Electrospun cellulose acetate nanofibers for airborne nanoparticle filtration

2018 ◽  
Vol 89 (15) ◽  
pp. 3137-3149 ◽  
Author(s):  
Joerg Ahne ◽  
Qinghai Li ◽  
Eric Croiset ◽  
Zhongchao Tan
Keyword(s):  
Sodium Chloride ◽  
Cellulose Acetate ◽  
Quality Factor ◽  
Size Distribution ◽  
Deposition Time ◽  
Solution Concentration ◽  
Filtration Efficiency ◽  
Laboratory Setting ◽  
Fiber Size ◽  
Airborne Nanoparticle

Reported in this paper are the effects of tip-to-collector distance, voltage, deposition time and solution concentration on the fiber size distribution and filter quality factor of electrospun cellulose acetate (CA)-based nanofibers. Nanofibrous filter samples were produced by electrospinning in a laboratory setting. The CA solutions were prepared by diluting various concentrations of CA in a 2:1 (w:w) ratio of N,N-dimethylacetamide (concentration 10–20 wt.%). The electrospinning voltages ranged from 8–12 kV, with distances from 10–15 cm and deposition times of up to 30 minutes. The produced nanofibrous filter samples were then analyzed in terms of fiber size distribution and filter quality factor using nanosized sodium chloride particles ranging from 4–240 nm in diameter. The maximum filtration efficiency measured was 99.8% for filter samples obtained with an overall deposition time of 30 minutes. The maximum filter quality factor was 0.14 Pa−1 for a CA concentration of 20 wt.% and a tip-to-collector distance of 15 cm. The average fiber diameters of the fibers were between 175 and 890 nm, and CA concentrations below 15% led to the formation of beads.

scholarly journals Preparation of electrospun nanofiber membrane for air filtration and process optimization based on BP neural network

2021 ◽  
Author(s):  
Le Kang ◽  
Yuankun Liu ◽  
Liping Wang ◽  
Xiaoping Gao
Keyword(s):  
Neural Network ◽  
Quality Factor ◽  
Flow Rate ◽  
Bp Neural Network ◽  
Polyvinylidene Fluoride ◽  
Orthogonal Experiment ◽  
Solution Concentration ◽  
Filtration Efficiency ◽  
Air Filtration ◽  
Filtration Resistance

Abstract The filtration layer in a medical protective mask can effectively prevent aerosol particles that might carry viruses from air. A nanofiber/microfiber composite membrane (NMCM) was successfully fabricated by electrospinning polyvinylidene fluoride (PVDF) nanofibers collected on the electrified and melt-blown polypropylene (PP) nonwovens, aiming to improve the filtration efficiency and reduce the resistance of respiration of mask. A four-factor and three-level orthogonal experiment was designed to study the effect of electrospinning parameters such as spinning solution concentration, voltage, tip-collect distance (TCD), and flow rate of solution on the filtration efficiency, resistance of respiration as well as quality factor of NMC developed to predict the resistance of respiration. Experimental results demonstrated that the filtration efficiency of NMCM≥95% in comparison to that of electrified and melt-blown PP nonwovens 79.38%, which increases by 19.68%. Additionally, the average resistance of respiration is 94.78 Pa, which meets the protection requirements. Multivariate analysis of variance indicated that the resistance of respiration of the NMCM has significantly dependent on the concentration, voltage, TCD, and flow rate of the spinning solution and the quality factor of the NMCM has dependent on the resistance of respiration. The air permeability ranges from 166.23 to 314.35mm/s, which is inversely proportional to the filtration resistance. As far as the filtration resistance is concerned, the optimal spinning parameters were obtained as follows. The concentration of spinning solution is 15%, the voltage is 27 kV, the TCD is 22 cm, and the flow rate is 2.5 mL/h. The relative error of the BP neural network varies from 0.49505% to 1.49217%, i.e. the error value varies from 0.17 to1.33 Pa. The predicted resistance of respiration corresponding to the optimal process is 68.1374 Pa.

scholarly journals An Improved Theoretical Model of Cigarette Smoke Filtration across Mono-Segment Cellulose Acetate Filters

2015 ◽  
Vol 26 (5) ◽  
Author(s):  
Du Wen ◽  
Wen Jianhui ◽  
Peng Bing ◽  
Zhang Xiaobin ◽  
Xie Fuwei ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Flow Velocity ◽  
Cellulose Acetate ◽  
Cigarette Smoke ◽  
Particle Diameter ◽  
Filtration Efficiency ◽  
Inertial Impaction ◽  
Fiber Size ◽  
The Difference ◽  
Health Canada

SummaryAn improved theoretical model was presented to predict the filtration efficiency of cigarette filters. Filtration equations of single fibers considering the interference of neighboring fibers were applied in the model. Cellulose acetate fibers in cigarette filters were approximated as cylinders. The fiber size was adjusted by its size projected on the flow field. The solid fraction of fibers in cigarette filters was recalculated using the size of the virtual cylinders. The varying flow velocity during smoking was taken into account when calculating the filtration efficiency. The effective hydrodynamic particle diameter of cigarette smoke was estimated to be 0.44 μm by the difference of filtration efficiencies under ISO and Health Canada Intense (HCI) smoking regimes. Filtration contributions due to diffusion, interception and inertial impaction were 62%, 32% and 6%, respectively, at a flow velocity of 0.38 m/s for particles of 0.44 μm diameter. The effect of inertial impaction was insignificant but not negligible under ISO smoking regime. The measured and predicted efficiencies of two cigarette samples were compared and satisfactory agreement was obtained. [Beitr. Tabakforsch. Int. 26 (2015) 232-240]

Development, Evaluation and Optimization of Osmotic Controlled Tablets of Aceclofenac for Rheumatoid Arthritis Management

2019 ◽  
Vol 9 (1) ◽  
pp. 29-36
Author(s):  
Bijaya Ghosh ◽  
Niraj Mishra ◽  
Preeta Bose ◽  
Moumita D. Kirtania
Keyword(s):  
Rheumatoid Arthritis ◽  
Polyethylene Glycol ◽  
Sodium Chloride ◽  
Cellulose Acetate ◽  
Hydroxypropyl Methylcellulose ◽  
Release Profile ◽  
Polyethylene Glycol 400 ◽  
Permeable Membrane ◽  
Cumulative Release ◽  
The Core

Objective: Rheumatoid arthritis is a dreaded disease, characterized by pain, inflammation and stiffness of joints, leading to severe immobility problems. The disease shows circadian variation and usually gets aggravated in early morning hours. Aceclofenac, a BCS Class II compound is routinely used in the treatment of pain and inflammation associated with rheumatoid arthritis. The objective of this study was to develop an osmotic delivery system of Aceclofenac that after administration at bedtime would deliver the drug in the morning hours. </P><P> Methods: A series of osmotically controlled systems of aceclofenac was developed by using lactose, sodium chloride and hydroxypropyl methylcellulose K100M as osmogens. Cellulose acetate (2% w/v in acetone) with varying concentrations of polyethylene glycol-400 was used as the coating polymer to create semi permeable membrane and dissolution was carried out in 290 mOsm phosphate buffer. Formulation optimization was done from four considerations: cumulative release at the end of 6 hours (lag time), cumulative release at the end of 7 hours (burst time), steady state release rate and completeness of drug release. </P><P> Results: A formulation having swelling polymer hydroxypropyl methylcellulose in the core and lactose and sodium chloride as osmogens, polyethylene glycol-400 (16.39 %) as pore former, with a coating weight of 5% was a close fit to the target release profile and was chosen as the optimum formulation. Conclusion: Aceclofenac tablets containing lactose, HPMC and sodium chloride in the core, given a coating of cellulose acetate and PEG-400 (5% wt gain), generated a release profile for optimum management of rheumatoid arthritic pain.

scholarly journals Development of Needle-Punched Nonwoven Fabrics from Reclaimed Fibers for Air Filtration Applications

2014 ◽  
Vol 9 (1) ◽  
pp. 155892501400900 ◽  
Author(s):  
S. Sakthivel ◽  
Anban J.J. Ezhil ◽  
T. Ramachandran
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Air Permeability ◽  
Filtration Efficiency ◽  
Raw Material ◽  
Fine Tuning ◽  
Physical Parameters ◽  
Air Filtration ◽  
Nonwoven Fabrics

This paper reports an investigative study on the fabrication and measurement of the air permeability, mechanical properties, pore size distribution, and filtration efficiency of different nonwoven fabrics produced from reclaimed fibers by analytically changing the machine variables to manipulate the physical parameters of the nonwoven fabrics. Reclaimed fiber of cotton (60%) and polyester (40%) blend was used, so that the prospect of value addition to an inexpensive source of raw material could be explored. The changes in air permeability were interpreted in terms of fabric density profile and pore size distribution. The filtration parameters of filtration efficiency, dust holding capacity, and pressure drop were also calculated. Additionally, the effects of calendering on pore size and filtration properties were evaluated to discover the opportunity of fine-tuning and the performance of the filters. The outcome in this study reflected an overall development in all filtration characteristics due to the calendering operation.

scholarly journals Experimental Study of the Microstructural Evolution of Glauberite and Its Weakening Mechanism under the Effect of Thermal-Hydrological-Chemical Coupling

Processes ◽  
2018 ◽  
Vol 6 (8) ◽  
pp. 99 ◽  
Author(s):  
Shuzhao Chen ◽  
Donghua Zhang ◽  
Tao Shang ◽  
Tao Meng
Keyword(s):  
Sodium Chloride ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Crack Nucleation ◽  
Chloride Concentration ◽  
Solution Concentration ◽  
Expansion Velocity ◽  
Research Subjects ◽  
Characteristic Index ◽  
Chemical Coupling

The microstructures of rock gradually evolve with changes in the external environment. This study focused on the microstructure evolution of glauberite and its weakening mechanism under different leaching conditions. The porosity were used as a characteristic index to study the effect of brine temperature and concentration on crack initiation and propagation in glauberite. The research subjects were specimens of ϕ3 × 10 mm cylindrical glauberite core, obtained from a bedded salt deposit buried more than 1000 m underground in the Yunying salt formation, China. The results showed that when the specimens were immersed in solution at low temperature, due to hydration impurities, cracks appeared spontaneously at the centre of the disc and the solution then penetrated the specimens via these cracks and dissolved the minerals around the crack lines. However, with an increase of temperature, the dissolution rate increased greatly, and crack nucleation and dissolved regions appeared simultaneously. When the specimens were immersed in a sodium chloride solution at the same concentration, the porosity s presented gradual upward trends with a rise in temperature, whereas, when the specimens were immersed in the sodium chloride solution at the same temperature, the porosity tended to decrease with the increase of sodium chloride concentration. In the process of leaching, the hydration of illite, montmorillonite, and the residual skeleton of glauberite led to the expansion of the specimen volume, thereby producing the cracks. The diameter expansion rate and the expansion velocity of the specimen increased with temperature increase, whereas, due to the common-ion effect, the porosity of the specimen decreases with the increase of sodium chloride solution concentration.

scholarly journals Effect of zno nanoparticles on diameter of bubbfil PVA/ZnO nanofibers

2015 ◽  
Vol 19 (4) ◽  
pp. 1447-1449
Author(s):  
Cui-Juan Ning ◽  
Hua Liu ◽  
Na Si ◽  
Ji-Huan He
Keyword(s):  
Size Distribution ◽  
Poisson Distribution ◽  
Gaussian Distribution ◽  
Zno Nanoparticles ◽  
Nano Zno ◽  
Fiber Size ◽  
Zno Nanofibers

The PVA/ZnO nanofibers are obtained by the bubbfil spinning. Distribution of fiber size is tenable by nano-ZnO concentration. Experiment reveals fiber size distribution changes from Gaussian distribution to Poisson distribution when ZnO concentration varies gradually from 2 wt.% to 15 wt.%.

scholarly journals Antimicrobial Air Filters Using Natural Sea Salt Particles for Deactivating Airborne Bacterial Particles

2019 ◽  
Vol 17 (1) ◽  
pp. 190
Author(s):  
Sang Bin Jeong ◽  
Ki Joon Heo ◽  
Byung Uk Lee
Keyword(s):  
Escherichia Coli ◽  
Environmental Exposure ◽  
Staphylococcus Epidermidis ◽  
Deposition Time ◽  
Filtration Efficiency ◽  
Sea Salt ◽  
Air Filters ◽  
Air Filter ◽  
Aerosol Process ◽  
Microbial Contaminants

We developed an antimicrobial air filter using natural sea salt (NSS) particles. Airborne NSS particles were produced via an aerosol process and were continuously coated onto the surface of an air filter under various deposition times. The filtration efficiency and bactericidal performance of the NSS-coated filter against aerosolized bacterial particles (Staphylococcus epidermidis, Escherichia coli) were evaluated quantitatively. The filtration efficiency of the tested filter ranged from 95% to 99% depending on the deposition time, and the bactericidal performance demonstrated efficiencies of more than 98% against both tested bacterial bioaerosols when the NSS deposition ratio was more than 500 μg/cm2. The experimental results indicated that the NSS-coated filters have the potential to be used as effective antimicrobial air filters for decreasing environmental exposure to microbial contaminants.

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