Application of photocatalytic paint for destruction of benzo[a]pyrene. Impact of air humidity

2017 ◽  
Vol 20 (1) ◽  
Author(s):  
Piotr Homa ◽  
Beata Tryba
Keyword(s):  
Contact Angle ◽  
Relative Humidity ◽  
Environmental Conditions ◽  
Decomposition Rate ◽  
Uv Light ◽  
Photocatalytic Decomposition ◽  
Fluorescent Lamp ◽  
Air Humidity ◽  
Water Contact ◽  
Higher Temperature

AbstractLatex (LX) paint was tested for photocatalytic decomposition of benzo[a]pyrene (BaP) under different conditions of relative humidity (RH), temperature and irradiation. Porcelain trays coated with LX paint were loaded with BaP solution, which was dissolved in acetonitrile. Trays were placed inside the photoreactor and irradiated with UV or a fluorescent lamp. Different conditions of RH and temperature inside the photoreactor were used. BaP preliminarily adsorbed on LX paint surface was decomposed faster at higher temperature and lower RH. For example, at 42 °C and RH 20 % BaP decomposition rate reached 64 %. At same temperature and with RH of 80 % this rate decreased to only 42 %. It was also demonstrated that at high RH (80 %) and under UV irradiation water contact angle on the paint surface was decreasing at a lower rate than under RH of 20 %. It was also proven that BaP could be sufficiently decomposed under irradiation by fluorescent lamp (59 % in comparison to 64 % under same environmental conditions with use of UV light). However, its decomposition rate was approximately 5 times slower than under UV light

Enhancing the Strengths of Adhesion Bonds Between Composite Surface and Coating via UV Treatments

2017 ◽  
Author(s):  
R. Asmatulu ◽  
K. S. Erukala ◽  
M. M. Rahman
Keyword(s):  
Contact Angle ◽  
Uv Radiation ◽  
Uv Light ◽  
Composite Coatings ◽  
Weight Ratio ◽  
High Strength ◽  
Water Contact ◽  
Composite Surface ◽  
Adhesion Properties ◽  
Infrared Spectrometer

Field of composites is rapidly growing in many industries such as aviation, energy and automotive industries. Composites are known to have a high strength to low weight ratio. Significant improvement in the performance of coatings used in the protection of military and civil aircraft has been achieved the last thirty years. Composite coatings are exposed to many environmental conditions, which can significantly affect their properties. In this research, UV light treatment on the surface of composite was introduced to examine its effects on the adhesion properties between the coating and substrate. A cross-cut test was conducted on the composite panels to assess the adhesion of paint to the substrate after the treatments. Coating performance analyses were also carried out using a Fourier transform infrared spectrometer, water contact angle, and optical microscopic images. The first set of panels was treated with UV radiation for 0, 2, 4 and, 8 days, and the surface wettability was also assessed using the contact angle test. Two coats of paints, including a primer and top coat, were used, and the panels were exposed to UV radiation and immersed in water for 500 hrs and 1000 hrs. It was found that untreated panels showed a much higher contact angle of 106°, whereas the contact angle of panels treated with UV radiation was reduced to 47°. The cross-cut tests showed considerable flaking of the coating along the edges and squares of panels that were not treated, and very small flakes along the edges and parts of the grid square on panels that were UV treated, thus confirming the enhancement of coating adhesion between composite and coating surfaces by UV treatments.

Restrained Shrinkage Behavior of Concrete under Different Environmental Conditions

2014 ◽  
Vol 941-944 ◽  
pp. 835-841 ◽  
Author(s):  
Zhi Tao Chen ◽  
Mao Guang Li ◽  
Ying Zi Yang ◽  
Qi Liu
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Test Method ◽  
Mineral Admixtures ◽  
Ring Test ◽  
Test Duration ◽  
Restrained Shrinkage ◽  
Shrinkage Cracking ◽  
Higher Temperature ◽  
Shrinkage Behavior

The ring test method is used to evaluate the behavior of concrete under restrained shrinkage. Four kinds of environmental conditions (20±1°C, RH60±5%; 35±1°C, RH60±5%; 50±1°C, RH15±5%; 65±1°C, RH15±5%) were designed to investigate the effect the environmental condition on the shrinkage behavior of concrete prepared with different kinds of mineral admixtures. The results show that higher temperature and lower relative humidity can increase the risk of shrinkage cracking. The addition of different mineral admixtures increases the shrinkage of concrete at room conditions. In the case of higher temperature and lower relative humidity, the addition of mineral admixtures can delay the shrinkage cracking in the test duration.

Influence of Mixing Environmental Conditions on Flowability of Lactose Blends

2014 ◽  
Vol 633 ◽  
pp. 3-6 ◽  
Author(s):  
Xiang Yun Lu ◽  
Lan Chen ◽  
Rui Lin Heng ◽  
Yun Zhang Cheng ◽  
Umezuruike Linus Opara
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Environmental Temperature ◽  
Dry Powder ◽  
Temperature And Humidity ◽  
Powder Flowability ◽  
Higher Temperature ◽  
Effects Of Temperature

Powder flowability is one of the most important properties affecting the filling and delivering processes of dry powder inhalations. When the powder is exposed to different environmental (temperature, relative humidity (RH)) conditions, the interaction between particulates would influence the flowability of powders. Blends of 83% coarse lactose (D50=126μm) and 17% fine lactose (D50= 7μm) were prepared at three different mixing environments and the effects of temperature and humidity on powder flowability were investigated. Results indicated that mixing under relatively higher temperature and lower RH environmental conditions improved the flowability of lactose blends.

Facile fabrication of ultraviolet-protective silk fabrics via atomic layer deposition of TiO2 with subsequent polyvinylsilsesquioxane modification

2018 ◽  
Vol 89 (17) ◽  
pp. 3529-3538 ◽  
Author(s):  
Huiyu Yang ◽  
Yaling Wang ◽  
Keshuai Liu ◽  
Xin Liu ◽  
Fengxiang Chen ◽  
...  
Keyword(s):  
Contact Angle ◽  
Atomic Layer Deposition ◽  
Water Contact Angle ◽  
Uv Light ◽  
Water Repellency ◽  
Atomic Layer ◽  
Water Contact ◽  
Force Microscopy ◽  
Layer Deposition ◽  
Silk Fabrics

To develop ultraviolet (UV) light-protective silk fabrics (SFs), a conformal nanoscale TiO2 coating was deposited using an atomic layer deposition (ALD) method, and polyvinylsilsesquioxanes (PVSs) were further coated onto the SFs to enhance their hydrophobicity and UV light-resistance. Scanning electron microscopy and atomic force microscopy revealed hierarchical microstructures and nanostructures of the TiO2 coatings, which were primarily responsible for the increase of the water contact angle from approximately 0 to 120° after the ALD process. A high mean square surface roughness of 76.325 nm also accounted for this improved water contact angle. Furthermore, TiO2-coated SFs modified with low surface energy PVSs exhibited enhanced hydrophobic properties. More importantly, both the UV-blocking and yellowing-resistance of the SFs were improved without any significant change to the luster of the SFs. The ease and simplicity of this fabrication method makes it applicable to the preparation of multifunctional textiles with both good water repellency and UV-resistance.

scholarly journals Evaluation of Silkworm Lines against Variations in Temperature and RH for Various Parameters of Commercial Cocoon Production

2011 ◽  
Vol 2011 ◽  
pp. 1-11
Author(s):  
Mubashar Hussain ◽  
Shakil Ahmad Khan ◽  
Muhammad Naeem ◽  
Tahir Aqil ◽  
Rizwan Khursheed ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Poor Performance ◽  
Evaluation Index ◽  
Larval Rearing ◽  
Cocoon Production ◽  
Influence Of Temperature ◽  
Different Temperatures ◽  
Higher Temperature ◽  
Almost All

Eleven inbred silkworm lines (M-101, M-103, M-104, M-107, Pak-1, Pak-3, Pak-2, Pak-4, PFI-1, PFI-2, and S-1) were evaluated for various parameters of cocoon production under different temperature and relative humidity conditions (25±1,30±1, and35±1 °Cin combination with 55, 65, and 75% RH for three hrs during 4th and 5th instar. The experiment was laid out in factorial design with three replications. Significant variations in the performance of silkworm lines were noticed due to influence of temperature and RH treatment on 4th and 5th instar larvae. The silkworm lines performed significantly better when the larvae were reared at25±1 °Cwith 70–80% RH while almost all the silkworm lines showed poor performance at higher temperature exposures for 3 hrs. Exposures to lower humidity (55%) during larval rearing in 4th and 5th instar at different temperatures (25±1,30±1, and35±1 °C) resulted in lowering the cocoon production. The cumulative evaluation index values for different traits showed that Pak-4 (61.42) was the best line followed by M-101 (59.15), Pak-2 (56.37), Pak-3 (52.83) PFI-I (52.62), and M-107(50.03). The study clearly underlines the importance of optimization of environmental conditions during larval rearing in relation to commercial cocoon production. The investigations strongly recommend that temperature and relative humidity in the range of 25-26 °Cand 70–80%, respectively, are mandatory for excellent results of cocoon production and Pak-4, M-101, Pak-2, Pak-3, PFI-I, and M-107 were suitable for commercial rearing.

Long-Term Stable Metal Organic Framework (MOF) Based Mixed Matrix Membranes for Ultrafiltration

2020 ◽  
Author(s):  
Muayad Al-shaeli ◽  
Stefan J. D. Smith ◽  
Shanxue Jiang ◽  
Huanting Wang ◽  
Kaisong Zhang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Mixed Matrix Membranes ◽  
Recovery Ratio ◽  
Mixed Matrix ◽  
Water Contact ◽  
Membrane Performance ◽  
Metal Organic ◽  
Matrix Membranes

<p>In this study, novel <a>mixed matrix polyethersulfone (PES) membranes</a> were synthesized by using two different kinds of metal organic frameworks (MOFs), namely UiO-66 and UiO-66-NH<sub>2</sub>. The composite membranes were characterised by SEM, EDX, FTIR, PXRD, water contact angle, porosity, pore size, etc. Membrane performance was investigated by water permeation flux, flux recovery ratio, fouling resistance and anti-fouling performance. The stability test was also conducted for the prepared mixed matrix membranes. A higher reduction in the water contact angle was observed after adding both MOFs to the PES and sulfonated PES membranes compared to pristine PES membranes. An enhancement in membrane performance was observed by embedding the MOF into PES membrane matrix, which may be attributed to the super-hydrophilic porous structure of UiO-66-NH<sub>2</sub> nanoparticles and hydrophilic structure of UiO-66 nanoparticles that could accelerate the exchange rate between solvent and non-solvent during the phase inversion process. By adding the MOFs into PES matrix, the flux recovery ratio was increased greatly (more than 99% for most mixed matrix membranes). The mixed matrix membranes showed higher resistance to protein adsorption compared to pristine PES membranes. After immersing the membranes in water for 3 months, 6 months and 12 months, both MOFs were stable and retained their structure. This study indicates that UiO-66 and UiO-66-NH<sub>2</sub> are great candidates for designing long-term stable mixed matrix membranes with higher anti-fouling performance.</p>

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