scholarly journals Preparation and Properties of sc-PLA/PMMA Transparent Nanofiber Air Filter

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 996 ◽  
Author(s):  
Shengnan Lv ◽  
Xin Zhao ◽  
Lei Shi ◽  
Gaokai Zhang ◽  
Shubo Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Indoor Air ◽  
Cross Linking ◽  
Environment And Public Health ◽  
Air Filters ◽  
Air Filter ◽  
Electrostatic Induction ◽  
Air Resistance ◽  
Pm Removal

Particulate matter (PM) pollution is a serious concern for the environment and public health. To protect indoor air quality, nanofiber filters have been used to coat window screens due to their high PM removal efficiency, transparency and low air resistance. However, these materials have poor mechanical property. In this study, electrostatic induction-assisted solution blowing was used to fabricate polylactide stereocomplex (sc-PLA), which served as reinforcement to enhance the physical cross-linking point to significantly restrict poly(methyl methacrylate) (PMMA) molecular chain motion and improve the mechanical properties of sc-PLA/PMMA nanofibers. Moreover, the introduction of sc-PLA led to the formation of thick/thin composite nanofiber structure, which is beneficial for the mechanical property. Thus, sc-PLA/PMMA air filters of ~83% transparency with 99.5% PM2.5 removal and 140% increase in mechanical properties were achieved when 5 wt % sc-PLA was added to PMMA. Hence, the addition of sc-PLA to transparent filters can effectively improve their performance.

scholarly journals Embryo movements regulate tendon mechanical property development

2018 ◽  
Vol 373 (1759) ◽  
pp. 20170325 ◽  
Author(s):  
Xuan Sabrina Pan ◽  
Jiewen Li ◽  
Edward B. Brown ◽  
Catherine K. Kuo
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Current Knowledge ◽  
Lysyl Oxidase ◽  
Cross Linking ◽  
Activity Levels ◽  
Property Development ◽  
Calcaneal Tendon ◽  
Movement Frequency ◽  
Chick Embryo Model

Tendons transmit forces from muscles to bones to enable skeletal motility. During development, tendons begin to bear load at the onset of embryo movements. Using the chick embryo model, this study showed that altered embryo movement frequency led to changes in elastic modulus of calcaneal tendon. In particular, paralysis led to decreased modulus, whereas hypermotility led to increased modulus. Paralysis also led to reductions in activity levels of lysyl oxidase (LOX), an enzyme that we previously showed is required for cross-linking-mediated elaboration of tendon mechanical properties. Additionally, inhibition of LOX activity abrogated hypermotility-induced increases in modulus. Taken together, our findings suggest embryo movements are critical for tendon mechanical property development and implicate LOX in this process. These exciting findings expand current knowledge of how functional tendons form during development and could guide future clinical approaches to treat tendon defects associated with abnormal mechanical loading in utero . This article is part of the Theo Murphy meeting issue ‘Mechanics of development’.

Study on Irradiation Cross-Linking Modification and Biodegradability of Poly (Butylene Succinate)

2015 ◽  
Vol 1089 ◽  
pp. 172-177
Author(s):  
Hui Liu ◽  
Qiang Li ◽  
Cheng Zhi Chuai ◽  
Zhe Wang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Weight Loss ◽  
Loss Rate ◽  
Cross Linking ◽  
Weight Loss Rate ◽  
Butylene Succinate ◽  
Melt Strength ◽  
Biodegradable Properties

The pure PBS material has been taken irradiation cross-linking modification in order to improve the melt strength of PBS. The mechanical properties, sanitation performance and biodegradable properties of the modified PBS were investigated. The results showed that the modified PBS has fine hygiene performance. The mechanical property increased, but it reduced rapidly after put into the specific soil. The weight loss rate of PBS reached 50.86% after degradation in humus for 56 days.

scholarly journals PVP-Assisted Shellac Nanofiber Membrane as Highly Efficient, Eco-Friendly, Translucent Air Filter

2021 ◽  
Vol 11 (23) ◽  
pp. 11094
Author(s):  
Shanshuai Lu ◽  
Congling Li ◽  
Rui Liu ◽  
Aifeng Lv
Keyword(s):  
Mechanical Properties ◽  
Low Cost ◽  
Light Transmittance ◽  
Liquid Droplets ◽  
Air Filtration ◽  
Nanofiber Membrane ◽  
Air Filters ◽  
Air Filter ◽  
Highly Efficient ◽  
Pm2.5 And Pm10

Particulate matter (PM), composed of tiny solids and liquid droplets in polluted air, poses a serious threat to human health. Traditional air filters usually cause secondary pollution due to their poor degradability. Here, shellac, as an environmentally friendly natural organic material, was successfully applied to fabricate biodegradable air filters. Since pure shellac fiber shows poor mechanical properties and bad light transmittance, we then introduced a small amount of polyvinylpyrrolidone (PVP) in the shellac solution to prepare highly efficient air filter membranes by the electrospinning method. The prepared PVP-assisted shellac nanofiber membrane (P-Shellac FME) demonstrated improved filtration efficiencies as high as 95% and 98% for PM2.5 and PM10, respectively. The P-Shellac FME also showed good stability, with filtration efficiencies still above 90% and 95% for PM2.5 and PM10 even after six hours of air filtering under high PM concentrations. The pressure drop going through the filter was only 101 Pa, which is also comparable to the value of 76 Pa obtained using commercial polypropylene nanofibers (PP nanofibers, peeled off from the surgical mask), indicating good air permeability of P-Shellac FME. Additionally, P-Shellac FME also showed the advantages of translucence, biodegradability, improved mechanical properties, and low cost. We believe that the P-Shellac FME will make a significant contribution in the application of air filtration.

A critical review on cleanroom filtration

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Monica Puri Sikka ◽  
Mandira Mondal
Keyword(s):  
Air Quality ◽  
Indoor Air ◽  
Air Pollutants ◽  
Filter Medium ◽  
Future Research ◽  
Filter Media ◽  
Air Filters ◽  
Air Filter ◽  
Content Type ◽  
High Durability

Purpose Cleanrooms are highly controlled enclosed rooms where air quality is monitored and ensured to have less contamination according to standard cleanliness level. Air filters are used to optimize indoor air quality and remove air pollutants. Filter media and filtering system are decided as per requirement. Depth filter media are mostly used in cleanroom filtrations. This paper aims to present a comprehensive review of the evolution of cleanroom filter media. It evaluates the advantages and disadvantages of air filter media. It is also studied which air filters have additional properties such as anti-microbial properties, anti-odour properties and chemical absorbent. Development and innovation of air filters and filtration techniques are necessary to improve the performance via the synergistic effect and it can be a possible avenue of future research. Design/methodology/approach This paper aims to drive the future of air filter research and development in achieving high-performance filtration with high filtration efficiency, low operational cost and high durability. Air pollutants are classified into three types: suspended particles, volatile organic pollutants and microorganisms. Technologies involved in purification are filtration, water washing purification, electrostatic precipitation and anion technology. They purify the air by running it through a filter medium that traps dust, hair, pet fur and debris. As air passes through the filter media, they function as a sieve, capturing particles. The fibres in the filter medium provide a winding path for airflow. There are different types of air filters such as the high-efficiency particulate air filter, fibreglass air filter and ultra-low particulate air filter. Findings Emerging filtration technologies and filters such as nanofibres, filters with polytetrafluoroethylene membrane are likely to become prevalent over the coming years globally. The introduction of indoor air filtration with thermal comfort can be a possible avenue of future research along with expanding indoor environment monitoring and improving air quality predictions. New air filters and filtration technologies having better performance with low cost and high durability must be developed which can restrict multiple types of pollutants at the same time. Originality/value The systematic literature review approach used in this paper highlights the emerging trends and issues in cleanroom filtration in a structured and thematic manner, enabling future work to progress as it will continue to develop and evolve.

scholarly journals Should homes and workplaces purchase portable air filters to reduce the transmission of SARS-CoV-2 and other respiratory infections? A systematic review

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0251049
Author(s):  
Ashley Hammond ◽  
Tanzeela Khalid ◽  
Hannah V. Thornton ◽  
Claire A. Woodall ◽  
Alastair D. Hay
Keyword(s):  
Indoor Air ◽  
High Efficiency ◽  
Respiratory Infections ◽  
Bacterial Load ◽  
Airborne Bacteria ◽  
Air Filters ◽  
Air Filter ◽  
Healthcare Settings ◽  
Randomised Controlled ◽  
Almost All

Respiratory infections, including SARS-CoV-2, are spread via inhalation or ingestion of airborne pathogens. Airborne transmission is difficult to control, particularly indoors. Manufacturers of high efficiency particulate air (HEPA) filters claim they remove almost all small particles including airborne bacteria and viruses. This study investigates whether modern portable, commercially available air filters reduce the incidence of respiratory infections and/or remove bacteria and viruses from indoor air. We systematically searched Medline, Embase and Cochrane for studies published between January 2000 and September 2020. Studies were eligible for inclusion if they included a portable, commercially available air filter in any indoor setting including care homes, schools or healthcare settings, investigating either associations with incidence of respiratory infections or removal and/or capture of aerosolised bacteria and viruses from the air within the filters. Dual data screening and extraction with narrative synthesis. No studies were found investigating the effects of air filters on the incidence of respiratory infections. Two studies investigated bacterial capture within filters and bacterial load in indoor air. One reported higher numbers of viable bacteria in the HEPA filter than in floor dust samples. The other reported HEPA filtration combined with ultraviolet light reduced bacterial load in the air by 41% (sampling time not reported). Neither paper investigated effects on viruses. There is an important absence of evidence regarding the effectiveness of a potentially cost-efficient intervention for indoor transmission of respiratory infections, including SARS-CoV-2. Two studies provide ‘proof of principle’ that air filters can capture airborne bacteria in an indoor setting. Randomised controlled trials are urgently needed to investigate effects of portable HEPA filters on incidence of respiratory infections.

scholarly journals EFFECT OF CROSSLINKING TO THE MECHANICAL PROPERTY OF APATITE GELATIN HYBRID FOR BONE SUBSTITUTION PURPOSES

2011 ◽  
Vol 11 (3) ◽  
pp. 267-272 ◽  
Author(s):  
Sunarso Sunarso ◽  
Sutarno Sutarno ◽  
Kanji Tsuru ◽  
Ika Dewi Ana ◽  
Kunio Ishikawa
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Bone Substitute ◽  
Clinical Success ◽  
Physical Property ◽  
Peptide Bond ◽  
Cross Linking ◽  
Current Generation ◽  
Synthetic Bone ◽  
Synthetic Bone Substitute

The clinical success of current generation of synthetic bone substitute relies on bio-inspired design which has a performance level close to that of natural one. In this context, biomedical approaches are considered very important to result bio-functional hybrid for bone substitution purposes. In this study, effect of cross-linking to the mechanical properties of apatite gelatin hybrid has been investigated. Cross-linking was employed by 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC) agent. The EDC agent creates a peptide bond between gelatin molecules inside the hybrid to the cross-linked structure. Cross-linked structure of gelatin increases physical property of the hybrid since it can hold the outer forces longer than that of without cross-linking.

Mechanical Property Studies on Flax Fiber Reinforced Basalt Powder Filled Polyester Composite

2020 ◽  
Vol 13 ◽  
Author(s):  
V. Arumugaprabu ◽  
K.Arun Prasath ◽  
S. Mangaleswaran ◽  
M. Manikanda Raja ◽  
R. Jegan
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Natural Fiber ◽  
Tensile Load ◽  
Flax Fiber ◽  
Flexural Properties ◽  
Weight Percentage ◽  
Tensile Impact ◽  
Polyester Composite ◽  
Additional Support

: The objective of this research is to evaluate the tensile, impact and flexural properties of flax fiber and basalt powder filled polyester composite. Flax fiber is one of the predominant reinforcement natural fiber which possess good mechanical properties and addition of basalt powder as a filler provides additional support to the composite. The Composites are prepared using flax fiber arranged in 10 layers with varying weight percentage of the basalt powder as 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.% and 30 wt.% respectively. From the results it is inferred that the composite combination 10 Layers of flax / 5 wt.%, basalt Powder absorbs more tensile load of 145 MPa. Also, for the same combination maximum flexural strength is about 60 MPa. Interestingly in the case of impact strength more energy was absorbed by 10 layers of flax and 30 wt.% of basalt powder. In addition, the failure mechanism of the composites also discussed briefly using SEM studies.

scholarly journals Air filtration improvement of konjac glucomannan-based aerogel air filters through physical structure design

2021 ◽  
Author(s):  
Hong Qian ◽  
Ying Fang ◽  
Kao Wu ◽  
Hao Wang ◽  
Bin Li ◽  
...  
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Physical Structure ◽  
Structure Design ◽  
Air Filtration ◽  
Air Filters ◽  
Air Filter ◽  
Purification Time

Abstract This study presents two methods to improve the air filtration performance of konjac glucomannan (KGM)-based aerogel air filters through physical structure design by changing the pore-size distribution and the surface area, using an air purifier. Results indicated that KGM-based aerogels had a comparable filtration effect with the commercial air filter with a longer purification time. This purification time could be shortened by over 50%, by changing the pore-size distribution from large size to small size or increase the surface area with the fold structure. This should boost the development of polysaccharide-based aerogel used as the air filter.

scholarly journals Eco-Friendly Poly(Vinyl Alcohol) Nanofiber-Based Air Filter for Effectively Capturing Particulate Matter

2021 ◽  
Vol 11 (9) ◽  
pp. 3831
Author(s):  
Han-Jung Kim ◽  
Dong-In Choi ◽  
Sang-Keun Sung ◽  
Su-Han Lee ◽  
Sang-Jin Kim ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Quality Factor ◽  
Vinyl Alcohol ◽  
Nonwoven Fabric ◽  
Poly Vinyl Alcohol ◽  
Contamination Level ◽  
Plastic Pollution ◽  
Air Filters ◽  
Air Filter ◽  
Filter Surface

Due to the increasing use of polypropylene-based nonwoven dust masks and air filters, environmental problems that occur due to the plastic pollution resulting from the disposal of these materials have also increased. Hence, an eco-friendly air filter based on PVA nanofibers (NFs) was fabricated by electrospinning on a nonwoven fabric, and its performance was evaluated as a filter capable of blocking or capturing particulate matter. The quality factor of the optimized PVA NF-based air filter was found to be 0.010606 Pa−1, which is lower than that of a HEPA filter (0.015394 Pa−1), but higher than that of a cabin air filter (0.010517 Pa−1) and a dust mask (0.009102 Pa−1). The contamination level of the PVA NF-based filter was analyzed by optical and structural analyses of the filter surface. Finally, the filter was soaked in water to selectively remove the contaminated PVA NF layer, and the remaining nonwoven fabric was able to be reused to make the filter.

scholarly journals Regulating Effect of Cement Accelerator on High Content Solid-Wastes Autoclaved Aerated Concrete (HCS-AAC) Slurry Performance and Subsequent Influence

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 799
Author(s):  
Dingkun Xie ◽  
Lixiong Cai ◽  
Jie Wang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Solid Wastes ◽  
Hydration Products ◽  
Promoting Effect ◽  
Adverse Side Effects ◽  
Foaming Process ◽  
Carbide Slag ◽  
Negative Effect ◽  
Aerated Concrete

Adverse side-effects occurred in slurry foaming and thickening process when carbide slag was substituted for quicklime in HCS-AAC. Cement accelerators were introduced to modify the slurry foaming and coagulating process during pre-curing. Meanwhile, the affiliated effects on the physical-mechanical properties and hydration products were discussed to evaluate the applicability and influence of the cement accelerator. The hydration products were characterized by mineralogical (XRD) and thermal analysis (DSC-TG). The results indicated that substituting carbide slag for quicklime retarded slurry foaming and curing progress; meanwhile, the induced mechanical property declination had a negative effect on the generation of C–S–H (I) and tobermorite. Na2SO4 and Na2O·2.0SiO2 can effectively accelerate the slurry foaming rate, but the promoting effect on slurry thickening was inconspicuous. The compressive strength of HCS-AAC obviously declined with increasing cement coagulant content, which was mainly ascribed to the decrease in bulk density caused by the accelerating effect on the slurry foaming process. Dosing Na2SO4 under 0.4% has little effect on the generation of strength contributing to hydration products while the addition of Na2O·2.0SiO2 can accelerate the generation and crystallization of C–S–H, which contributed to the high activity gelatinous SiO2 generated from the reaction between Na2O·2.0SiO2 and Ca(OH)2.

Sign in / Sign up

Export Citation Format

Share Document