scholarly journals Photo Initiated Chemical Vapour Deposition To Increase Polymer Hydrophobicity

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Ariane Bérard ◽  
Gregory S. Patience ◽  
Gérald Chouinard ◽  
Jason R. Tavares
Keyword(s):  
Contact Angle ◽  
Chemical Vapour Deposition ◽  
High Density Polyethylene ◽  
Vapour Deposition ◽  
Venturia Inaequalis ◽  
Chemical Vapour ◽  
Superhydrophobic Coating ◽  
Water Ingress ◽  
New Challenges ◽  
Lower Contact

Abstract Apple growers face new challenges to produce organic apples and now many cover orchards with high-density polyethylene (HDPE) nets to exclude insects, rather than spraying insecticides. However, rainwater- associated wetness favours the development of apple scabs, Venturia inaequalis, whose lesions accumulate on the leaves and fruit causing unsightly spots. Treating the nets with a superhydrophobic coating should reduce the amount of water that passes through the net. Here we treat HDPE and polyethylene terephthalate using photo-initiated chemical vapour deposition (PICVD). We placed polymer samples in a quartz tube and passed a mixture of H2 and CO through it while a UVC lamp (254 nm) illuminated the surface. After the treatment, the contact angle between water droplets and the surface increased by an average of 20°. The contact angle of samples placed 70 cm from the entrance of the tube was higher than those at 45 cm and 20 cm. The PICVD-treated HDPE achieved a contact angle of 124°. Nets spray coated with a solvent-based commercial product achieved 180° but water ingress was, surprisingly, higher than that for nets with a lower contact angle.

Hydrophilic TiO2 nanowires prepared on Ti5Si3 layer by chemical vapour deposition

2017 ◽  
Vol 41 (5) ◽  
pp. 304-308 ◽  
Author(s):  
Jun Du ◽  
Wenqian Qi ◽  
Jingjing Zuo ◽  
Xiuyun Li ◽  
Xin Gu ◽  
...  
Keyword(s):  
Contact Angle ◽  
Chemical Vapour Deposition ◽  
Ultraviolet Irradiation ◽  
Growth Process ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
High Density ◽  
Tio2 Nanowires ◽  
Single Crystalline ◽  
Hydrophilic Property

Here we report a self-induced catalyst-free preparation of TiO2 nanowires by APCVD. High-density single-crystalline hydrophilic TiO2 nanowires have been successfully prepared on a Ti5Si3 layer by chemical vapour deposition at 720 °C using 10 SCCM O2 for 120 min, using SiH4, TiCl4, and O2 as precursors. The nanowires are approximately 2–5 μm long, the diameter is about 20–40 nm. The TiO2 nanowires grow along the [001] direction of the tetragonal rutile TiO2 crystal from the bottom, with the tip being pushed upwards. The growth process can be defined as a self-induced growth. The 432 and 463 nm band of TiO2 nanowires assigned to self-trapped excitons and OVs, which is beneficial for the hydrophilic property of the nanowires. The contact angle of TiO2 nanowires after ultraviolet irradiation is low (5.1°), exhibiting excellent hydrophilic property.

Low-pressure chemical vapour deposition of mullite coatings in a cold-wall reactor

1999 ◽  
Vol 09 (PR8) ◽  
pp. Pr8-395-Pr8-402 ◽  
Author(s):  
B. Armas ◽  
M. de Icaza Herrera ◽  
C. Combescure ◽  
F. Sibieude ◽  
D. Thenegal
Keyword(s):  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Low Pressure ◽  
Cold Wall ◽  
Pressure Chemical ◽  
Mullite Coatings

Thermodynamical and experimental conditions of hafnium carbide chemical vapour deposition

1999 ◽  
Vol 09 (PR8) ◽  
pp. Pr8-373-Pr8-380 ◽  
Author(s):  
P. Sourdiaucourt ◽  
A. Derré ◽  
P. Delhaès ◽  
P. David
Keyword(s):  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Hafnium Carbide ◽  
Experimental Conditions

Reduction of carbon impurities in aluminium nitride from time-resolved chemical vapour deposition using trimethylaluminum

2020 ◽  
Author(s):  
Polla Rouf ◽  
Pitsiri Sukkaew ◽  
Lars Ojamäe ◽  
Henrik Pedersen
Keyword(s):  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Aluminium Nitride ◽  
Methyl Groups ◽  
Time Resolved ◽  
Thermally Induced ◽  
Light Emitting ◽  
Carbon Impurities ◽  
Wide Range

<p>Aluminium nitride (AlN) is a semiconductor with a wide range of applications from light emitting diodes to high frequency transistors. Electronic grade AlN is routinely deposited at 1000 °C by chemical vapour deposition (CVD) using trimethylaluminium (TMA) and NH<sub>3</sub> while low temperature CVD routes to high quality AlN are scarce and suffer from high levels of carbon impurities in the film. We report on an ALD-like CVD approach with time-resolved precursor supply where thermally induced desorption of methyl groups from the AlN surface is enhanced by the addition of an extra pulse, H<sub>2</sub>, N<sub>2</sub> or Ar between the TMA and NH<sub>3</sub> pulses. The enhanced desorption allowed deposition of AlN films with carbon content of 1 at. % at 480 °C. Kinetic- and quantum chemical modelling suggest that the extra pulse between TMA and NH<sub>3</sub> prevents re-adsorption of desorbing methyl groups terminating the AlN surface after the TMA pulse. </p>

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