Pattern fabrication of element-doped DLC films and investigation of their barnacle adhesion suppression effect
1DBarnacle
@Economic damage and environmental problems caused by barnacles adhering to ship hulls, power plant cooling system pipes, and other structures have become an issue.
Organotin-based compound paints such as tributyltin (TBT) used to be used in the past, but their use has been banned due to the toxicity of organotin compounds that have a negative impact on the environment.
Therefore, various anti-adhesion measures are currently being researched as alternatives to TBT paints.
@It has been reported that barnacles engage in adhesive behavior by secreting multiple proteins, and that changes in wettability affect protein adsorption. However, the optimal wettability varies with the type of protein.
Fig.1 Barnacles attached to a ship[1]
@ @DLC films are amorphous carbon with an irregular mixture of carbon with a diamond structure (sp3 bonds) and graphite structure (sp2 bonds). The physical properties of DLC vary depending on the hydrogen content and sp3/sp2 ratio. Therefore, DLC is used in a wide range of applications, including automotive parts, cutting tools, and PET bottles.
DLC films are also being considered for application in marine environments, and there are studies using DLC films to prevent barnacle adhesion.[2]
Fig.2 PET bottles with DLC coating[3]
EDLC Features
EHigh hardness
Ecorrosion resistance
Eabrasion resistance
ELow coefficient of friction
EGas barrier property@@etc.
2DDLC Coating Methods
@DLC film coating methods include plasma CVD, ion beam, arc, and pulsed laser methods. The principle of the plasma CVD method is explained below.
EPlasma CVD method
@This principle is a method in which hydrocarbon gas is introduced, plasmaized by high-frequency discharge or other means, and carbon or hydrogen is deposited on a substrate placed on top of electrodes. The chamber is kept in a medium vacuum and methane CH4 is used as the main gas. The deposition temperature can be as low as 200C.
Fig.3 Schematic diagram of RF-CVD system
3DElement addition and patterned thin films
EElement addition
@This is a method of controlling the physical properties of DLC films by adding elements to DLC.
By adding elements, it is possible to improve various properties.
One of them is the change in wettability. By adding elements, it is possible to give hydrophilic and hydrophobic properties to the DLC film.
EPatterned thin films
@Patterned thin film is a thin film with an uneven surface on the substrate surface using a pattern mask or other means.
@The attachment behavior of barnacles is believed to be related to the unevenness of the surface shape.[4]
@ 4DPurpose of This Research
@The purpose of this study is to pattern DLC films with elemental additions and to evaluate barnacle adhesion due to differences in wettability.
Slides
[1]YUIME japan https://yuime.jp/post/fishing-boat-barnacles-countermeasures
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[3]OHP~Jz[fBOXO[v, PET{g, https://www.m-chemical.co.jp/products/departments/mcc/food-packaging/product/1200448_7250.html
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