Transmission analysis in ultrafiltration of ternary protein mixture through a hydrophilic membrane

One of the main reasons for the underutilization of ultrafiltration has been the lack of experimental data on transmission of proteins for complex systems and its corresponding theoretical analysis. Of course, the presence of fouling coupled with concentration polarization have had their share in making ultrafiltration operation a difficult one to understand. In the present study, the systematic ultrafiltration of 3-protein mixture, namely lysozyme, myoglobin and ovalbumin, has been carried out using a hydrophilic 30,000 molecular weight cut off membrane. The experimental data of individual protein transmission in ternary mixture showed a very low transmission (as low as 3% for ovalbumin) to a very high transmission (as high as 90% for lysozyme) of proteins for different operating conditions. This behaviour of each protein in the mixture was analyzed using combined concentration polarization and irreversible thermodynamics model. The parameters of the modeled values gave a very good fit with experimental data and the resulting analysis indicated some interesting findings, which are discussed in this paper. The comparison of parameters obtained for single protein solution and the ternary protein solution showed some unusual results that point to the presence of the protein–protein and protein–membrane interactions.     

K3BiSe3, Rb3BiSe3 und Cs3BiSe3 – Substitutionsvarianten des Th3P4-Typs

K₃BiSe₃, Rb₃BiSe₃, and Cs₃BiSe₃ – Derivatives of the Th₃P₄ Structure Type The compounds K₃BiSe₃, Rb₃BiSe₃, and Cs₃BiSe₃ were synthesized by heating mixtures of Bi₂O₃ and the respective alkalicarbonate in a stream of hydrogen saturated by selenium at 850°C. Thin crystals of the compounds appear red in transmitted light. They crystallize isostructural with Na₃AsS₃, space group P2₁3, lattice constants a = 9.771(5) Å, a = 10.161(3) Å, and a = 10.587(5) Å for K₃BiSe₃, Rb₃BiSe₃, and Cs₃BiSe₃, respectively. The Na₃AsS₃ structure type is a derivative of the Th₃P₄ structure type.     

RbNO_3-C_2H_5OH-H_2O三元体系的液-固相平衡及其性质

测定了RbNO3-C2H5OH-H2O体系在25℃和50℃的等温平衡溶解度及饱和液的性质(密度和折光率).绘制了相图,计算了盐析率,评价了盐析效果.用经验公式分别对溶解度、密度和折光率进行了关联,效果良好.体系没有产生分层现象,得到的平衡固相皆为无水铷盐,没有新化合物或水合物生成.     

CeCl3-CdCl2-H2O和CeCl3-CdCl2-HCl-H2O的相平衡

测定了三元系CeCl₃-CdCl₂-H₂O (25 ℃)和四元系CeCl₃-CdCl₂-HCl(～8.4％)-H₂O(25 ℃) 的相平衡溶度数据,绘制了相应的溶度图.该三元系是由5个固相区CdCl₂&;#8226;2.5H₂O(原始盐)、CdCl₂&;#8226;H₂O(原始盐)、6CdCl₂&;#8226;CeCl₃&;#8226;14H₂O、4CdCl₂&;#8226;CeCl₃&;#8226;12H₂O、CeCl₃&;#8226;7H₂O(原始盐)组成的复杂体系.该四元系是由5个固相区CdCl₂&;#8226;H₂O(原始盐)、9CdCl₂&;#8226;CeCl₃&;#8226;19H₂O、6CdCl₂&;#8226;CeCl₃&;#8226;14H₂O、4CdCl₂&;#8226;CeCl₃&;#8226;12H₂O、CeCl₃&;#8226;7H₂O(原始盐)组成的复杂体系.其中6CdCl₂&;#8226;CeCl₃&;#8226;14H₂O在该三元系是介稳化合物.9CdCl₂&;#8226;CeCl₃&;#8226;19H₂O 、6CdCl₂&;#8226;CeCl₃&;#8226;14H₂O和4CdCl₂&;#8226;CeCl₃&;#8226;12H₂O用X射线粉末衍射及TG-DTG和DSC等方法进行了研究,并对X射线粉末衍射进行了指标化.     

Temperature Effect on Liquid-Liquid Phase Equilibria of Aqueous Solutions of Fluorobenzene in Ethanol at the Pressure 101.2 kPa

Solubilities and liquid-liquid equilibrium (LLE) data for (water + ethanol + fluorobenzene) solutions are determined at T = (288.15, 298.15, 308.15) K and atmospheric pressure. The titration method is used to construct the binodal curves. All measured solubilities and liquid-liquid equilibrium data are reproduced quantitatively by empirical equations and the NRTL activity coefficient model. The correlated data are consistent to better than 0.3% in phase composition. The studied temperatures have a small effect on the phase equilibrium properties of the investigated systems. The influence of water concentration on the distribution coefficient of ethanol in the coexistent liquid phases and on the fluorobenzene selectivity is important. Practically, fluorobenzene may well be used to produce absolute alcohol.     

Thin Films Made Fast and Modified Fast

Hyperfine Interactions - Thin films are playing a more and more important role for technological applications and there are many aspects of materials surface processing and thin film production,...     

Large‐scale production of well‐dispersed submicro ZrB2 and ZrC powders

ZrB₂ and ZrC powders were synthesized via metallothermic reduction route using ZrO₂, B/C, and Mg as raw materials. Low packing density of the green mixture and high heating temperature of the furnace are crucial for the formation of well‐dispersed submicro powders. Optimum reaction time helped achieve good crystallization and high purity. The as‐prepared samples were characterized by XRD, FESEM, TEM, and particle size analyzer. Results showed that well‐dispersed ZrB₂ powders with mean particle size of 0.534 μm and ZrC powders with mean particle size of 0.376 μm can be obtained. Oxygen content can be controlled lower than 1.0 wt%. The bench‐scale output is about 10 kg/d.     

Bifunctional o-CoSe2/c-CoSe2/MoSe2 heterostructures for enhanced electrocatalytic and photoelectrochemical hydrogen evolution reaction

The bottleneck of alkaline hydrogen evolution reaction lies in the kinetically sluggish brought from multistep reaction processes involving water adsorption and dissociation, as well as hydrogen adsorption. In this work, we successfully synthesized o-CoSe₂/c-CoSe₂ heterostructures anchored on MoSe₂ nanosheets to powerfully promote reaction processes. As an electrocatalyst, it exhibits a low overpotential of 112 mV at 10 mA/cm² and a Tafel slope of 96.9 mV/dec for an alkaline hydrogen evolution reaction. Moreover, the as-prepared catalyst can behave as both cathode and anode for overall water splitting, which only requires 1.61 V cell voltage at 10 mA/cm². Significantly, the cell voltage can be further reduced to 1.53 V at 10 mA/cm² for water electrolysis under the simulated solar irradiation owing to such a semiconductor-based heterostructure that facilitates the separation of photogenerated charges. Here, the improving overall performance of this ternary electrocatalyst is attributed to the multifunctionality and synergistic interaction of different components in this heterogeneous material. The work provides a novel strategy to design active catalysts simultaneously using electric energy and solar energy for effective water splitting.     

Enhanced ternary memory performances with high-temperature tolerance in AIE@PBI composites by tuning the azobenzol substituents on tetraphenylethylene

The design of functional composites with desired film crystallinity and definite switching mechanism is the key to achieve high performance multilevel memorizers. Three aggregation-induced emission (AIE) molecules containing different azobenzol (Azo) groups on tetraphenylethylene (TPE) were synthesized and embedded into polybenzimidazole (PBI) to prepare AIE@PBI composites, which were further fabricated as FTO/TPE-Azo-n@PBI/Ag (n = 01, 02, 04) devices with well-defined crystalline characteristics. These devices can demonstrate clear ternary memory performances, among which TPE-Azo-04@PBI-based one exhibited the best performance with the current ratio of 1:10^4.2:10^6.7 for “OFF”, “ON1”, and “ON2” states. The ternary memory mechanism can be designed as the combination of aggregation-induced current/conductance (AIC) and packing conformational change-induced charge transfer in TPE-Azo-n, which were verified by UV–Vis, in-situ XRD, and single-crystal structural determinations and theoretical calculations. The trend of ternary memory performance improved by increasing Azo groups on TPE can be attributed to the larger steric hindrance due to the more Azo groups, which can inhibit their aggregations and packing conformational change in PBI-confined space. Specially, this kind of devices can present high-temperature tolerance of 350 ^°C. The verified mechanism in this work might provide a practicable model for the design of new high-density memorizers with good environmental tolerance. The current ratio of OFF/ON1/ON2 increases with the Azo.