scholarly journals Fabrication of Polypropylene-g-(Diallylamino Triazine) Bifunctional Nonwovens with Antibacterial and Air Filtration Activities by Reactive Extrusion and Melt-Blown Technology

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Chao Liu ◽  
Zijian Dai ◽  
Rong Zhou ◽  
Qinfei Ke ◽  
Chen Huang
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Effect ◽  
Antibacterial Property ◽  
Reactive Extrusion ◽  
Filtration Efficiency ◽  
Air Filtration ◽  
Filter Materials ◽  
Innovative Method ◽  
Extrusion Method

Air filtration materials such as protective masks can protect humans from airborne pathogens; however, most of the existing protective filtration materials are aimed to intercept bacteria. Therefore, in this work, modified polypropylene- (PP-) based melt-blown nonwovens with antibacterial property were prepared for reducing the infection rate during the filtering process. Firstly, an N-halamine precursor, 2,4-diamino-6-diallylamino-1,3,5-triazine (NDAM) monomer, was grafted with PP polymers (PP-g-NDAM) by reactive extrusion method, and the grafting effect was confirmed by nitrogen analysis and FTIR spectra. Then, the obtained PP-g-NDAM was mixed with pristine PP resins in different ratios to prepare the filter materials by melt-blown technology. Finally, the new PP-g-NDAM melt-blown filter materials were finishing treated by the chlorination and electrostatic process, which showed a high filtration efficiency with low pressure drop and a potent antibacterial effect against Escherichia coli (E. coli). This work provides an innovative method for manufacturing antibacterial filtration nonwovens, which can improve the quality of conventional filtration products.

A Study on the Antibacterial Property of the Extract from Apocynum Venetum

2011 ◽  
Vol 332-334 ◽  
pp. 164-167
Author(s):  
Zheng Li ◽  
Zhen Feng Dong ◽  
Jian Fei Zhang ◽  
Ji Xian Gong ◽  
Fan Jie Meng
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Staphylococcus Aureus ◽  
Aspergillus Niger ◽  
Antibacterial Effect ◽  
Antibacterial Property ◽  
Absolute Ethanol ◽  
Antibacterial Substance ◽  
Apocynum Venetum ◽  
Better Than

In order to determined the antibacterial property of Apocynum venetum. Three kinds of extractants (distilled water, 75% ethanol and absolute ethanol) were used to extract the leaf, stick and skin of Apocynum venetum, respectively. Flask and plate methods were used to evaluate the antibacterial property of these extracts on four kinds of classical microbiologies, Escherichia coli, Staphylococcus aureus, Saccharomyces cerevisiae and Aspergillus niger, respectively. The results showed that the antibacterial rate of extract by 75 % ethanol was better than extracts by water or absolute ethanol on Escherichia coli and skin contained more antibacterial substance (on Escherichia coli) than others. The antibacterial rate of extract by distill water was better than extracts by 75 % ethanol or absolute ethanol on Staphylococcus aureus and stick contained more antibacterial substance (on Staphylococcus aureus) than others. Some of extracts had very weak antibacterial rate on Saccharomyces cerevisiae and all extracts had not antibacterial effect on Aspergillus niger.

Characterization of glass fiber felt and its performance as an air filtration media

2020 ◽  
pp. 152808372096141
Author(s):  
Chi Zou ◽  
Yunlong Shi ◽  
Xiaoming Qian
Keyword(s):  
Pressure Drop ◽  
Glass Fiber ◽  
Separation Efficiency ◽  
Theoretical Calculations ◽  
Filtration Efficiency ◽  
Air Filtration ◽  
Slow Increase ◽  
Filter Materials ◽  
Fine Fiber

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.

Material Properties Analysis with Addition of Nanofibres for Air Intake Filtration in Internal Combustion Engines

2021 ◽  
Vol 18 (1) ◽  
pp. 8621-8636
Author(s):  
T. Dziubak
Keyword(s):  
Flow Resistance ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Filtration Efficiency ◽  
Combustion Engines ◽  
Test Results ◽  
Air Filtration ◽  
Filter Media ◽  
Air Filter ◽  
Filter Materials

The aim of this study is to provide an experimental properties evaluation of a standard filter material (cellulose) and materials with fiber layer addition with small diameters (nanofibers). Filter media, including cellulose, used in the internal combustion engine inlet air filtration are made of high diameter fibres, approx. 15 µm. Significantly higher separation and filtration efficiency performance are obtained for materials with lower fibre diameters (nanofibres), however, at the expense of a significantly higher pressure drop, affecting the engine performance. Filter media manufacturers mainly specify the structure parameters (pore size, air permeability and thickness), without giving any information on the dust filtration performance and rate. The literature includes test results for models of different filter media structures. Filtration process modelling using polydisperse dust with particles of different shape and density and irregular filter media structure is possible using advanced computer techniques, however, the process is complex and requires many simplifications. Test results can be applied directly in the automotive industry. The data can be obtained by experimental tests on filter medium specimens, complete filter elements or air filters which are costly and time-consuming tests, however, those test methods are the most reliable. Conditions and testing methodology for intake air filter materials used in internal combustion engines were developed. Filtration and flow resistance efficiency and accuracy were done depending on test dust mass stopped per unit area. Tested materials filtration efficiency was assessed by a filtration quality factor, which includes experimentally determined efficiency and accuracy as well as flow resistance values. Much higher efficiency and filtration accuracy of dust grains below 5 µm in filtration materials with nanofibers addition compared to standard filtration material (filter paper) were demonstrated. For the same flow resistance values, filter materials with nanofibers addition accumulate smaller dust mass than standard filter paper. Usage of materials with nanofibers addition used in motor vehicles intake air filtration ensures their high efficiency and accuracy. It minimises its components wear, but at the expense of faster flow resistance increase, which shortens filter life and increases filter replacement frequency. Results obtained during the experimental research partly fill the gap when it comes to the basic material properties used in internal combustion engines intake air filter partitions production.

scholarly journals Experimental Study of Filtration Materials Used in the Car Air Intake

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3498
Author(s):  
Tadeusz Dziubak ◽  
Sebastian Dominik Dziubak
Keyword(s):  
Flow Resistance ◽  
Initial Period ◽  
Filter Material ◽  
Filtration Efficiency ◽  
Structure Parameters ◽  
Air Filtration ◽  
Resistance Increase ◽  
Filter Materials ◽  
Engine Component ◽  
Dust Absorption

Traditional cellulose filter media used for air filtration in vehicle engines are characterized by 99.9% filtration efficiency and accuracy above 2–5 µm. The highest engine component wear is caused by dust grains above 1 µm. Filter media with nanofiber additions provide greater filtration efficiency of dust grains below 5 µm. Filter material selection for vehicle engine air filter is a problem because their manufacturers mainly provide only the structure parameters: pore size, air permeability, and thickness. There is no information about material filtration properties using polydisperse test dust. The manuscript presents methodology and experimental test results of five samples A, B, C, D and E, filter materials differing in their chemical composition and structure parameters. In the first stage, efficiency characteristics φw, filtration accuracy dzmax and the flow resistance Δpw depending on the dust absorption coefficient km of three filter cartridges of each material, A, B, C, D and E, were determined. Then, from each material characteristics of one piece was selected in order to compare their initial and initial period efficiencies as well as changes in the flow resistance depending on the dust absorption coefficient km. Obtained results showed that the filter materials differ significantly in efficiency and accuracy values in the initial filtration period. Initial period duration is also different, i.e., filtration efficiency increasing time to a certain value, which for materials with a nanofiber layer is much shorter, which minimizes engine component wear. For materials with nanofibers, flow resistance increase intensity is greater, which results from surface filtration. Filtration efficiency of each filter material sample A, B, C, D and E was assessed with the filtration quality coefficient including the efficiency and flow resistance. In the available literature, the problem of increasing filtration efficiency in the initial period is known, but there are no results for specific filter materials. Research shows that filter material characteristics are closely related. Each increase in efficiency and accuracy of intake air filtration reduces engine components wear, but it is related to flow resistance increase in the engine intake system, which reduces its power, and increases need for more frequent filter servicing.

scholarly journals Evaluations of Electrostatic Filtration Efficiency and Antibacterial Efficacy of Antibacterial Electret Polypropylene Filters: Effects of Using Low Molecular Antibacterial Agent as Additive

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3303
Author(s):  
Jia-Horng Lin ◽  
Ying-Huei Shih ◽  
Chen-Hung Huang ◽  
Mei-Feng Lai ◽  
Shu-An Lee ◽  
...  
Keyword(s):  
Antibacterial Agent ◽  
Antibacterial Effect ◽  
Filtration Efficiency ◽  
Low Molecular Weight ◽  
Test Results ◽  
Highly Qualified ◽  
Air Filtration ◽  
E Coli ◽  
Nonwoven Fabrics ◽  
Effective Additive

In recent years, air filtration has been gaining much attention, and now people are much more concerned about antibacterial filters due to the spreading of COVID-19. The electret polypropylene (PP) nonwoven fabrics possess excellent filtration efficiency but a limited antibacterial effect against S. aureus and E. coli, and therefore triclosan is used in this study. Serving as an antibacterial agent, triclosan with a low molecular weight is an effective additive for the test results, indicating that the presence of triclosan strengthens the antibacterial effects of the filters. In addition, triclosan also strengthens the PP’s crystallinity, which in turn betters the filtration efficiency of the filters concurrently. Demonstrating powerful filtration and antibacterial performances, the antibacterial electret PP filters are highly qualified for filter applications.

scholarly journals Antibacterial and Biodegradable Electrospun Filtering Membranes for Facemasks: An Attempt to Reduce Disposable Masks Use

2021 ◽  
Vol 12 (1) ◽  
pp. 67
Author(s):  
Sofia M. Costa ◽  
Luísa Pacheco ◽  
Wilson Antunes ◽  
Ricardo Vieira ◽  
Nuno Bem ◽  
...  
Keyword(s):  
Antibacterial Effect ◽  
Natural Fibers ◽  
Inhibition Zone ◽  
Filtration Efficiency ◽  
Air Filtration ◽  
Negative Effects ◽  
Electrospinning Technique ◽  
Global Issue ◽  
Electrospun Membranes ◽  
Filter Layer

Due to the prevalence of the COVID-19 pandemic, the demand for disposable facemasks has become a global issue. Unfortunately, the use of these products has negative effects on the environment, and therefore, the use of biodegradable materials is a powerful strategy to overcome this challenge. Aligned with this concept, in this work, biodegradable facemasks were developed using poly(ε-caprolactone) (PCL) polymer and cotton natural fibers. The filter layer was produced using an electrospinning technique, since electrospun membranes present remarkable characteristics for air filtration. The electrospun membranes were functionalized with different nanoparticles (NPs), including silver (Ag), titanium dioxide (TiO2) and magnesium oxide (MgO), in order to include new properties, namely antibacterial effect. The developed membranes were characterized by FESEM, EDS, ATR-FTIR, GSDR and TGA, which confirmed the successful impregnation of NPs onto PCL membranes. The antibacterial effect and filtration efficiency were assessed, with the PCL/MgO NPs membrane presenting better results, showing inhibition zone diameters of 25.3 and 13.5 mm against Gram-positive and Gram-negative bacteria, respectively, and filtration efficiency of 99.4%. Three facemask prototypes were developed, and their filtration efficiency, air permeability and thermal comfort were evaluated. Overall, this study demonstrates the potential of PCL/NPs electrospun membranes to act as an active and biodegradable filter layer in facemasks.

Microbiological quality of residues from drinking water preparation

1995 ◽  
Vol 31 (5-6) ◽  
pp. 75-79 ◽  
Author(s):  
M. Würzer ◽  
A. Wiedenmann ◽  
K. Botzenhart
Keyword(s):  
Waste Water ◽  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Drinking Water ◽  
Water Treatment ◽  
Pathogenic Bacteria ◽  
Waste Water Treatment ◽  
Microbiological Quality ◽  
Detection Limits

In Germany the application of procedures such as flocculation and filtration in the preparation of drinking water results in the annual production of an estimated 500,000 t of sediments and sludges. Some of these residues have a potential for being reused, for example in agriculture, forestry, brickworks or waste water treatment. To assess the microbiological quality of residues from waterworks methods for the detection of enterobacteria, Escherichia coli, Salmonella, Pseudomonas aeruginosa, Legionella, poliovirus, Ascaris suis eggs and Cryptosporidium have been evaluated regarding their detection limits and were applied to various residues from German waterworks. Results show that sediments and sludges may contain pathogenic bacteria, viruses and protista. When residues from waterworks are intended to be reused in agriculture or forestry the microbiological quality should therefore be considered.

Microbiological Quality of Fresh Blue Crabmeat, Clams and Oysters

1983 ◽  
Vol 46 (11) ◽  
pp. 978-981 ◽  
Author(s):  
B. A. WENTZ ◽  
A. P. DURAN ◽  
A. SWARTZENTRUBER ◽  
A. H. SCHWAB ◽  
R. B. READ
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Microbiological Quality ◽  
Fecal Coliforms ◽  
Geometric Means ◽  
Colony Forming Units ◽  
Plate Counts ◽  
The Mean ◽  
Eastern Oysters

The microbiological quality of fresh blue crabmeat, soft- and hardshell clams and shucked Eastern oysters was determined at the retail (crabmeat, oysters) and wholesale (clams) levels. Geometric means of aerobic plate counts incubated at 35°C were: blue crabmeat 140,000 colony-forming units (CFU)/g, hardshell clams, 950 CFU/g, softshell clams 680 CFU/g and shucked Eastern oysters 390,000 CFU/g. Coliform geometric means ranged from 3,6/100 g for hardshell clams to 21/g for blue crabmeat. Means for fecal coliforms or Escherichia coli ranged from &lt;3/100 g for clams to 27/100 g for oysters, The mean Staphylococcus aureus count in blue crabmeat was 10/g.

Effect of Gamma Radiation on the Reduction of Salmonella strains, Listeria monocytogenes, and Shiga Toxin–Producing Escherichia coli and Sensory Evaluation of Minimally Processed Spinach (Tetragonia expansa)

2014 ◽  
Vol 77 (10) ◽  
pp. 1768-1772 ◽  
Author(s):  
ANA CAROLINA B. REZENDE ◽  
MARIA CRYSTINA IGARASHI ◽  
MARIA TERESA DESTRO ◽  
BERNADETTE D. G. M. FRANCO ◽  
MARIZA LANDGRAF
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Gamma Radiation ◽  
Shiga Toxin ◽  
Radiation Doses ◽  
Minimally Processed ◽  
Tetragonia Expansa ◽  
Effects Of Irradiation On ◽  
Spinach Leaves

This study evaluated the effects of irradiation on the reduction of Shiga toxin–producing Escherichia coli (STEC), Salmonella strains, and Listeria monocytogenes, as well as on the sensory characteristics of minimally processed spinach. Spinach samples were inoculated with a cocktail of three strains each of STEC, Salmonella strains, and L. monocytogenes, separately, and were exposed to gamma radiation doses of 0, 0.2, 0.4, 0.6, 0.8, and 1.0 kGy. Samples that were exposed to 0.0, 1.0, and 1.5 kGy and kept under refrigeration (4°C) for 12 days were submitted to sensory analysis. D10-values ranged from 0.19 to 0.20 kGy for Salmonella and from 0.20 to 0.21 for L. monocytogenes; for STEC, the value was 0.17 kGy. Spinach showed good acceptability, even after exposure to 1.5 kGy. Because gamma radiation reduced the selected pathogens without causing significant changes in the quality of spinach leaves, it may be a useful method to improve safety in the fresh produce industry.

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