scholarly journals Large-Scale Preparation of Polymer Nanofibers for Air Filtration by a New Multineedle Electrospinning Device

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Yuan Xu ◽  
Xiao Li ◽  
Hong-Fei Xiang ◽  
Qian-Qian Zhang ◽  
Xiao-Xiong Wang ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Large Scale ◽  
Gas Permeability ◽  
Thermoplastic Polyurethane ◽  
Mass Scale ◽  
Scale Production ◽  
Air Filtration ◽  
Polymer Nanofibers ◽  
Water Contact ◽  
New Device

There are still some challenges for mass-scale production via electrospinning (e-spinning). For example, the cost of industrialized equipment is relatively expensive, and the subsequent maintenance costs are high. The reliability and stability of the production process are also one of the important challenges. The recycling of organic solvents and the volatilization of solvents not only affect the quality of nanofibers, but also causes environmental pollution. In this work, a new multineedle e-spinning device has been proposed for large-scale production of polymer nanofibers. The spinning solution is provided through the outside surface of the needle to avoid needle clogging problem, which is different from the traditional multineedle e-spinning. The successful preparation of thermoplastic polyurethane (TPU) nanofiber membrane with production rate ~50 g h-1 proves the feasibility of the device, which also can be used to prepare other functional nanofibers such as polyvinylidene fluoride (PVDF) and polyacrylonitrile (PAN). The prepared TPU nanofiber gauze has been characterized. The average fiber diameter was 145.3 nm. The surface of the sample was found to be uniform, and the water contact angle was 138.9°. The sample had gas permeability of 1500 mm s-1, excellent PM2.5 removal efficiency of 99.897%, and optical transparency of ~56%, indicating that the new device has a practical application perspective.

scholarly journals Mycosinthetized Ag, CuO and ZnO nanoparticles from a promising Trichoderma harzianum strain and their antifungal potential against important phytopathogens

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Verónica Fabiana Consolo ◽  
Andrés Torres-Nicolini ◽  
Vera Alejandra Alvarez
Keyword(s):  
Zno Nanoparticles ◽  
Trichoderma Harzianum ◽  
Large Scale ◽  
Mass Scale ◽  
Scale Production ◽  
Dependent Manner ◽  
Zno Nps ◽  
Extracellular Biosynthesis ◽  
Cuo Nps ◽  
Fungal Phytopathogens

AbstractFungal green biosynthesis of nanoparticles (NPs) is a promising eco-friendly method for mass-scale production. In the present study Ag, CuO and ZnO nanoparticles were biogenically synthetized using a cell filtrate of a strain of Trichoderma harzianum as a reducer and stabilizer agent. The structure, morphology and physicochemical properties of the NPs were characterized through transmission electron microscopy, dynamic light scattering, wide angle X-ray scattering and thermogravimetric analysis. Since nanotechnology could offer promising applications in agricultural area, we evaluated the ability of the NPs to reduce the growth of important fungal phytopathogens as Alternaria alternata, Pyricularia oryzae and Sclerotinia sclerotiorum. Silver and CuO NPs reduced significantly the mycelial growth of A. alternata and P. oryzae in a dose dependent manner. This is the first report of a multiple extracellular biosynthesis of NPs from T. harzianum and the first time that CuO and ZnO NPs were obtained from this fungus. In addition, we highlighted the rapid production of NPs, as well as, the potential of Ag and CuO for the control of phytopathogens. On the other hand, the three types of NPs could be easily and sustainably produced on a large scale with the chance of having multiple applications in biotechnological processes.

Preparation of Strongly Hydrophobic Film with Large Area and Flexibility Based on Micro Fabrication

2015 ◽  
Vol 645-646 ◽  
pp. 195-200
Author(s):  
Yi Bo Zeng ◽  
Ting Ting Wang ◽  
Jian Yan Wang ◽  
Hang Guo
Keyword(s):  
Silicon Wafer ◽  
Polyvinylidene Fluoride ◽  
Large Scale ◽  
Composite Layer ◽  
Scale Production ◽  
Micro Channel ◽  
Large Area ◽  
Micro Fabrication ◽  
Chemical Grafting ◽  
Micro Molding

In order to gain strongly hydrophobic film with large area and flexibility conveniently and effectively, how to prepare film with combination of technologies including micro fabrication, chemical grafting and micro molding is discussed. Firstly, micro channel arrays that the width is 5μm on the silicon wafer are prepared by micro fabrication. Then after spraying PVDF (Polyvinylidene Fluoride) lotion and pouring PDMS (Polydimethylsiloxane) glue solution onto the silicon wafer as the mould successively, the mixture need to be precured, which constructs rough structures in micro and nanoscale on the low surface energy film. Finally chemical grafting for film is carried out under the condition of O2 and 130°C so that the modification layer easy to adhesive on the boundary between PVDF and PDMS can be formed. Through the above technical routes, the strongly hydrophobic film that the general contact angle exceeds above 145o, the area is 180mm×64mm, the thickness is 0.9mm and the composite layer is firmly combined is gained. Compared to other hydrophobic materials the film is available in large area and has an advantage of flexibility. Meanwhile, the way that the film prepared by micro molding and in virtue of the silicon wafer with micro channel arrays as the mould contributes to large scale production.

scholarly journals Environmental Impacts of Distributed Manufacturing from 3-D Printing of Polymer Components and Products

2013 ◽  
Vol 1492 ◽  
pp. 85-90 ◽  
Author(s):  
Megan Kreiger ◽  
Joshua M. Pearce
Keyword(s):  
Environmental Impact ◽  
Open Source ◽  
Large Scale ◽  
Low Cost ◽  
Acrylonitrile Butadiene Styrene ◽  
Mass Scale ◽  
Embodied Energy ◽  
Scale Production ◽  
Distributed Manufacturing ◽  
And Performance

ABSTRACTAlthough additive layer manufacturing is well established for rapid prototyping the low throughput and historic costs have prevented mass-scale adoption. The recent development of the RepRap, an open source self-replicating rapid prototyper, has made low-cost 3-D printers readily available to the public at reasonable prices (<$1,000). The RepRap (Prusa Mendell variant) currently prints 3-D objects in a 200x200x140 square millimeters build envelope from acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA). ABS and PLA are both thermoplastics that can be injection-molded, each with their own benefits, as ABS is rigid and durable, while PLA is plant-based and can be recycled and composted. The melting temperature of ABS and PLA enable use in low-cost 3-D printers, as these temperature are low enough to use in melt extrusion in the home, while high enough for prints to retain their shape at average use temperatures. Using 3-D printers to manufacture provides the ability to both change the fill composition by printing voids and fabricate shapes that are impossible to make using tradition methods like injection molding. This allows more complicated shapes to be created while using less material, which could reduce environmental impact.As the open source 3-D printers continue to evolve and improve in both cost and performance, the potential for economically-viable distributed manufacturing of products increases. Thus, products and components could be customized and printed on-site by individual consumers as needed, reversing the historical trend towards centrally mass-manufactured and shipped products. Distributed manufacturing reduces embodied transportation energy from the distribution of conventional centralized manufacturing, but questions remain concerning the potential for increases in the overall embodied energy of the manufacturing due to reduction in scale. In order to quantify the environmental impact of distributed manufacturing using 3-D printers, a life cycle analysis was performed on a plastic juicer. The energy consumed and emissions produced from conventional large-scale production overseas are compared to experimental measurements on a RepRap producing identical products with ABS and PLA. The results of this LCA are discussed in relation to the environmental impact of distributed manufacturing with 3-D printers and polymer selection for 3-D printing to reduce this impact. The results of this study show that distributed manufacturing uses less energy than conventional manufacturing due to the RepRap's unique ability to reduce fill composition. Distributed manufacturing also has less emissions than conventional manufacturing when using PLA and when using ABS with solar photovoltaic power. The results of this study indicate that open-source additive layer distributed manufacturing is both technically viable and beneficial from an ecological perspective.

Fabrication of Superhydrophobic Surfaces on Copper Substrates via Brush Plating Technique

2013 ◽  
Vol 834-836 ◽  
pp. 662-669 ◽  
Author(s):  
Ke Hu ◽  
Quan Xin Xu ◽  
Xiao Long Yang
Keyword(s):  
Large Scale ◽  
Superhydrophobic Surfaces ◽  
Scale Production ◽  
Sliding Angle ◽  
Water Contact ◽  
Copper Surfaces ◽  
Plating Technique ◽  
Large Scale Production ◽  
Sample Technique ◽  
Brush Plating

Superhydrophobic surfaces on metal substrates are often prepared via roughing the surfaces and lowering their surface energy. Composite brush plating technique is developed to prepare superhydrophobic n-SiO2/Ni brush plating composite coating on copper surfaces. Under the better process parameters, the water contact angle of the obtained superhydrophobic surface is approximately 160°, and the water sliding angle is less than 10°. The influences of plating voltage and plating time on the coating surface structure and hydrophobicity were discussed. The surface morphology and chemical composition were characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS).The results show that the prepared surfaces have the appearance of the uniform micron papilla-like structures, which are composed of submicron globular Ni particles covered with n-SiO2nanoscale villiform structures. These hierarchical micro/nanostructures are similar to the lotus leaf and play an important role in gaining superhydrophobicity. It is expected that this sample technique will be widely used for large-scale production of superhydrophobic engineering materials.

scholarly journals Incorporation of PVDF Nanofibre Multilayers into Functional Structure for Filtration Applications

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 771 ◽  
Author(s):  
Remi Roche ◽  
Fatma Yalcinkaya
Keyword(s):  
Polyvinylidene Fluoride ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Water Filtration ◽  
Size Analysis ◽  
Air Filtration ◽  
Water Contact ◽  
Pore Size Analysis ◽  
Lamination Process ◽  
Temperature Force

Membranes are considered as a promising technology for separation and filtration processes. Here, novel polyvinylidene fluoride (PVDF) nanofibrous multilayer membranes were fabricated by wire-based industrial electrospinning equipment following by a lamination process. The lamination process was optimised under various applied temperature, force of lamination, and lamination time. Air permeability and burst-pressure tests were run to determine the optimum membranes for filtration application. The structures of the prepared membranes were characterised by scanning electron microscopy and pore-size analysis. The hydrophilic properties of the membranes were evaluated using water contact angle measurement, and the mechanical strength of the membranes was analysed. Air and water filtration tests were run to find the possible application of prepared membranes. The air filtration results showed that membranes had high filtration efficiencies: Over 99.00% for PM2.5, and PM0.1. The water filtration results indicated that permeability of the membranes changed from 288 to 3275 L/m2hbar. The successful preparation of such an interesting material may provide a new approach for the design and development of electrospun filter membranes.

scholarly journals Functionalization of hydrophobic nonwoven cotton fabric for oil and water repellency

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Pran Krisna Saha ◽  
Rony Mia ◽  
Yang Zhou ◽  
Taosif Ahmed
Keyword(s):  
Cotton Fabric ◽  
Large Scale ◽  
High Efficiency ◽  
Low Cost ◽  
Water Repellency ◽  
Scale Production ◽  
Hydrophobic Surfaces ◽  
Water Contact ◽  
Simple Method ◽  
Remarkable Feature

AbstractHighly hydrophobic surfaces exhibit a remarkable feature in the repellency of oil and water. However, the relatively complex preparation process, high costs, and harmful compounds have largely limited their applications. This research aim is to fabricate hydrophobic nonwoven fabrics with low-cost and nontoxic materials. Despite various wettable materials, nonwoven cotton fabric material bearing hydrophobic surfaces has been received significant attention. This is mainly owing to its easy handling, high flexibility, environment friendly, low cost, biodegradability, high efficiency, and easily scalable fabrication. In this study, a simple chemical modification method using hexadecyltrimethoxysilane (HDTMS) with ethanol which is a better method in comparison with other methods since it is an inexpensive, simple method, and offers an easy adjustment of chemical composition required for a surface to show hydrophobic behaviors. The wetting behavior of cotton samples was investigated by water contact angle measurement. The best result comes from 2 ml HDTMS with 40 ml ethanol at 60 °C. The result shows that the treated cotton fabrics exhibited excellent chemical stability and outstanding non-wettability with the WCA of 126 ± 2°. It also shows that standard oil and water repellency, which offers an opportunity to accelerate the large-scale production of hydrophobic textile materials for new industrial applications. Graphic abstract

Large-scale production ofPlasmodium vivaxsporozoites

Parasitology ◽  
1990 ◽  
Vol 101 (3) ◽  
pp. 317-320 ◽  
Author(s):  
T. Ponnudurai ◽  
A. H. W. Lensen ◽  
G. J. van Gemert ◽  
M. Bolmer ◽  
A. van Belkum ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Pan Troglodytes ◽  
Large Scale ◽  
Anopheles Stephensi ◽  
Mass Scale ◽  
Mixed Infections ◽  
Scale Production ◽  
Large Scale Production ◽  
Membrane Feeding ◽  
Mass Scale Production

SUMMARYMass-scale production ofPlasmodium vivaxsporozoites inAnopheles stephensiwas achieved using the chimpanzee (Pan troglodytes) as a source of infective blood. Membrane feeding was as successful as feeding mosquitoes directly on the animal so long as the time between drawing the blood and feeding was restricted to 45 min. Longer delays such as 2–3 h resulted in loss of infectivity in terms of oocyst production. The selected strain ofA. stephensiwas highly susceptible toP. vivax(Chesson strain). A strain ofA. stephensirelatively refractory toP. falciparumshowed no cross-refractoriness toP. vivax. Mixed infections ofP. falciparumandP. vivaxdid not interfere with each other in their development inA. stephensi. A second normal blood meal to mosquitoes infected withP. vivaxincreased the yield of salivary gland sporozoites.

scholarly journals A Highly Porous Nonwoven Thermoplastic Polyurethane/Polypropylene-Based Triboelectric Nanogenerator for Energy Harvesting by Human Walking

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1044
Author(s):  
Hyun Ju Oh ◽  
Jong Hyuk Bae ◽  
Young Ki Park ◽  
Jinkyu Song ◽  
Do Kun Kim ◽  
...  
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Thermoplastic Polyurethane ◽  
Human Walking ◽  
Triboelectric Nanogenerator ◽  
Maximum Output ◽  
Scale Production ◽  
Conversion Performance ◽  
Nonwoven Fiber ◽  
Highly Porous

: A highly porous nonwoven thermoplastic polyurethane (TPU)/Polypropylene (PP) triboelectric nanogenerator (N-TENG) was developed. To fabricate the triboelectric layers, the TPU nanofiber was directly electrospun onto the nonwoven PP at different basis weights (15, 30, and 50 g/m2). The surface morphologies and porosities of the nonwoven PP and TPU nanofiber mats were characterized by field-emission scanning electron microscopy and porosimetry. The triboelectric performance of the nonwoven TPU/PP based TENG was found to improve with an increase in the basis weight of nonwoven PP. The maximum output voltage and current of the TPU/PP N-TENG with 50% PP basis weight reached 110.18 ± 6.06 V and 7.28 ± 0.67 µA, respectively, due to high air volume of nonwoven without spacers. In order to demonstrate its practical application as a generator, a TPU/PP N-TENG-attached insole for footwear was fabricated. The N-TENG was used as a power source to turn on 57 light-emitting diodes through human-walking, without any charging system. Thus, owing to its excellent energy-conversion performance, simple fabrication process, and low cost, the breathable and wearable nonwoven fiber-based TENG is suitable for large-scale production, to be used in wearable devices.

Facile thermoplastic polyurethane-based multi-walled carbon nanotube ink for fabrication of screen-printed fabric electrodes of wearable e-textiles with high adhesion and resistance stability under large deformation

2021 ◽  
pp. 004051752110086
Author(s):  
Lihong Jiang ◽  
Hong Hong ◽  
Jiyong Hu
Keyword(s):  
Carbon Nanotubes ◽  
Large Deformation ◽  
Large Scale ◽  
Thermoplastic Polyurethane ◽  
Scale Production ◽  
Conductive Ink ◽  
Conductive Inks ◽  
High Adhesion ◽  
Resistance Stability ◽  
Screen Printed

Carbon nanotubes have been widely used to formulate printed conductive ink in recent years due to their excellent conductivity, chemical stability and mechanical properties. However, the common problems of this ink, such as poor adhesion and low resistance stability under large deformation, hinder its application in the fabric electrodes (FEs) of wearable and stretchable e-textiles. Herein, conductive inks with a simple preparation process, high adhesion and conductive stability were formulated by mixing the conductive filler, multi-walled carbon nanotubes (MWCNTs), into a thermoplastic polyurethane matrix with a reversible cross-linked structure. Then it is evaluated whether the MWCNT-based conductive ink is suitable for the screen-printing fabrication of highly durable and washable FEs. The experimental results showed that the screen-printed fabric electrode exhibited remarkable resistance stability under bending and folding deformation. In particular, after 1000 bending cycles and 100 folding–unfolding cycles under additional pressure, the sheet resistance of FEs only increased by 0.8% and 5.0%, respectively. Moreover, the screen-printed conductive pattern has strong adhesion to polyamide fabric substrate by the Scotch tape and washing tests, and there are no significant changes in resistance and surface morphology. High-performance conductive inks with facile and large-scale production potential are developed, and show great prospect in the development of wearable printing e-textiles.

AGRICULTURAL PRODUCTION OF CA DONG PEOPLE IN RESETTLEMENT AREA OF TRANH RIVER HYDROPOWER NUMBER 2: CURRENT SITUATION AND IMPACT FACTORS

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Bùi Thị Bích Lan
Keyword(s):  
Social Relations ◽  
Agricultural Production ◽  
Large Scale ◽  
Transition Process ◽  
Impact Factors ◽  
Small Scale ◽  
Scale Production ◽  
Technical Application ◽  
Production Models ◽  
Role Of The State

In Vietnam, the construction of hydropower projects has contributed significantly in the cause of industrialization and modernization of the country. The place where hydropower projects are built is mostly inhabited by ethnic minorities - communities that rely primarily on land, a very important source of livelihood security. In the context of the lack of common productive land in resettlement areas, the orientation for agricultural production is to promote indigenous knowledge combined with increasing scientific and technical application; shifting from small-scale production practices to large-scale commodity production. However, the research results of this article show that many obstacles in the transition process are being posed such as limitations on natural resources, traditional production thinking or the suitability and effectiveness of scientific - technical application models. When agricultural production does not ensure food security, a number of implications for people’s lives are increasingly evident, such as poverty, preserving cultural identity, social relations and resource protection. Since then, it has set the role of the State in researching and building appropriate agricultural production models to exploit local strengths and ensure sustainability.

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