scholarly journals Enhancing Pervaporation Membrane Selectivity by Incorporating Star Macromolecules Modified with Ionic Liquid for Intensification of Lactic Acid Dehydration

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1811
Author(s):  
Valeriia Rostovtseva ◽  
Alexandra Pulyalina ◽  
Roman Dubovenko ◽  
Ilya Faykov ◽  
Kseniya Subbotina ◽  
...  

Modification of polymer matrix by hybrid fillers is a promising way to produce membranes with excellent separation efficiency due to variations in membrane structure. High-performance membranes for the pervaporation dehydration were produced by modifying poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) to facilitate lactic acid purification. Ionic liquid (IL), heteroarm star macromolecules (HSM), and their combination (IL:HSM) were employed as additives to the polymer matrix. The composition and structure of hybrid membranes were characterized by X-ray diffraction and FTIR spectroscopy. Scanning electron microscopy was used to investigate the membranes surface and cross-section morphology. It was established that the inclusion of modifiers in the polymer matrix leads to the change of membrane structure. The influence of IL:HSM was also studied via sorption experiments and pervaporation of water‒lactic acid mixtures. Lactic acid is an essential compound in many industries, including food, pharmaceutical, chemical, while the recovering and purifying account for approximately 50% of its production cost. It was found that the membranes selectively remove water from the feed. Quantum mechanical calculations determine the favorable interactions between various membrane components and the liquid mixture. With IL:HSM addition, the separation factor and performance in lactic acid dehydration were improved compared with pure polymer membrane. The best performance was found for (HSM: IL)-PPO/UPM composite membrane, where the permeate flux and the separation factor of about 0.06 kg m−2 h−1 and 749, respectively, were obtained. The research results demonstrated that ionic liquids in combination with star macromolecules for membrane modification could be a promising approach for membrane design.

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7667
Author(s):  
Paweł Grzybek ◽  
Roman Turczyn ◽  
Gabriela Dudek

The process of ethanol dehydration via pervaporation was performed using alginate membranes filled with manganese dioxide and a mixed filler consisting of manganese dioxide on magnetite core MnO2@Fe3O4 particles. The crystallization of manganese dioxide on magnetite nanoparticle surface resulted in a better dispersibility of this mixed filler in polymer matrix, with the preservation of the magnetic properties of magnetite. The prepared membranes were characterized by contact angle, degree of swelling and SEM microscopy measurements and correlated with their effectiveness in the pervaporative dehydration of ethanol. The results show a strong relation between filler properties and separation efficiency. The membranes filled with the mixed filler outperformed the membranes containing only neat oxide, exhibiting both higher flux and separation factor. The performance changed depending on filler content; thus, the presence of optimum filler loading was observed for the studied membranes. The best results were obtained for the alginate membrane filled with 7 wt.% of mixed filler MnO2@Fe3O4 particles. For this membrane, the separation factor and flux equalled to 483 and 1.22 kg·m−2·h−1, respectively.


2020 ◽  
Vol 16 ◽  
Author(s):  
Alper Gökbulut

Background: Chromatographic techniques such as TLC basically and, HPLC, GC, HPTLC equipped with various detectors are most frequently used for the qualitative and quantitative examination of herbals. Method: An overview of the recent literature concerning the usage of HPTLC for the analysis of medicinal plants has been reviewed. Results: During the last decade/s, HPTLC, a modern, sophisticated and automatized TLC technique with better and advanced separation efficiency, detection limit, data acquisition and processing, has been used for the analysis of herbal materials and preparations since the rapid development of technology in chromatography world. HPTLC with various detectors is a powerful analytical tool especially for the phytochemical applications such as herbal drug quantification and fingerprint analysis. Conclusion: In this review, a latest perspective has been established and some of the previous studies were summarized for the usage of HPTLC in the analysis of herbal remedies, dietary supplements and nutraceuticals.


AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Song Wang ◽  
Ran Tian ◽  
Buwei Liu ◽  
Hongcai Wang ◽  
Jun Liu ◽  
...  

AbstractSugarcane molasses are considered a potential source for bioethanol’s commercial production because of its availability and low market price. It contains high concentrations of fermentable sugars that can be directly metabolized by microbial fermentation. Heterofermentative lactic acid bacteria, especially Lactiplantibacillus casei, have a high potential to be a biocatalyst in ethanol production that they are characterized by strong abilities of carbohydrate metabolism, ethanol synthesis, and high alcohol tolerance. This study aimed to evaluate the feasibility of producing ethanol by Lactiplantibacillus casei used the ethanologen engineering strain L. casei E1 as a starter culture and cane molasses as substrate medium. The effects of environmental factors on the metabolism of L. casei E1 were analyzed by high-performance liquid chromatography (HPLC) system, and the gene expression of key enzymes in carbon source metabolism was detected using quantitative real-time PCR (RT–qPCR). Results showed that the strain could grow well, ferment sugar quickly in cane molasses. By fermenting this bacterium anaerobically at 37 °C for 36 h incubation in 5 °BX molasses when the fermenter’s pH was controlled at 6.0, ethanol yield reached 13.77 g/L, and carbohydrate utilization percentage was 78.60%. RT-qPCR results verified the strain preferentially ferment glucose and fructose of molasses to ethanol at the molecular level. In addition, the metabolism of sugars, especially fructose, would be inhibited by elevating acidity. Our findings support the theoretical basis for exploring Lactic acid bacteria as a starter culture for converting sugarcane molasses into ethanol.


2021 ◽  
Vol 412 ◽  
pp. 127034
Author(s):  
Yang Yu ◽  
Zhuoya Ren ◽  
Qianqian Shang ◽  
Jiangang Han ◽  
Lei Li ◽  
...  

2016 ◽  
Vol 4 (36) ◽  
pp. 13822-13829 ◽  
Author(s):  
Xiaowei Li ◽  
Sijian Li ◽  
Zhengxi Zhang ◽  
Jun Huang ◽  
Li Yang ◽  
...  

Hybrid ionogel electrolytes have high thermal and electrochemical stability, good ionic conductivity, and potential to suppress Li dendrite formation. Solid-state lithium metal batteries with hybrid electrolytes reveal high capacity and remarkable rate performance.


2017 ◽  
Vol 737 ◽  
pp. 269-274
Author(s):  
Sirirat Wacharawichanant ◽  
Chaninthon Ounyai ◽  
Ployvaree Rassamee

The effects of four types of organoclay on morphology and mechanical properties of poly(lactic acid) (PLA)/propylene-ethylene copolymer (PEC) blends were investigated. The ratio of PLA and PEC was 80/20 by weight and the organoclay content was 5 phr. The morphology analysis showed that the addition of all oganocaly types could improve the miscibility of PLA and PEC blends due to the decreased of the domain sizes of PEC dispersed phase in the polymer matrix. The tensile properties showed Young’s modulus of the PLA/PEC blends was improved after adding clay treated surface with 25-30 wt% trimethyl stearyl ammonium.


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