scholarly journals Self-Supporting Three-dimensional Electrospun Nanofibrous Membrane for Highly Efficient Air Filtration

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2567
Author(s):  
Gaofeng Zheng ◽  
Zungui Shao ◽  
Junyu Chen ◽  
Jiaxin Jiang ◽  
Ping Zhu ◽  
...  

High-performance air filtration was the key to health protection from biological and ultrafine dust pollution. A self-supporting, three-dimensional (3D) nanofibrous membrane with curled pattern was electrospun for the filtration, of which the micro-fluffy structure displayed high-filtration efficiency and low-pressure drop. The flow field in the 3D filtration membrane was simulated to optimize the process parameters to increase the filtration performance. The qualification factor increased from 0.0274 Pa−1 to 0.0309 Pa−1 by 12.77% after the optimization of the electrospinning parameters. The best filtration efficiency and pressure drop were 93.6% and 89.0 Pa, separately. This work provides a new strategy to fabricate 3D structures through the construction of fiber morphology and promotes further improvement of air filtration performance of fibrous filters.

2017 ◽  
Vol 748 ◽  
pp. 423-427
Author(s):  
Jin Yu Zhao ◽  
Zhao Lin Liu ◽  
Ju Chuan Shan

Polyvinyl alcohol (PVA) nanofibrous membrances for effective air filtration were fabricated by electrospinning. Tunable fiber morphologies can be formed by facilely regulating the solution concentration and the applied voltage, and their effect on filtration performance of the PVA membrances were also investigeted. Results show that the PVA membrance exhibits high filtration efficiency of 97.1% and low pressure drop of 113 Pa when the PVA concentration is 8 wt% and the applied voltage is 15 kV with a tip-to-collector distance of 15 cm and a feed rate of 1 ml/h.


2011 ◽  
Vol 236-238 ◽  
pp. 1885-1888
Author(s):  
Han Wang ◽  
Zuo Yi Yang ◽  
Jin Yong Liu ◽  
Gao Feng Zheng ◽  
Ling Min Chen

High filtration efficiency of nanofibrous membrane has been proved in air filtration area, but, in addition to filtration efficiency, pressure drop is another important characteristic of fibrous filter. Because pressure-drop is related to energy wastage of filtration, it’s necessary to study. While there are not enough studies dedicated to pressure-drop of nanofibrous membrane filters. Here, different thickness PVA nanofibrous membranes were made by electrospinning, and they deposited on cotton scaffolds to form nanofibrous filter samples. Through testing these samples, we found as thickness of nanofibrous membrane increased, pressure-drop rose almost linearly, while filtration efficiency presented a different change trend. When thickness of nanofibrous membrane reaching a point, filtration efficiency attained extreme limit, even if increasing thickness nanofibrous membrane, filtration efficiency only rose limitedly, but pressure-drop still increased rapidly. At the same time, we found despite the thickness of nanofibrous membrane was thinner than conventional fibrous filter, pressure-drop of nanofibrous filter was obviously higher than conventional fibrous filter. So it’s remarkable phenomena. Through theoretical analysis and simulation, the causation of high pressure-drop of nanofibrous filter was discussed and provided. Decreasing diameter of fiber caused resistance performance change. It’s necessary to carry on a further research.


2011 ◽  
Vol 474-476 ◽  
pp. 2016-2019 ◽  
Author(s):  
Han Wang ◽  
Zuo Yi Yang ◽  
Jin Yong Liu ◽  
Gao Feng Zheng ◽  
Yin Ping Liu

When nanofibers could be made last century, its filtration potential was expected in a lot of professional fields, such as building industry, medical industry and Environmental protection industry. In the present study, in order to prove and explain its performances, nanofibrous membrane with given thickness was electrospun with 8% PVA solution on conventional cotton scaffold. Then by means of special air filtration test system, the filtration performances between PVA nanofibrous membrane and conventional fibrous filters were confirmed and compared. Besides, the filtration efficiencies of particles distribution 0.3-5um were attained, and at the same time, another important parameter, pressure-drops, could be observed, too. Through data analysis, the differences of filtration performances were verified. Despite the fact that nanofibrous membrane had higher pressure-drops, its filtration efficiency could reach startlingly 99% for some given particles. In succession, SEM was used to observe the particles distribution in filter, and the different filtration mechanisms were analyzed and discussed with SEMS images. Furthermore, we found that the direct inception and the inertial impact improved nanofiber filtration efficiency, while too small diameter of nanofiber induced higher pressure-drops. In general, nanofibers have huge value in air filtration application.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4774
Author(s):  
Chao Liu ◽  
Zijian Dai ◽  
Bin He ◽  
Qin-Fei Ke

Electret melt-blown nonwovens are widely used for air purification due to their low pressure drop and high filtration efficiency. However, the charge stability could be affected by the ambient temperature and humidity, reducing the filtration efficiency, resulting in the electret melt blown filter not providing effective protection. Herein, we used corona charge to prepare electret melt-blown nonwovens and systematically studied the effects of different temperature and humidity on the structure, morphology, filtration performance, and surface potential within 24 h. The effect of treatment temperature and humidity on pressure drop was minimal because the fiber morphology and web structure of melt-blown nonwovens were not damaged. When the treatment temperature was lower than 70 °C, the effect on the filtration efficiency of the sample was small, but when the temperature increased to 90 or 110 °C, the filtration efficiency decreased significantly with the increase of the treatment time, and the surface potential also declined similarly. In conclusion, high temperatures will lead to charge escape and reduce the electrostatic adsorption effect. Furthermore, at the same temperature, increasing relative humidity can accelerate the charge release and make the filtration efficiency drop more. After the sample was treated at 110 °C and 90% relative humidity for 24 h, the filtration efficiency decreased from 95.49% to 38.16% at a flow rate of 14.16 cm s−1, and the surface potential dropped to the lowest value of −1.01 kV. This result shows that all links of electret melt-blown filter material from raw material to final use should be avoided in high temperature and high humidity conditions to ensure the protection effect.


2021 ◽  
Vol 32 (24) ◽  
pp. 245707
Author(s):  
Jiaxin Jiang ◽  
Zungui Shao ◽  
Xiang Wang ◽  
Ping Zhu ◽  
Shiqing Deng ◽  
...  

Author(s):  
chengwei xu ◽  
chenglong xiao ◽  
Yan yu ◽  
xiaodong si

The drainage layer strategy is a common method for improving filtration performance of coalescing filter. In this study, using the commercial glass fibrous filters, the influence of sub-high efficiency drainage layers on high efficiency coalescing filters were investigated experimentally. The efficiency of coalescing filter slight increases, whereas the total wet pressure drop reduces 0.32 kPa after assembling drainage layer. In addition, the influence of pore size, thickness and wettability on performance were evaluated. While the pore size of drainage layer decrease, the wet pressure drop reduces and quality factor increase. Likewise, the thickness of drainage layer also has positive effect on filtration performance. By contrast, the wettability has a weak affect on the filtration performance. As different coalescing filter with the same drainage layer, the improvement in the filtration performance increase with the decrease of pore size difference between the coalescing and drainage layers.


Author(s):  
Matthew McCormack ◽  
Fengzhou Fang ◽  
Jufan Zhang

AbstractConjugate heat transfer is numerically investigated using a three-dimensional computational fluid dynamics approach in various microchannel geometries to identify a high-performance cooling method for piezoelectric ceramic stacks and spindle units in high-precision machines. Straight microchannels with rectangular cross sections are first considered, showing the performance limitations of decreasing the size of the microchannels, so other solutions are needed for high applied heat fluxes. Next, many microchannel designs, focusing on streamwise geometric variation, are compared to straight channels to assess their performances. Sinusoidally varying channels produce the highest heat transfer rates of those studied. Thus, their optimization is considered at a channel width and height of 35 and 100 μm, respectively. Heat transfer increases as the amplitude and spatial frequencies of the channels increase due to increased interfacial surface area and enhanced Dean flow. The highest performance efficiencies are observed at intermediate levels of amplitude and frequency, with efficiency decreasing as these geometric parameters are increased further at the onset of flow separation. The sinusoidal channel geometries are then optimized with respect to minimizing the system’s pressure drop for all applied heat fluxes between 5690 and 6510 kW/m2. Doing so created an optimal geometry curve and showed that all geometries in this region had amplitudes close to 40 μm. Therefore, imposing a fixed heat flux requirement for a case study of cooling piezoelectric ceramics, the optimized sinusoidal geometry decreases the system pressure drop by 79% relative to a straight channel while maintaining a larger minimum feature size.


2020 ◽  
pp. 152808372096141
Author(s):  
Chi Zou ◽  
Yunlong Shi ◽  
Xiaoming Qian

The glass fiber felt made through flame blowing process was characterized on morphology and its filtration performance. Fiber diameter has been measured through SEM and BET methods. Theoretical calculations on pressure drop and filtration efficiency were developed and compared with the experimental measurement. The discrepancy between the calculated results and measurement on filtration efficiency is derived from the presence of fine fiber (<0.5µm) in the glass fiber felt, which contributes to the actual high filtration efficiency in measurement. The multiple micro-layered structure in glass fiber felt, which improves the dust holding capacity and enables glass fiber felt as a depth filter. Glass fiber felt showed a longer duration of the slow increase region for pressure drop build-up comparing to other filter materials with lower averaged pressure drop through its filtration service life. Furthermore, quality factor calculation has been developed for prediction on the energy cost performance of the filters based on the pressure drop, separation efficiency and dust holding capacity.


2020 ◽  
pp. 152808372092377
Author(s):  
Bilal Zaarour ◽  
Hussen Tina ◽  
Lei Zhu ◽  
XiangYu Jin

Engineering the surface morphology of fibers has been attracting significant consideration in various areas and applications. In this study, polyvinylidene fluoride (PVDF) branched nanofibers with a diameter of less than 50 nm are electrospun directly at a low relative humidity by adding tetrabutylammonium chloride. The effects of the branched structure on the specific surface area and pore size distribution are investigated, and the filtration properties of the air filter based on branched nanofiber webs with different basis weights are studied. The results exhibit that the air filter based on PVDF branched nanofibers with the basis weight of 1 g/m2 has an outstanding filtration efficiency (99.999%) to 0.26 µm sodium chloride particles under the pressure drop of 126.17 Pa. We believe that this study can be used as a useful reference for the preparation of branched nanofibers through one-step electrospinning.


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