Thermodynamic analysis of Li-Ni-Co-Mn-H2O system and synthesis of LiNi0.5Co0.2Mn0.3O2 composite oxide via aqueous process

The constructed potential-pH diagrams of Li-Ni(Co,Mn)-H2O system indicate that the LiNiO2,LiCoO2 and LiMnO2 are thermodynamically stable in aqueous solution within the temperature range of 25-200°C and the activity range of 0.01-1.00.A predominant co-region of LiNiO2,LiCoO2 and LiMnO2 oxides(Li-Ni-Co-Mncomposite oxide)is found in the Li-Ni-Co-Mn-H2O potential-pH diagrams,in which the co-precipitation region expands towards lower pH with rising temperature,indicating the enhanced possibility of synthesizing Li-Ni-Co-Mn composite oxide in aqueous solution.The experimental results prove that it is feasible to prepare the LiNi0.5Co0.2Mn0.3O2 cathode materials(NCM523)by an aqueous routine.The as-prepared lithiated precursor and NCM523 both inherit the spherical morphology of the hydroxide precursor and the obtained NCM523 has a hexagonalα-NaFeO2 structure with good crystallinity.It is reasonable to conclude that the aqueous routine for preparing NCM cathode materials is a promising method with the guidance of the reliable potential-pH diagrams to some extent.

Pumpkin seed coat pigments affected aqueous enzymatic extraction processing through interaction with its interfacial protein

In this study,the oil recovery from pumpkin seed with or without the presence of pigment was evaluated during the aqueous enzymatic extraction process(AEEP).Additionally,the interaction of pumpkin seed coat pigment-protochlorophyll(Pchl)with interfacial proteins(globulin-O/W,globulin-W,and albumin-W)during the aqueous extraction process was investigated.When Pchl was removed from pumpkin seeds,the yield of free oil was significantly increased by 50.71%after the first centrifugation.And the total oil recovery increased from 68.59%to 89.91%using enzymatic demulsification.Theβ-sheet percentage of globulin-O/W decreased by 5.6%with the presence of Pchl based on the circular dichroism spectra analysis.The particle size of globulin-W and albumin-W significantly increased in contrast to globulin-O/W.In addition,the increase of surface hydrophobicity and surface sulfhydryl group showed a conformational change of three protein extracts.Fluorescence spectra analyses showed that Pchl quenched the intrinsic fluorescence of globulin-W,albumin-W,and globulin-O/W in a static mode.Thermodynamic analyses indicated that the main force between Pchl and proteins was hydrophobic interactions.The hydrolysis efficiency of Papain was reduced during demulsification in AEEP with the presence of Pchl.Therefore,the removal of pumpkin seed coat pigments facilitated the aqueous extraction of seed oil by getting rid of the interaction of Pchl with its interfacial protein.

Optimization of Ethanol-Ultrasound-Assisted Destabilization of a Cream Recovered from Enzymatic Extraction of Soybean Oil

A novel method using ethanol and ultrasound to extract oil from cream obtained from enzyme-assisted aqueous extraction of soybean oil was developed.To evaluate the relationships between operating variables and free oil yield and to maximize the free oil yield,response surface methodology was introduced in this work.The developed regression model was fitted with R2=0.9591.Optimized variables were:ethanol concentration of73%,ethanol addition volume of 0.55 L/kg,ultrasound power of 427 W,ultrasound time of 47 s,and ultrasound temperature of 53℃.The free oil yield from the cream under the above conditions was 92.6±3.4%.Scanning electron microscopy(SEM)was used to evaluate the effect of ultrasonic treatment on ethanoltreated cream,and the SEM images clearly showed that the ultrasound treatment affected dispersing and fracturing of the microstructure of ethanol-treated cream.