Combining electrospinning with hot drawing process to fabricate high performance poly (L-lactic acid) nanofiber yarns for advanced nanostructured bio-textiles

2021 ◽  
Author(s):  
Shaohua Wu ◽  
Jiao Liu ◽  
Jiangyu Cai ◽  
Jinzhong Zhao ◽  
Shaojuan Chen ◽  
...  
Keyword(s):  
Lactic Acid ◽  
High Performance ◽  
Drawing Process ◽  
Hot Drawing

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.

scholarly journals Effects of carbon concentration, oxygen, and controlled pH on the engineering strain Lactiplantibacillus casei E1 in the production of bioethanol from sugarcane molasses

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Song Wang ◽  
Ran Tian ◽  
Buwei Liu ◽  
Hongcai Wang ◽  
Jun Liu ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
High Performance ◽  
Ethanol Yield ◽  
Starter Culture ◽  
Market Price ◽  
Sugarcane Molasses ◽  
Engineering Strain ◽  
Carbohydrate Utilization ◽  
Cane Molasses

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.

In Vitro Removal of Ochratoxin A by Wine Lactic Acid Bacteria

2007 ◽  
Vol 70 (9) ◽  
pp. 2155-2160 ◽  
Author(s):  
VINCENZO DEL PRETE ◽  
HECTOR RODRIGUEZ ◽  
ALFONSO V. CARRASCOSA ◽  
BLANCA de las RIVAS ◽  
EMILIA GARCIA-MORUNO ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Ochratoxin A ◽  
High Performance ◽  
Culture Medium ◽  
Degradation Products ◽  
Cell Binding ◽  
A Cell ◽  
In Vitro Interaction

A study was carried out to determine the in vitro interaction between ochratoxin A (OTA) and wine lactic acid bacteria (LAB). Fifteen strains belonging to five relevant oenological LAB species were grown in liquid synthetic culture medium containing OTA. The portion of OTA removed during the bacterial growth was 8 to 28%. The OTA removed from the supernatants was partially recovered (31 to 57%) from the bacterial pellet. Cell-free extracts of three representative strains were produced by disrupting cells in a French pressure cell. The ability of crude cell-free extracts to degrade OTA was studied. OTA was not degraded by cell-free extracts of wine LAB strains, and no degradation products of OTA were detected in the high-performance liquid chromatograms of the methanol extract of the bacterial pellet. On the basis of these results, we conclude that OTA removal by wine LAB is a cell-binding phenomenon. The chemistry and the molecular basis of OTA binding to wine LAB remains unknown.

scholarly journals Semi-metallic, strong and stretchable wet-spun conjugated polymer microfibers

2015 ◽  
Vol 3 (11) ◽  
pp. 2528-2538 ◽  
Author(s):  
Jian Zhou ◽  
Er Qiang Li ◽  
Ruipeng Li ◽  
Xuezhu Xu ◽  
Isaac Aguilar Ventura ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Conjugated Polymer ◽  
High Performance ◽  
Wet Spinning ◽  
Hot Drawing ◽  
Polymer Microfibers

High-performance conjugated polymer microfibers were fabricated via wet-spinning followed by hot-drawing. With a combination of solvent doping and de-doping, we achieved a record electrical conductivity of 2804 S cm−1.

scholarly journals Stationary phase type and temperature effect on HPLC separation of lactic acid enantiomers

2021 ◽  
Vol 14 (1) ◽  
pp. 60-65
Author(s):  
Laura Jánovová ◽  
Katarína Hroboňová
Keyword(s):  
Lactic Acid ◽  
High Performance ◽  
Stationary Phases ◽  
Chiral Stationary Phases ◽  
Reversed Phase ◽  
Optical Isomers ◽  
Column Temperature ◽  
Retention Factors ◽  
Chromatographic Parameters ◽  
Macrocyclic Antibiotics

Abstract Lactic acid is a biologically important organic acid existing in two enantiomeric forms which are differently metabolized in the human body. In this paper, direct chiral separation of lactic acid by high performance liquid chromatography is presented. Five chiral stationary phases based on macrocyclic antibiotics were used for enantioseparation and chromatographic parameters, such as retention factors, resolution and selectivity factors, were determined under different column temperatures ranging from 5 to 45 °C. Optical isomers of lactic acid were efficiently separated using chiral stationary phases based on teicoplanin (R S = 1.9 ) and ristocetin (R S = 1.7 ) in reversed-phase separation mode at the column temperature of 25 °C.

scholarly journals Improvement of Mechanical Properties for Poly (L-lactic acid) Film through Drawing Process Optimization

2004 ◽  
Vol 60 (7) ◽  
pp. 230-234 ◽  
Author(s):  
Jun Takagi ◽  
Tomoyuki Nemoto ◽  
Tatsuhiro Takahashi ◽  
Takashi Taniguchi ◽  
Kiyohito Koyama
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Process Optimization ◽  
Drawing Process

scholarly journals The differences in energy system demands of competitive male tennis play between fast and slow courts

2019 ◽  
Vol 27 (79) ◽  
pp. 11-14
Author(s):  
Аnna Skorodumova ◽  
Igor Baranov
Keyword(s):  
Lactic Acid ◽  
High Performance ◽  
Energy Use ◽  
Energy System ◽  
Analysis Data ◽  
Significant Difference ◽  
Playing Time ◽  
Acid Pathway ◽  
Motor Density ◽  
Energy Pathways

This study investigated the energy system demand differences between matches played on fast courts and on slow courts of high-performance male players. Matches of Grand Slam matches played by Russian players were analysed. External indicators as such in-point playing time as a proportion of total match time were used to conduct the analysis. Data analysis found significant differences in all measured external indicators such as average match playing time, number of points and in-point time. Results also found a significant difference between match motor density (the percentage of total match time that made up effective playing time) for the two surface types, with the slow surface (clay) match motor density being significantly higher than that of the fast surface (grass and hard court), 14.5% and 12.9%, respectively. Subsequent analysis of point length reveals clay courts that slow courts had a significantly higher percentage of points that lasted more than 10 seconds whilst fast courts has a higher percentage of points under 10 seconds in length. It can be concluded that due to the length of the points, tennis primarily employs the ATP-PCr energy system for energy use, dipping into the anaerobic lactic acid energy pathways more on clay court matches. Whilst the aerobic pathways are not employed heavily in-point, they are still essential, possibly even more on clay court due to greater taxation on the anaerobic lactic acid pathway, as they provide the basis for ATP re-synthesis between points. This signals toward endurance as a major component of fitness in tennis.

scholarly journals Structure and performance analysis of flatter ribbon-like electrospun poly(L-lactic acid)/graphene oxide nanofiber webs

2020 ◽  
Vol 15 ◽  
pp. 155892502095292
Author(s):  
Hui Ma ◽  
Huanxia Zhang ◽  
Dongsheng Wang ◽  
Xiangyu Zeng ◽  
Jie Yi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Lactic Acid ◽  
Tensile Stress ◽  
High Performance ◽  
Stress Test ◽  
Hydrolytic Degradation ◽  
Average Diameter ◽  
Electrospinning Technique ◽  
Sem Image ◽  
And Performance

Polylactic acid matrix composites are widely used in packagings and biomaterials. The specific surface area, flexibility and degradation efficiency of the material are the key factors to determine its application in these fields. In this study, a series of poly(L-lactic acid) (PLLA)/graphene oxide (GO) composite nanofiber webs were prepared using electrospinning technique. The scanning electron microscope (SEM) image of PLLA/GO nanofibers showed a rougher surface and a smaller average diameter compared with that of pure PLLA nanofibers, and the nanofibers with 6 wt% GO in PLLA matrix looked like flatter ribbon. Accordingly, the tensile stress test of the electrospun webs with different GO contents showed high performance, 400% increment in the tensile stress at presence of 6 wt% GO. The hydrolytic degradation behavior of composite the nanofiber webs exhibited that the presence of GOs greatly improved the degradation rate, after 9 days, the degradation ratio of PLLA/GO can reach 16.83%. of the PLLA matrix, resulting from the better hydrophilic property and absorbability. Using GO to improve the preparation of new biocompatible materials from PLLA can provide a reference for problems in the field of packaging materials.

Mechanical properties of wood flour/poly (lactic acid) composites coupled with waterborne silane-polyacrylate copolymer emulsion

Holzforschung ◽  
2016 ◽  
Vol 70 (5) ◽  
pp. 439-447 ◽  
Author(s):  
Ru Liu ◽  
Shupin Luo ◽  
Jinzhen Cao ◽  
Yu Chen
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
High Performance ◽  
Coupling Effect ◽  
Wood Flour ◽  
Flexural Modulus ◽  
Coupling Agents ◽  
Poly Lactic Acid ◽  
Effective Coupling ◽  
Methacryloxypropyl Trimethoxysilane

Abstract Wood flour/polylactic acid (WF/PLA) composites were produced with a WF content of 50% based on three types of waterborne polyacrylate (PA) emulsions including a PA homopolymer emulsion and two types of silane-PA copolymer emulsions as coupling agents. Two silanes were in focus, namely, γ-methacryloxypropyl- trimethoxysilane (silane-1) and vinyltrimethoxysilane (silane-2). The emulsions and the modified WFs were characterized, and the effects were investigated in terms of emulsion type and their loading levels on the mechanical properties of WF/PLA composites. (1) Both types of silanes could be successfully copolymerized with PA to form stable emulsions. (2) With increasing PA loading, the mechanical properties (except for flexural modulus) of the composites increased at first before reaching the maximum values at 4% PA loading and then the properties worsened. However, these values were larger than those of pure composites, especially in cases when PA-silane emulsions were applied. (3) PA modified with silane-1 showed the best coupling effect among all the three PA emulsions. The results can be interpreted that PA emulsions are effective coupling agents for the preparation of high-performance WPCs.

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