This work contains comparison of morphology and chemical structure of hydroxyapatite (HAP) films obtained by sol-gel and RF PECVD methods. HAP films obtained by sol-gel method were deposited by dip-coating on silicon and stainless steel substrates and next annealed at the temperature of 500°C. In the PECVD method, the possibility of sputtering of metallic calcium was used, while the phosphorus compound was inserted into the reactor`s chamber in the form of vapour. The deposition process was performed in low temperature plasma. It was found that both RF PECVD and sol-gel methods could be used to obtain HAP layers. Coatings produced In both methods revealed good quality. The chemical structure of films was investigated by the use of FTIR spectrometer. The analysis of FTIR spectra indicated that the main phase of coatings was carbonate hydroxyapatite but coatings deposited by sol-gel method were crystalline while coatings manufactured by RF PECVD were amorphous.
PL
Praca zawiera porównanie morfologii i budowy chemicznej warstw hydroksyapatytu (HAP) otrzymywanych za pomocą metod zol-żel oraz RF PECVD. Powłoki HAP otrzymywane sposobem zol-żel nakładane były metodą wynurzeniową na podłoża krzemowe i ze stali kwasoodpornej, a następnie wygrzewane w temperaturze 500°C. W metodzie PECVD metaliczny wapń rozpylany był w komorze reaktora, natomiast fosfor wprowadzano w postaci pary. Proces nakładania przeprowadzano w wyładowaniu plazmy niskotemperaturowej. Stwierdzono, że za pomocą obu metod otrzymano dobrej jakości powłoki HAP. Strukturę chemiczną warstw badano za pomocą spektrometru podczewieni (FTIR). Analiza widm FTIR wykazała, że główną fazą otrzymywanych powłok był hydroksyapatyt węglanowy, jednak powłoki otrzymywane metodą zol-żel były krystaliczne, zaś wytwarzane metodą RF PECVD amorficzne.
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Purpose: of this paper is show how parylene coatings can protect biological specimens. Design/methodology/approach: Parylene technology is a process, in which a thin polymer film of a very uniform thickness is deposited onto the entire surface of any object placed in the reactor. The polymer, either poly-para-xylylene or one of its ring substituted derivatives, is characterized by excellent mechanical and dielectric [1] as well as barrier [2] properties, at the same time being transparent in the entire visible range of radiation. The process takes place at room temperature, which permits to use virtually any material as substrate. Findings: The following work reports results of parylene application to the conservation of such natural objects, as Pieris brassicae butterflies, Pygocentrus piranya pirania fish and Quercus L. oak leaves. The number of specimens was always divided in two, of which one part was coated with 4 micrometers of Parylene C while the other remained uncoated as a reference sample. All the specimen were then placed on the surface of garden soil and kept there at constant temperature of 37°C and constant humidity of 75%, where their disintegration was followed by means of optical microscopy. After several months of staying under these conditions all the coated specimens were intact remaining their full integrity and colors. In contrast to that, the uncoated fish began to decompose after nine days, the uncoated butterflies after twenty one days and uncoated leaves after three months. Practical implications: A very tight deposition, at room temperature of such a coating onto practically any object obviously focuses an attention of conservators of both natural and cultural human heritage [3-6]. Probably the most important advantage of this technology is its extraordinary penetration ability. When coating a fabric, for instance, this feature allows one to deposit parylene film onto single fibers, leaving open space in-between and simultaneously reinforcing the knots. This is the reason why parylene technology is most often used in the conservation of paper [5] and silk [6]. Originality/value: The originality of present investigation is in application of parylene coatings. The method should be interest for the conservation applications.
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