scholarly journals Mass-Production and Characterizations of Polyvinyl Alcohol/Sodium Alginate/Graphene Porous Nanofiber Membranes Using Needleless Dynamic Linear Electrospinning

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1167 ◽  
Author(s):  
Ting-Ting Li ◽  
Mengxue Yan ◽  
Wenting Xu ◽  
Bing-Chiuan Shiu ◽  
Ching-Wen Lou ◽  
...  

The aim of this study was to investigate the feasibility of large-scale preparation of porous polyvinyl alcohol/sodium alginate/graphene (Gr) (Gr-AP) nanofiber membranes using a copper wire needleless dynamic linear electrode electrospinning machine. Furthermore, the effects of Gr concentrations (0, 0.0375, 0.075, 0.25, 0.5, and 0.75 wt.%) on the morphology, electrical, hydrophilicity and thermal properties were evaluated. Results indicate that the dynamic linear electrospun Gr-AP membranes have a high yield of 1.25 g/h and are composed of porous finer nanofibers with a diameter of 141 ± 31 nm. Gr improved the morphology, homogeneity, hydrophobicity and thermal stability of Gr-AP nanofiber membranes. The critical conductive threshold is 0.075 wt.% for Gr, which provides the nanofiber membranes with an even distribution of diameter, an optimal conductivity, good hydrophilicity, appropriate specific surface area and optimal thermal stability. Therefore, needleless dynamic linear electrospinning is beneficial to produce high quality Gr-AP porous nanofiber membranes, and the optimal parameters can be used in artificial nerve conduits and serve as a valuable reference for mass production of nanofiber membranes.

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 714 ◽  
Author(s):  
Ting-Ting Li ◽  
Yanqin Zhong ◽  
Mengxue Yan ◽  
Wei Zhou ◽  
Wenting Xu ◽  
...  

In this study, a self-made continuous needleless dynamic linear electrospinning technique is employed to fabricate large-scale graphene (Gr)/carbon nanotubes (CNT)/polyvinyl alcohol (PVA)/sodium alginate (SA) nanofibrous membranes. The synergistic effect of Gr and CNT fillers in the PVA/SA membrane is explored in depth by changing the volume ratio (v/v) of Gr and CNT as 10:0, 8:2, 6:4, 4:6, 2:8, and 0:10. Microstructure, functional group, conductivity, and hydrophilicity of PVA/SA/Gr/CNT membranes was characterized. Results show that the linear electrode needleless electrospinning technique can be spun into 200-nm diameter fibers. The PVA/SA/Gr/CNT fibrous membrane has good hydrophilicity and thermal stability. A Gr/CN ratio of 6:4 possessed the optimal synergistic effect, which showed the lowest surface resistivity of 2.53 × 103 Ω/m2. This study will provide a reference for the large-scale preparation of nanofibrous membrane used as a artificial nerve conduit in the future.


1958 ◽  
Vol 36 (1) ◽  
pp. 1115-1119
Author(s):  
R. O. Hurst

Isolation of deoxyribonucleate from a concentrated solution of thymonucleoprotein has been achieved by disruption of the protein nucleate bond with potassium thiocyanate, adsorption of the protein on celite, and alcohol precipitation of the deoxyribonucleate from aqueous salt solution. Highly polymerized nucleate can be obtained readily from 1 lb of calf thymus tissue in high yield.


2011 ◽  
Vol 1323 ◽  
Author(s):  
Y. Liu ◽  
F.D. Jiang ◽  
S. Wang ◽  
Y. Zeng ◽  
W. Shan

ABSTRACTSelective emitter structure has long been regarded as a good and relatively simple approach to improve the energy conversion efficiency of Si wafer-based single-junction photovoltaic (PV) cells. Recently emerged double printing method, on the other hand, potentially has the capability of improving the efficiency with no requirement for device structure modification. The manufacturability of these two approaches has been studied on a mass-production platform at JA Solar recently with large scale sampling. The experimental results collected from over two hundred thousand cells demonstrated that both approaches are capable of achieving significant conversion-efficiency gain in a cost-effective way with high yield rate on the PV industry commonly used mass production platform currently adopted by the vast majority of cell manufacturers


1958 ◽  
Vol 36 (11) ◽  
pp. 1115-1119 ◽  
Author(s):  
R. O. Hurst

Isolation of deoxyribonucleate from a concentrated solution of thymonucleoprotein has been achieved by disruption of the protein nucleate bond with potassium thiocyanate, adsorption of the protein on celite, and alcohol precipitation of the deoxyribonucleate from aqueous salt solution. Highly polymerized nucleate can be obtained readily from 1 lb of calf thymus tissue in high yield.


2021 ◽  
Vol 16 (4) ◽  
pp. 1934578X2110076
Author(s):  
Cheng Le-qin ◽  
Ye An-qi ◽  
Zhang Hao-ran ◽  
Zhang Yue-wei ◽  
Li Ling

Ginsenoside Rg5 is a rare secondary ginsenoside with good pharmacological activity. However, preparation of Rg5 is time consuming, gives a low yield and has poor selectivity and efficiency. Therefore, the current study describes an efficient method of preparing ginsenoside Rg5 through conversion of Protopanaxadiol (PPD) type saponins in the presence of a molecular sieve and hydrochloric acid. The PPD type saponins were transformed on the surface of a molecular sieve to obtain ginsenoside Rg5 and most of the generated secondary ginsenoside was dissociates into the reaction solution, avoiding further decomposition. In addition, the optimal experimental conditions were identified to be as follows; 0.5 ml of absolute ethanol, 0.2 mol/L of hydrochloric acid, 12.5 mg of a 4A molecular sieve, a reaction time of 2.5 hours and a reaction temperature of 70 ℃. Under these experimental conditions, yields of upto 63.2% were obtained for ginsenoside Rg5. Moreover, the hydrochloric acid-catalyzed preparation of ginsenoside Rg5 effectively inhibited its decomposition in the presence of a molecular sieve. The method is therefore suitable for laboratory and industrial production with the advantages of large-scale preparation and high-yield.


2021 ◽  
pp. 004051752110536
Author(s):  
Xiaodong Jiang ◽  
Caixia Sang ◽  
Jiankun Wang ◽  
Jing Guo

In this research, electrospinning was used to prepare sodium alginate (SA)/polyvinyl alcohol (PVA) composite nanofiber membranes. Effects of electrospinning parameters on the morphology and fiber diameter were investigated, and an orthogonal design was chosen to optimize the parameters. The optimized nanofiber membranes were applied as an adsorbent for the removal of methylene blue (MB), basic fuchsin (BF), and methyl orange (MO). Kinetic and isotherm of adsorption and effects of different experimental conditions such as pH, contact time, and initial dye concentration on adsorption capacity were investigated. It was found that the optimum parameters for the nanofiber membranes were SA/PVA blend ratios (3:7), electric field strength (20 kV), flow rate (0.05 mL/h), and distance (12.5 cm) between the syringe needle and collector, and the mean fiber diameter of the optimized membranes was 99.58 nm. The adsorption of nanofiber membranes was well described by the pseudo-second-order adsorption kinetic model and the Langmuir model, indicating that the adsorption mechanism was chemisorption by a monolayer. Based on the Langmuir model, the adsorption capacities for MB, BF, and MO were 9.25 mg/g, 9.02 mg/g, and 7.35 mg/g, respectively.


2019 ◽  
Vol 33 (32) ◽  
pp. 1950385
Author(s):  
Y. Z. Zhao ◽  
D. X. Du ◽  
Y. H. Wang

We reported a simple, high yield and large-scale preparation method for silver nanoparticles. Silver nanoparticles with 8–13 nm in diameter were successfully synthesized by silver nitrate as raw material, sodium borohydride as reducing agent, dispersan-5040 (polycarboxylate sodium salt) as surface modifier in aqueous solution. The effects of sodium borohydride and dispersan-5040 on the morphologies of silver nanoparticles were investigated. Further, the conductive inks were prepared with as-synthesized silver nanoparticles as conductive fillers in the presence of deionized (DI) water and additives. The effects of conductive fillers and additives on the pH, conductivity, surface tension and viscosity of the inks were investigated. The conductive patterns were fabricated by inkjet printer and their performances were studied. The sheet resistances of the printed pattern with seven-layer was 1.2 [Formula: see text] when the printed pattern was heat-treated at 120[Formula: see text]C for 60 min. We succeeded in printing a simple conductive circuit on photographic paper, which can light three 0.06 W LED beads. The successful fabrication of the functional circuit proves the feasibility of the ink and provides some ideas for future paper-based circuits.


Author(s):  
J. Liu ◽  
N. D. Theodore ◽  
D. Adams ◽  
S. Russell ◽  
T. L. Alford ◽  
...  

Copper-based metallization has recently attracted extensive research because of its potential application in ultra-large-scale integration (ULSI) of semiconductor devices. The feasibility of copper metallization is, however, limited due to its thermal stability issues. In order to utilize copper in metallization systems diffusion barriers such as titanium nitride and other refractory materials, have been employed to enhance the thermal stability of copper. Titanium nitride layers can be formed by annealing Cu(Ti) alloy film evaporated on thermally grown SiO2 substrates in an ammonia ambient. We report here the microstructural evolution of Cu(Ti)/SiO2 layers during annealing in NH3 flowing ambient.The Cu(Ti) films used in this experiment were prepared by electron beam evaporation onto thermally grown SiO2 substrates. The nominal composition of the Cu(Ti) alloy was Cu73Ti27. Thermal treatments were conducted in NH3 flowing ambient for 30 minutes at temperatures ranging from 450°C to 650°C. Cross-section TEM specimens were prepared by the standard procedure.


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