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Bu çalışmada önemli bir yağ asidi olan pentanoik asidin hidroksiapatit kristalizasyonu üzerine olan etkisi incelenmiştir. Bu amaçla kristalizasyon deneyleri saf ortamda ve 100, 500 ve 1000 ppm olmak üzere üç farklı pentanoik asit konsantrasyonunda kesikli bir sistemde yürütülmüştür. Elde edilen hidroksiapatit kristalleri, XRD, SEM, tane boyutu, BET, FTIR, zeta potansiyeli ve TG analiz yöntemleri kullanılarak karakterize edilmiştir. Pentanoik asit varlığında, hidroksiapatit kristallerin ortalama tane boyutunun saf ortama göre arttığı, kristal morfolojisinde önemli değişiklikler meydana geldiği belirlenmiştir. FTIR analiz sonuçları, katkı maddesi olarak kullanılan pentanoik asidin kristal yüzeyine tutunduğunu göstermiş ve bu sonuçlar zeta potansiyeli ölçümleri ile desteklenmiştir. Saf ortamda üretilen hidroksiapatit kristallerinin zeta potansiyeli -20,9±1,1 mV iken kristallerin yüzey yükleri 1000 ppm pentanoik asit konsantrasyonunda +2,1±1,3 mV değerine ulaşmıştır. Ayrıca hidroksiapatit kristallerinin termal bozunma kinetiği Kissinger ve Coats-Redfern yöntemleri kullanılarak incelenmiştir. Saf ortamda elde edilen hidroksiapatit kristallerinin termal bozunması sırasında gerekli olan ortalama aktivasyon enerjisi Kissinger modeli kullanılarak 538,51 kJ/mol olarak belirlenmiştir. Bu değer pentanoik asit ortamında üretilen kristaller için ise 580,99 kJ/mol olarak hesaplanmıştır. Coats Redfern kinetik modeline göre hem saf hem de katkı ortamı için 3D difüzyon modelinin hidroksiapatitin termal bozunma sürecini en iyi karakterize eden mekanizma olduğu belirlenmiştir.
In this study, the effect of pentanoic acid, an important fatty acid, on hydroxyapathic crystallization was studied. For this purpose, crystallization experiments have been carried out in a clean environment and in a cutting system in three different concentrations of pentanoic acid, 100, 500 and 1000 ppm. The acquired hydroxyapathic crystals are characterized by the use of XRD, SEM, one size, BET, FTIR, Zeta potential and TG analysis methods. In the presence of pentanoic acid, the average one size of hydroxyapathic crystals has increased according to the pure environment, significant changes in the crystal morphology have occurred. The results of the FTIR analysis showed that the pentanoic acid used as a additive was kept on the crystal surface and these results were supported by measurements of zeta potential. The zeta potential of hydroxyapathic crystals produced in a pure environment is -20,9±1,1 mV, while the surface loads of the crystals at 1000 ppm pentanoic acid concentration have reached +2,1±1,3 mV. The thermal decomposition kinetics of hydroxyapathic crystals has also been studied using the methods of Kissinger and Coats-Redfern. The average activation energy required during the thermal decomposition of hydroxyapathic crystals obtained in a clean environment was determined to 538,51 kJ/mol using the Kissinger model. This value is calculated for the crystals produced in the pentanoic acid environment as 580,99 kJ/mol. According to the Coats Redfern kinetic model, the 3D diffusion model for both pure and contributing environments has been determined to be the mechanism that best characterizes the thermal disintegration process of hydroxyapathin.
The effect of pentanoic acid, an important fatty acid, on hydroxyapatite crystallization was investigated in this study. The crystallization experiments were performed in pure media and in the presence of three different pentanoic acid concentrations as 100, 500 and 1000 ppm in a batch system. The hydroxyapatite crystals obtained were characterized by XRD, SEM, particle size, BET, FTIR, zeta potential and TG analysis techniques. Compared to pure media, the particle size of the hydroxyapatite obtained in pentanoic acid media increased, significant changes in crystal morphology were determined. The results of FTIR showed that pentanoic acid used as the additive adsorbed onto the surface of the hydroxyapatite crystals and this result was supported by zeta potential measurements. While the zeta potential of hydroxyapatite crystals obtained in pure media was -20.9 ± 1.1 mV, this value was + 2.1 ± 1.3 mV for 1000 ppm pentanoic acid media. In addition, the thermal decomposition kinetics of hydroxyapatite crystal was investigated using Kissinger and Coats-Redfern models. The average activation energy value for the decomposition of crystals was 538.51 kJ / mol. This value was calculated as 580.99 kJ / mol for crystals obtained in pentanoic acid media. According to the Coats Redfern kinetic model, the 3D diffusion model was determined to be the best model to characterize the thermal decomposition behavior of the hydroxyapatite crystals.
Alan : Eğitim Bilimleri; Fen Bilimleri ve Matematik; Mühendislik
Dergi Türü : Ulusal
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