Air purification equipment combining a filter coated by silver nanoparticles with a nano-TiO ₂ photocatalyst for use in hospitals

Abstract

X-ray diffraction, scanning electron microscopy and transmission electron microscopy showed that TiO 2 particles synthesized by a sol-gel procedure exhibited uniform size about 16-20 nm. This nanopowder was deposited on a porous quartz tube (D = 74 mm, L = 418 mm, deposit density ∼16.4 mg cm −2 ) through an intermediate adhesive polymethylmethacrylate layer to manufacture a photocatalytic filter tube. A polypropylene pre-filter was coated with a nanosilver layer (particle size ∼20 nm) prepared by aqueous molecular solution method. An air cleaner of 250 m 3 h −1 capacity equipped with this pre-filter, an electrostatic air filter, 4 photocatalytic filter tubes and 4 UV-A lamps (36 W) presented the high degradation ability for certain volatile organic compounds (VOCs), bacteria and fungi. The VOCs degradation performances of the equipment with respect to divers compounds are different: in a 10 m 3 box, 91.6% of butanol was removed within 55 min, 80% of acetone within 100 min, 70.1% of diethyl ether within 120 min and only 43% of benzene was oxidized within 150 min. Over 99% of bacteria and fungi were killed after the air passage through the equipment. For application, it was placed in the intensive care room (volume of 125 m 3 ) of E hospital in Hanoi; 69% of bacteria and 63% of fungi were killed within 6 h.

Viral Diagnostics and Preventive Techniques in the Era of COVID-19: Role of Nanoparticles

“…SiO 2 -Ag NPs coated antiviral air filters with a coating density higher than 2.0 × 10 8 cm 2 were reported to reduce the viral infection by 99.9% (Joe et al, 2014). AgNPs-coated filters with nano-TiO 2 were established as an advanced air purifying system in hospitals (Le et al, 2015). A hybrid composite comprising AgNPs and CNTs synthesized using aerosol nebulization and thermal evaporation/condensation processes were used as antimicrobial air filter (Jung et al, 2011).…”

Light‐Permeable Air Filter with Self‐Polarized Nylon‐11 Nanofibers for Enhanced Trapping of Particulate Matters

“…Hence, various PM trapping methods have been proposed to date. The typical and widely used method of capturing PMs is by passing the air containing PMs through a filter by forced air circulation; this method requires additional equipment or system . Thus, it would be beneficial to develop an air filter that can trap PMs under a natural ventilation condition.…”

Coating of Polyetheretherketone Films with Silver Nanoparticles by a Simple Chemical Reduction Method and Their Antibacterial Activity

“…Among the bacteria that are found in the environment and are scattered by air purifying equipment are Escherichia coli, Bacillus subtilis, Staphylococcus aureus and others such as Serratia marcescens that cause diseases such as gastroenteritis, urinary tract infections, meningitis and brain abscesses, in addition to pathogenic bacteria that also affect plants and cause cell death such as Bacillus licheniformis [4,5]. The alternative to this problem for a long time, has been the combination of air-purifying equipment filters with nanocoatings that inhibit bacterial growth, using various polymeric materials such as polyimide, polyurethane, polyacrylonitrile and polysulfone, which has generated contamination and low resistance to exposure of the various environmental effects [6,7]. For this reason, one of the polymers that promises to be efficient as a multifunctional material in the design of filters of air purification equipments is polyetheretherketone (PEEK).…”