scholarly journals Mixed Manganese Dioxide on Magnetite Core MnO2@Fe3O4 as a Filler in a High-Performance Magnetic Alginate Membrane

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7667
Author(s):  
Paweł Grzybek ◽  
Roman Turczyn ◽  
Gabriela Dudek
Keyword(s):  
Manganese Dioxide ◽  
Separation Factor ◽  
High Performance ◽  
Separation Efficiency ◽  
Filler Content ◽  
Filler Loading ◽  
Ethanol Dehydration ◽  
Magnetite Nanoparticle ◽  
Nanoparticle Surface ◽  
Strong Relation

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.

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 ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Lactic Acid ◽  
Polymer Matrix ◽  
Separation Factor ◽  
Membrane Structure ◽  
High Performance ◽  
Separation Efficiency ◽  
Pharmaceutical Chemical ◽  
Permeate Flux ◽  
Membrane Components

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.

High Performance Poly (Vinyl Alcohol)-Zeolite LTA Composite Membranes for Ethanol Dehydration Pervaporation

2011 ◽  
Vol 287-290 ◽  
pp. 2053-2056
Author(s):  
Zhen Huang ◽  
Wei Juan Jiang ◽  
Xiao Han Shi ◽  
Li Jun Teng
Keyword(s):  
Separation Factor ◽  
Vinyl Alcohol ◽  
High Performance ◽  
Composite Membranes ◽  
Ethanol Solution ◽  
Poly Vinyl Alcohol ◽  
Processing Temperature ◽  
Ethanol Dehydration ◽  
Zeolite Lta ◽  
Separation Performances

Three-layered zeolite LTA-filled poly (vinyl alcohol) (PVA) composite membranes have been fabricated for water removal from highly concentrated ethanol solution by means of pervaporation. Higher separation factor and higher fluxes are both achieved after adding zeolite 3A, 4A and 5A. Through evaluating separation factor and permeation flux, separation performances of the composite membranes are elucidated in terms of the zeolite pore size and processing temperature.

High Performance Thin Layer Chromatography (HPTLC) for the Investigation of Medicinal Plants

2020 ◽  
Vol 16 ◽  
Author(s):  
Alper Gökbulut
Keyword(s):  
Medicinal Plants ◽  
High Performance ◽  
Separation Efficiency ◽  
Rapid Development ◽  
Herbal Remedies ◽  
Qualitative And Quantitative ◽  
Powerful Analytical Tool ◽  
Quantitative Examination ◽  
Data Acquisition And Processing ◽  
Layer Chromatography

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.

scholarly journals Boron nitride nanoplatelets as two-dimensional thermal fillers in epoxy composites: new scenarios at very low filler loadings

2020 ◽  
Vol 40 (10) ◽  
pp. 859-867
Author(s):  
Yao Shi ◽  
Genlian Lin ◽  
Xi-Fei Ma ◽  
Xiao Huang ◽  
Jing Zhao ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Boron Nitride ◽  
Filler Content ◽  
Hexagonal Boron Nitride ◽  
Filler Loading ◽  
Epoxy Composites ◽  
General Phenomenon ◽  
Sudden Drop ◽  
Reduced Graphene ◽  
Thermal Conducting

AbstractHexagonal boron nitride (h-BN) nanoplatelets (0.6 μm in diameter and 100 nm in thickness) are introduced into epoxy resin to improve the polymer’s thermal conducting ability. As expected, the thermal conductivities (TCs) of the composites, especially the in-plane TCs, are significantly increased. The in-plane TC of the epoxy composites can reach 1.67 W/mK at only 0.53 wt% loading, indicating h-BN nanopletelets are very effective thermal fillers. However, after carefully studied the correlation of the TC improvement and filler content, a sudden drop of the TC around 0.53 wt% filler loading is observed. Such an unexpected decrease in TC has never been reported and is also found to be consistent with the Tg changes versus filler content. Similar trend is also observed in other 2-D nanofillers, such as graphene oxide, reduced graphene oxide, which may indicate it is a general phenomenon for 2-D nanofillers. SEM results suggest that such sudden drop in TC might be coming from the enrichment of these 2-D nanofillers in localized areas due to their tendency to form more ordered phase above certain concentrations.

scholarly journals The Impact of Organizational Culture and Performance Work System on Employees’ Performance

2018 ◽  
Vol 11 (6) ◽  
pp. 199 ◽  
Author(s):  
Amirreza Salehipour ◽  
Abdollah Ah mand
Keyword(s):  
Organizational Culture ◽  
High Performance ◽  
Ministry Of Education ◽  
Work System ◽  
Strong Relation ◽  
High Performance Work System ◽  
Research Questions ◽  
And Performance ◽  
The Impact ◽  
The Given

Necessity of improving employees’ performance in ministry of education in Iran was the reason of conducting this research. Authors are focused on the impact of High Performance Work System (HPWS) and the culture of organization on employees’ performance in Iran ministry of education. By conducting specified study based on distributed survey questionnaire to 162 members of ministry of education in Iran, this study aims to provide answer to the given research questions of study. The outcome of hypotheses testing illustrate HPWS significantly effects ministry members’ performance and shows strong relation between variables. Likewise, organizational culture demonstrates significant affirmative impact on Iran ministry of education members and employees’ performance. Findings of current research indicate that the ministry of education in Iran requires immediate action toward improving performance of members to obtain desired outcome. Accordingly, to the result of present study, current research attempts to provide practical concepts and illustrate limitations, suggestions for improvement of ministry and future study in this field.

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