Dust Proof Research Articles

Hydrophobic and oleophobic nanopillars reduce viscous drag in slit nanofluidic channels

Nanofluidics exploiting 100 nm nanochannels has developed, and ultrasmall analytical applications in single-molecule level are expected. However, with downscaling the channel size, the required external pressure for driving liquids becomes exceedingly high due to increased fluid resistance and causes a problem to miniaturize a fluidic system. In the present study, we developed a drag reduction method of slit nanochannels with micrometers-width and nanometers-depth for both aqueous and organic reagents by integrating hydrophobic and oleophobic nanostructured surface. A fabrication process based on electron beam lithography and dry etching was established to realize inverted-trapezoidal shaped hydrophobically modified nanopillars with 300 nm width and 210 nm height on a fused-silica substrate. We optimized the geometry of nanopillars, and those with an upper base angle of 78° and an interval of 400 nm induced hydrophobic property for water with a contact angle of 139° and also oleophobic property for hexadecane with that of 108° by the Cassie–Baxter state with the pinning effect. By integrating the nanopillars, drag reduction of slit nanochannels for both water and hexadecane by slipping with the gas–liquid interface at the nanopillar interval was achieved with apparent slip lengths of 269 nm (water) and 108 nm (hexadecane). The drag reduction rate increased with decreasing the channel depth, and for a nanochannel with 208 nm depth, rates of 87% (water) and 80% (hexadecane) were achieved. We demonstrated miniaturization and energy saving of nanofluidic system based on the developed method. This work will greatly contribute to advancement of nanofluidics and engineering for dust proof materials.

ROLE OF NANTECHNOLOGY IN SMART PHONE

Smart phone has changed at a rapid speed since its launch. We all have experienced the change from key pad to touch screen, connecting smart phone to internet and attending online class or doing net banking transactions. Smart phone are being used for shopping online, placing orders from restaurants and also book cinema tickets or get the medicine in emergency. The velocity of change with smart phone still continues and we will experience many changes in future. The reason behind these additional features can be due to nanotechnology. Some changes can be making the smart phone water proof and dust proof .We can swim with smart phones in pocket and rains may not damage the smart phone. In addition to this smart phone may become bendable. All this changes can be due to nanotechnology. In this article we discuss how nanotechnology can contribute to smart phones.

Dust proof properties of spinodal porous surfaces.

With an aim of dust proof in optical coating, contact force with spinodal porous surfaces was investigated by counting the number of particles after exposure to a practical circumstance and by directly measuring the contact forces with a probe of Au sphere using an atomic force microscope (AFM). The interaction between the oiled particles and the porous surface was also investigated on an antireflection coating using greases containing particles of polytetrafluoroethylene (PTFE). It was found that the porous structure played the role of adsorbing oil and lowering the contact force between the particles and the surface without deterioration of the antireflection. The contact force was treated based on the liquid bridges between the particles and the surface, and the contribution from the term of Laplace pressure is inferred to be lowered due to the reduced width of the silica skeletons.

Research and analysis on the dustproof structure of low voltage switchgear

This study improves the dustproof effect by changing the appearance structure of the low voltage switchgear. The exterior structure of the low-voltage switchgear adopts S profile to prevent dust from entering the cabinet body and make dust proof treatment at the connection of the cabinet board parts. Through the dust experiment, compare the protective effect of low-voltage switchgear with common appearance structure, low-voltage switchgear with common appearance structure after dust-proof processing and the new type of structure. Finally, it is concluded that the low-voltage switchgear can effectively reduce the entry of dust by increasing the complexity of dust entry channels, and the S-shaped appearance structure can reduce more than half of the dust entering compared with the ordinary appearance structure.

Reusable Polybenzimidazole Nanofiber Membrane Filter for Highly Breathable PM2.5 Dust Proof Mask.

Ultrafine particulate matters (PMs) are an imminent threat to the human respiratory system, as their sizes are comparable to and even smaller than human tissues. To cope with this situation, researchers have developed and commercialized various personal dust proof masks. However, because of the relatively thick filter membrane to guarantee filtering efficiency, a huge pressure drop across the active filter layer is inevitable and breathing through it becomes uncomfortable. In this work, we investigated the performance of electrospun polybenzimidazole (PBI) nanofiber membrane filters that can potentially be used for dust proof masks or other high-performance filters. Thanks to its high dipole moment (6.12) as confirmed by density functional theory (DFT) calculation, the surface potential of the PBI nanofiber air filter, measured by KPFM, was higher than that of other commercially available mask filters. The filter developed in this work provides high PM filtering efficiency of ∼98.5% at much reduced pressure drop (130 Pa) in comparison to those used in commercially available masks (386 Pa) with similar filtering efficiencies. Consequently, an approximately 3-fold higher quality factor (∼0.032), evaluated for PM2.5, in comparison to that of commercial ones (∼0.011) was achieved by using PBI nanofiber. Furthermore, we developed a cleaning method effective for the filter contaminated by both inorganic and organic PMs. Even after several cycles of cleaning, the PBI filter membrane demonstrated negligible damage and retained its original performance because of its mechanical, thermal, and chemical durability.

Design Optimization of Mold for Dust Proof Cap

Design Optimization of Mold for Dust Proof Cap

A new penetration test method: protection efficiency of glove and clothing materials against diphenylmethane diisocyanate (MDI).

Reported cases of allergic contact dermatitis caused by methylenediphenyl diisocyanate (MDI) have increased and thereby increased the need for adequate skin protection. Current standardized permeation and penetration test methods give information about efficacy of protective materials against individual components of the polyurethane systems. They do not give information of what kind of clothing materials workers should wear against splashes when handling mixed MDI-polyurethane formulations, which contain MDI, its oligomers, and polyols. The aim of this study was to develop and validate a sensitive penetration test method that can be used to select clothing that is protective enough against uncured splashes of MDI-polyurethane, still easy to use, and also, to find affordable glove materials that provide adequate protection during a short contact. The penetration of MDI through eight representative glove or clothing materials was studied with the developed test procedure. One MDI hardener and two polymeric MDI (PMDI)-polyol formulations representing different curing times were used as test substances. The materials tested included work clothing (woven) fabric, arm shields (nonwoven fabric), old T-shirt, winter gloves, and gloves of nitrile rubber, leather, vinyl (PVC), and natural rubber. A drop (50 µl) of test substance was added to the outer surface of the glove/clothing material, which had Tape Fixomull attached to the inner surface as a collection medium. After penetration times of 5 or 20min, the collecting material was removed and immediately immersed into acetonitrile containing 1-(2-methoxyphenyl)-piperazine for derivatization. The formed urea derivatives of 2,4'-MDI and 4,4'-MDI were analysed using liquid chromatography with mass spectrometric and UV detection. The precision of the test method was good for the material with high penetration (work clothing fabric) of MDI, as the relative standard deviation (RSD) was 14 and 20%. For the arm shield with a low penetration (the nonwoven fabric), the precision was lower with RSDs of 35 and 50%. For two clothing materials, the penetration was high (134-577 µg cm(-2)). Low penetration (<0.5 µg cm(-2)) was shown by the arm shield and the natural rubber glove. Three glove materials showed no detectable MDI penetration (<0.002 µg cm(-2)). Two affordable glove materials (natural rubber and nitrile rubber) and one clothing material (dust proof arm shield) that can provide adequate protection during short contact with solvent free PMDI formulations were found. The new test procedure should be standardized in order to get a new international penetration standard.

208404 完全気密なクローラベルトを持つ柔軟変形移動体の開発(OS17 ロボティクス・メカトロニクス5,オーガナイズド・セッション)

A many crawler vehicles for rescue use have been researched so far. In the near future, if this type of research is to advance to the next stage, experiments in realistic environments are necessary. Particularly, dust proof and water proof capabilities are necessary to operate in a real environment. The existing sealing technology for the driving parts is difficult to be used for robots whose outputs are small because the friction loss is not small. This paper describes proposal of the high strength retractable skin and development of the closed type crawler vehicle covered by it.

Studies on the Dust Proof Faculties of Air Cleaner on Farm Eengines (Part III)

Studies on the Dust Proof Faculties of Air Cleaner on Farm Eengines (Part III)

Studies on the Dust Proof Faculties of Air Cleaner on Farm Engines (part IV)

Studies on the Dust Proof Faculties of Air Cleaner on Farm Engines (part IV)

Studies on the Dust Proof Faculties of Air Cleaner on Farm Eengines (Part III)

Studies on the Dust Proof Faculties of Air Cleaner on Farm Eengines (Part III)

Studies on the dust proof faculties of air cleaner on farm engines (II)

Studies on the dust proof faculties of air cleaner on farm engines (II)