Organic Melt Crystallization as a Method for Synthesis of Supramolecular Complexes

The most simple method for solventless synthesis of supramolecular complex of CMCR·2BPY·BZP, [CMCR = C-methylcalix[4]resorcinarene, BPY = 4,4'-bipyridine, BZP = benzophenone], is proposed. Although CMCR by itself is high melting point compound (above 300°C), CMCR was found to be dissolved in melt mixture of BPY and BZPeven below 120°C. In the mixture of the three components, the reaction occurs to form CMCR·2BPY·BZP supramolecular complex.

Fabrication and Properties of Aluminabased Reticulated Porous Ceramics

The primary impregnation slurry was prepared using active alumina(56.25 mass%),kaolin(15 mass%),zirconia(3.75 mass%),deionized water(25 mass%),and extra adding FS(0.2 mass%)and CMC(0.4 mass%).The effects of the active alumina particle size(d50=5.043,2.934,and 1.629μm)on the rheology and the thixotropy of the slurry were researched.It was found that the bimodal activeα-Al2O3(AMA-10)with d50=1.629μm was optimum.The secondary impregnation slurry was prepared using AMA-10,kaolin and zirconia as the main raw materials.Then the alumina-based reticulated porous ceramics were fabricated by the organic foam impregnation method combined with a secondary vacuum impregnation process.The influence of the AMA-10 content on the properties of the ceramics was studied.The residual stress of the specimens was analyzed by finite element analysis.The results show that the smaller alumina particle size and multimodal distribution are beneficial to the thixotropy of the primary impregnation slurry.The secondary vacuum impregnation technique can significantly improve the mechanical properties,the thermal shock resistance and the residual strength of the alumina-based reticulated porous ceramics.With the decrease of alumina content in the secondary impregnation slurry,the residual stress of the external layer of ceramic reinforcement gradually changes from tensile stress to compressive stress,which effectively inhibits the expansion of the surface crack,and remarkably improves the crushing strength retention ratio of alumina reticulated porous ceramics.

Critical process parameter identification of manufacturing processes of Astragali Radix extract with a weighted determination coeffcient method

Objective:Critical process parameters(CPPs)identification is an important step of the implementation of quality by design(Qb D)concept.There are many CPP identification methods,such as risk analysis method,sensitivity analysis method,multiple linear regression method,standard partial regression coefficient(SPRC)method,and so on.The SPRC method can consider multiple process critical quality attributes(CQAs)simultaneously,but the determination of CPP number is subjective.Therefore,new CPP identification method is still required.Methods:The manufacturing process of Astragali Radix extract,which contained water reflux extraction,concentration,and ethanol precipitation,was used as an example.First,the multiple process CQAs were determined to be the yield of pigment,dry matter,sugars,and active ingredients.Second,the potential CPPs were determined by a knowledge organization method.Plackett-Burman designed experiments were then performed.A weighted determination coefficient(R2 w)method was presented to identify CPPs.In this method,the importance of different CQAs was considered.Process parameters were removed one-by-one according to their importance index.The decrease in R2 wwas used to characterize the importance of the removed parameter.If the decrease of R2 wwas less than a preset threshold,the removed parameter was not a CPP.Results:During the manufacturing process of Astragali Radix extract,the potential CPPs determined by the knowledge organization method were water consumption,reflux extraction time,extraction frequency,ethanol content,ethanol consumption,and concentration endpoint.Reflux extraction time,the first ethanol consumption,the second ethanol consumption,and the second ethanol precipitation refrigeration temperature were found to be CPPs using the weighted determination coefficient method with the threshold of 10%.Conclusion:Using the weighted determination coefficient method,CPPs can be determined with all the CQAs considered based on their importance.The determination of CPP number is more objective compared with the SPRC method.

An effective method for the hydrodehalogenation of organic halides

THE reduction of organic halides to the corresponding hydrocarbons plays an important role inorganic synthesis and environmental decontamination.It is one of the earliest reactions de-scribed in the organic chemical literature.A number of successful approaches have been report-ed hitherto,but the hydrodehalogenation of chloroarenes and organic fluorides is still a

Ultrathin Ni/V-layered double hydroxide nanosheets for efficient visible-light-driven photocatalytic nitrogen reduction to ammonia

Ammonia is important for industrial development and human life.The traditional Haber Bosch method converts nitrogen into ammonia gas at high temperatures and pressures,causing serious pollution and greenhouse gas emissions.These problems prompt the nitrogen fixation method to proceed in a sustainable way.Ultrathin Ni/V-layered double hydroxides(Ni/V-LDHs)nanosheets with different proportions were prepared successfully for photocatalystic reduction of nitrogen to ammonia,through aqueous miscible organic solvent method(AMO)to achieve the higher surface area and rich oxygen vacancies,containing more carriers and active sites to enhance nitrogen reduction.And the optimal catalyst of Ni/V-LDHs 11 AMO possesses the highest photocatalytic efficiency(176μmol·g^(-1)·h^(-1)),indicating its potential application prospects in catalyst fields.Consequently,this work achieves an environmentally friendly,low-cost and efficient conversion method for nitrogen reduction to ammonia through solar energy.