High-performance anti-haze window screen based on multiscale structured polyvinylidene fluoride nanofibers

2022 ◽  
Vol 607 ◽  
pp. 711-719
Author(s):  
Junpeng Xiong ◽  
Weili Shao ◽  
Ling Wang ◽  
Chen Cui ◽  
Yanfei Gao ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
High Performance ◽  
Window Screen

scholarly journals Design, fabrication and experimental studies of compliant flexure diaphragm for micro pump

2018 ◽  
Vol 7 (2.21) ◽  
pp. 66 ◽  
Author(s):  
R Roopa ◽  
P Navin Karanth ◽  
S M. Kulkarni
Keyword(s):  
Polyvinylidene Fluoride ◽  
High Performance ◽  
Experimental Studies ◽  
Single Layer ◽  
Operating Voltage ◽  
Driving Voltage ◽  
Element Analysis ◽  
Central Deflection ◽  
Large Numbers ◽  
Micro Pump

This study reports the performance of piezo actuated compliant flexure diaphragm for micropump and MEMS application. To achieve the high performance of diaphragm at the low operating voltage compliant flexure diaphragm design is introduced. Very limited work has done on the diaphragms of micropump. Large numbers of mechanical micropumps have used plane diaphragms. The central deflection of diaphragm plays an important role in defining the micropump performance. The flow rate of mechanical type micropump strongly depends on the central deflection of diaphragm. In this paper compliant flexure diaphragms are designed for micropump to achieve higher deflection at lower operating voltage. Finite element analysis of compliant flexure diaphragm with single layer PVDF (Polyvinylidene fluoride) actuator is simulated in COMSOL. Compliant flexure diaphragms with a different number of flexures are analyzed. The central deflection of compliant flexure diaphragms is measured for driving voltages of 90V to 140V in 10 steps. The deflection of the compliant flexure diaphragm mainly depends on flexure width and length, the number of flexures in the diaphragm, PVDF thickness, diaphragm thickness and driving voltage. Use of compliant flexure diaphragm for micropump will reduce the mass and driving voltage of micropump. An attempt is made to compare the results of compliant flexure diaphragms with plane diaphragms. From the experimental results it is noticed that the compliant flexure diaphragm deflection is twice that of the plane diaphragm at same driving voltage. Deflection of three flexure and four flexure compliant diaphragms is 10.5µm and 11.5µm respectively at 140V.  

Pervaporative desalination of seawater using a polyvinylidene fluoride based membrane

2017 ◽  
Vol 18 (5) ◽  
pp. 1674-1681 ◽  
Author(s):  
F. U. Nigiz ◽  
N. D. Hilmioglu
Keyword(s):  
Fresh Water ◽  
Polyvinylidene Fluoride ◽  
High Performance ◽  
Potable Water ◽  
Effective Properties ◽  
Cost Effective ◽  
Porous Membranes ◽  
Scientific Investigations ◽  
Different Temperatures ◽  
Energy Strategies

Abstract Producing a fresh water supply by converting non-potable water is an attractive solution when water is scarce. According to the energy strategies of different countries, various seawater purification techniques such as distillation and reverse osmosis (RO) are used to produce fresh water. Due to the selective separation capability and cost-effective properties, membrane based methods such as RO, electrodialysis, and ultra/micro/nano/filtration are prevalent, especially in Europe. Recently, innovative desalination technologies have been investigated by researchers. Among them, pervaporative separation, in which non-porous membranes are used, appears to be an emerging and promising method. The key part of the system is the membrane. Hence, scientific investigations are focused on the production of high-performance membranes. In this study, non-porous polyvinylidene fluoride (PVDF) and polyvinyl pyrrolidone (PVP) blend membranes were prepared in different PVDF/PVP ratios and Marmara seawater was desalinated using the pervaporation method at different temperatures. Desalination performance was evaluated as a function of flux and salt retention. The highest salt retention of 99.90% and flux of 1.60 kg/m2.h were obtained at 60 °C when the PVDF/PVP ratio was 1.5.

scholarly journals Sintered polymeric binders for Li-ion battery alloy anodes

2018 ◽  
Vol 96 (7) ◽  
pp. 765-770 ◽  
Author(s):  
T.D. Hatchard ◽  
R.A. Fielden ◽  
M.N. Obrovac
Keyword(s):  
Polyvinylidene Fluoride ◽  
High Performance ◽  
Cycling Performance ◽  
Superior Performance ◽  
Capacity Fade ◽  
High Carbon ◽  
Carbon Yield ◽  
Carbon Coatings ◽  
Alloy Particles ◽  
Polymeric Binders

The cycling performance in lithium half cells of Si alloy electrodes with polyvinylidene fluoride or polyimide binders were evaluated after the electrodes were cured at temperatures below and above the binder carbonization temperature. After carbonization, the cycling performance of electrodes using polyvinylidene fluoride binder improved considerably but still suffered from capacity fade. Electrodes with carbonized polyimide binder had superior performance and showed no capacity fade after 100 cycles. The superior performance of carbonized polyimide electrodes is thought to be related to polyimide’s high carbon yield upon heating, resulting in the formation of a uniform carbon coating on alloy surfaces. These results suggest that new high performance binders for alloy electrodes might be derived by the carbonization of polymers with a high carbon yield that lead to the formation of uniform carbon coatings on alloy particles.

scholarly journals Membrane Biofouling Control by Surface Modification of Quaternary Ammonium Compound Using Atom-Transfer Radical-Polymerization Method with Silica Nanoparticle as Interlayer

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 417
Author(s):  
Lehui Ren ◽  
Meng Ping ◽  
Xingran Zhang
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Quaternary Ammonium ◽  
Polyvinylidene Fluoride ◽  
High Performance ◽  
Membrane Surface ◽  
Silica Nanoparticle ◽  
Ammonium Compound ◽  
Atom Transfer ◽  
Nanoparticle Layer

A facile approach to fabricate antibiofouling membrane was developed by grafting quaternary ammonium compounds (QACs) onto polyvinylidene fluoride (PVDF) membrane via surface-initiated activators regenerated by electron transfer atom-transfer radical-polymerization (ARGET ATRP) method. During the modification process, a hydrophilic silica nanoparticle layer was also immobilized onto the membrane surface as an interlayer through silicification reaction for QAC grafting, which imparted the membrane with favorable surface properties (e.g., hydrophilic and negatively charged surface). The QAC-modified membrane (MQ) showed significantly improved hydrophilicity and permeability mainly due to the introduction of silica nanoparticles and exposure of hydrophilic quaternary ammonium groups instead of long alkyl chains. Furthermore, the coverage of QAC onto membrane surface enabled MQ membrane to have clear antibacterial effect, with an inhibition rate ~99.9% of Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive), respectively. According to the batch filtration test, MQ had better antibiofouling performance compared to the control membrane, which was ascribed to enhanced hydrophilicity and antibacterial activity. Furthermore, the MQ membrane also exhibited impressive stability of QAC upon suffering repeated fouling–cleaning tests. The modification protocols provide a new robust way to fabricate high-performance antibiofouling QAC-based membranes for wastewater treatment.

High-performance n-type Ta4SiTe4/polyvinylidene fluoride (PVDF)/graphdiyne organic-inorganic flexible thermoelectric composites

2021 ◽  
Author(s):  
Sanyin Qu ◽  
Chen Ming ◽  
Pengfei Qiu ◽  
Kunqi Xu ◽  
Qing Xu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Polyvinylidene Fluoride ◽  
High Performance ◽  
The Past ◽  
P Type ◽  
Flexible Thermoelectric

In the past decade, the development of high-performance p-type flexible organic-inorganic thermoelectric composites based on nanocarbons (e.g. carbon nanotubes and graphene) has achieved unprecedented success, but the progress in n-type...

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