Essay on Fingerprint Corrosion on Metals

Redox reaction between fingerprint sweat residue and the surface of metals have been expressed as a major factor that causes corrosion on metal alloys. Corrosion of metals such as copper and gold, support the proposition that the extents of metal corrosion are enhanced and promoted by the presence of chlorides ions in fingerprint in ermine sweat (Stefaniak, 2014). When latent fingerprint get deposited on the surface of the metal, it triggers a chemical reaction upon the contact of sweat residue and the metal surface (Midander, 2007). Corrosion on metal can be investigated by heating the metallic material up to temperature 600 degree after deposition of the fingerprints (Bond &, 2008).

Various factors affect corrosion of metal through fingerprint sweat.

The number and the activity of the sweat gland in fingerprints in relative to the contact with the metal surface is a primary factor that causes corrosion on metal (Cook at al, 2015). In the event the amount excretion of sweat is vigorous and the number sweaty fingerprint is in contact with the metal surface is more, the corrosion of metal tends to be significant (Lei, 2016). The secretion rates of the sweat along the fingerprint also by large extent influence the corrosion of metal (Chattoraj, 2007). If the sweat is secreted is at a higher rate, then the area of contact with the metal is likely too large which increases the surface of corrosion on the metal surface (Land, 1972).

The hygroscopicity of the dried residue of the sweat also affects the rate of corrosion on the metal. When the hygroscopic ability of sweat is large such that it can absorb sufficient moisture from the atmosphere, more reaction of metal with fingerprint surface is witnessed, and therefore corrosion tend to be large (Genius, 2012). The temperature of the sweat residue is another crucial factor that affects the corrosion of metal upon contact with fingerprints sweat. When the temperature is substantially low, the concentration of oxygen is often adequate which a key ingredient for metal corrosion (Zheng, 2017). However, when determining sweating rates, a close correspondence is realized using clinical estimation of hyperhidrosis. Corrosion increase with increase in sweats rates, after arise of sodium chloride concentration it reaches its maximum reaction on the skin surface and this contributed by evaporation of water.

According to Hakansson (2016) corrosion resistance of the metal surface also determines the rate and the magnitude of reaction with fingerprints sweat. Some metal alloys have high resistance to corrosion, and regardless of the amount of sweat secreted on its surface, the rate of reaction and consequent corrosion is minimal (Goddard, 2010). The relative humidity and temperature in the environment of contact of the metal surface and fingerprint sweat also by large extent determine the rate of rate of latent reaction (Almog, 2014). Humid environment accelerates corrosion rate of metal as compared to the dry atmosphere. High humidity avails sufficient moisture which is a crucial constituent that influence the reaction of metal and sweat and the ultimate corrosion (Bond & Heidel, 2009).

The oxygen content of fingerprint sweat residue influences the corrosion many metal surface (Bond, 2008). Moisture insulation and crevices cause differential aeration in regards to corrosion of metal. Under this conditions, oxygen-starved in this areas combine with sweat solution which incorporates chloride ions to cause corrosion on the metal surface (Sykes, 2013). Essentially, differential aeration takes place when a difference of oxygen concentration arises. The Parts of the metal that is exposed to a high oxygen concentration is known as the cathode which experiences more corrosion while anode which is poorly oxygenated receives less corrosion (Calderon, 2016). Different people have a distinct rate on how the sweat they secrete corrode metals. Some individuals have sweat which has a high concentration of chloride ions which actively participate in corroding metal. According to Fredj (2013) the more the concentration of ions in sweat the large the corrosion of metal is experienced.

Waterline corrosion is different aeration corrosion; this mainly occurs in, ships, water contains that are made up of steel among others (Stratford & Adams, 1977). These metals are established under water. Waterline corrosion occurs as a result of formation of different oxygen concentration cell (Schafer & Gabriel & Foster, 1960). The part that is below water line is exposed and it end up dissolving oxygen while that parts above the water is reacting with higher oxygen concentration. Thus, the part which is under water acts as anode and undergoes corrosion. A distinct brown ring is formed below water line as a result of deposit of rust (Kobrin, 1976).

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