance of the iPP–SiO2 membranes improved with nano-SiO2 addition to the membrane casting solution. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42615.

Numerical simulation is an effective method to get the optimal operating parameters in the chemical engineering process. In this work, the transport mechanism of vacuum membrane distillation (VMD) process was simulated and predicted by mathematical model, which was established based on the convective heat transfer coefficient, and 0.5M aqueous NaCl solution was concentrated with isotactic polypropylene (iPP) hydrophobic microporous membrane prepared via thermally induced phase separation (TIPS) in the VMD process. The as-presented mathematical model simulated the effects of different operating parameters on the VMD performances for aqueous NaCl solution, such as feed temperature, feed flow rate, absolute pressure of membrane permeate side, temperature coefficient, membrane thickness, and porosity. A comparison between experimental data and simulated data was also considered to verify the proposed mathematical model. Additionally, the salt rejection of aqueous NaCl solution production water in VMD was higher than 99.9%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41632.

Anti-solvent crystallization of potassium dihydrogen phosphate (KDP) from aqueous solution was studied by using on-line Raman spectroscopy. The used anti-solvent was acetone and semi-batch crystallization experiments were conducted by adding acetone into an initially pure aqueous KDP solution saturated at 25 °C. The solubility of KDP in acetone–water mixtures was determined at 25 °C. A calibration model of Raman spectra was created using a series of KDP–water–acetone ternary or binary solutions, and the calibration model was used to attain the on-line KDP concentration profile during the crystallization. The evolution of supersaturation during the whole process was then obtained. The reliability of the calibration model was validated by the off-line measured KDP concentrations. The effects of the feeding rate and feeding position of the anti-solvent on precipitation were discussed based on the obtained supersaturation profile.