Thermal kinetics and thermodynamics of the dehydration reaction of Mg3(PO4)2·22H2O

Year 2019, Volume: 2 Issue: 2, 47 - 51, 06.12.2019

Fatma Tuğçe Şenberber , Emek Möröydor Derun

Abstract

Mg₃(PO₄)₂·22H₂O
lost its crystal water in the temperature range of 40 - 200°C and the calcined
sample was identified as Mg₃(PO₄)₂, was a
notable for its further treatments in optical and electrical applications.
Dehydration process was studied using non-isothermal thermogravimetry (TG)
applying model-fitting method. Different mechanism models (chemical reaction
order, diffusion and phase interfacial reaction) were applied. The activation
energies calculated for the dehydration reaction; and average of activation
energy was found as 160 kJ/mol.  The
better kinetic model of the dehydration reaction for Mg₃(PO₄)₂·22H₂O
was selected as F3 (chemical reaction - third order). The thermodynamic
functions (ΔH, ΔG and ΔS) of the dehydration reaction were calculated by the
activated complex theory and found that the process was endothermic,
non-spontaneous and fast.

Keywords

Magnesium phosphate, decomposition kinetic, thermal behaviour, thermodynamic

References

• Aramendia MA, Borau V, Jimenez C, Marinas JM, Romero FJ 1999. Synthesis and characterization of magnesium phosphates and their catalytic properties in the conversion of 2-hexanol. Journal of Colloid and Interface Science, 217: 288–298.
• Assaaoudi H, Fang Z, Butler IS, Ryan DH, Kozinski JA 2007. Characterization of a new magnesium hydrogen orthophosphate salt, Mg3.5H2(PO4)3, synthesized in supercritical water. Solid State Sciences 9: 385 – 393.
• Boonchom B 2008. Kinetics and Thermodynamic Properties of the Thermal Decomposition of Manganese Dihydrogenphosphate Dihydrate. Journal of Chemical Engineering Data, 53: 1533–1538.
• Boonchom B 2009. Kinetic and thermodynamic studies of MgHPO4·3H2O by non-isothermal decomposition data. Journal of Thermal Analysis and Calorimetry, 98: 863–871.
• Boonchom B, Danvirutai C 2008. A simple synthesis and thermal decomposition kinetics of MnHPO4·H2O rod-like microparticles obtained by spontaneous precipitation route. Journal Of Optoelectronics And Advanced Materials, 10(3): 492 – 499.
• Boonchom B, Puttawong S 2010. Thermodynamics and kinetics of the dehydration reaction of FePO42H2O, Physica B, 405: 2350–2355.
• Debnath S, Saxena SK, Nagabhatla V 2016. Facile synthesis of crystalline nanoporous Mg3(PO4)2 and its application to aerobic oxidation of alcohols. Catalysis Communications 84: 129–133.
• Gopinath P, Ramalingam V, Breslow R 2015. Magnesium pyrophosphates in enzyme mimics of nucleotide synthases and kinases and in their prebiotic chemistry. Proceedings of the National Academy of Sciences of the United Sciences, 112(39): 12011–12014.
• Kanazawa T, Umegaki T, Shimizu M 1979. The synthesis of Mg3(PO4)2·8H2O and its polymorphism. Bulletin of the Chemical Society of Japan, 52(12): 3713–3717.
• Kongshaug KO, Fjellvag H, Lillerud 2001. The synthesis and crystal structure of a hydrated magnesium phosphate Mg3(PO4)2·4H2O. Solid State Sciences, 3: 353–360.
• Lopez FA, Tayibi H, Diaz IG, Alguacil FJ 2015. Thermal dehydration kinetics of phosphogypsum. Materiales de Construction, 65(319): 1-14.
• Lu X, Chen B 2016. Experimental study of magnesium phosphate cements modified by metakaolin. Construction and Building Materials, 123: 719–726.
• Mousa S 2010. Study on synthesis of magnesium phosphate materials. Phosphorus Research Bulletin, 24: 16 – 21.
• Naqvi SR, Tariq R, Hameed Z, Ali I, Naqvi M, Chen WH, Ceylan S, Rashid H, Ahmad J, Taqvi SA, Shahbaz M 2018. Pyrolysis of high ash sewage sludge: kinetics and thermodynamic analysis using Coats-Redfern method, Renewable Energy, (In Press) doi: 10.1016/j.renene.2018.07.094
• Pokorny P, Tej P, Szelag P 2016. Discussion about magnesium phosphating. Metalurgija, 55(3): 507–510.Qiao F, Chau CK, Li Z 2010. Property evaluation of magnesium phosphate cement mortar as patch repair material. Construction and Building Materials, 24: 695–700.
• Rouzic M, Chaussadent T, Platret G, Stefan L 2017. Mechanisms of k-struvite formation in magnesium phosphate cements. Cement and Concrete Research, 91: 117–122.
• Sadiq M, Abdennouri M, Barka N, Baalala M, Lamonier C, Bensitel M 2015. Influence of the Crystal Phase of Magnesium Phosphates Catalysts on the Skeletal Isomerization of 3,3-dimethylbut-1-ene. Canadian Chemical Transactions, 3(2): 225–233.
• Sadiq M, Bensitel M, Lamonier C, Leglise J 2008. Influence of the nature of precipitating basic agent on the synthesis of catalytic magnesium phosphate materials. Solid State Sciences, 10: 434–437.
• Sronsri C, Boonchom B 2018. Determination of thermokinetic parameters and thermodynamic functions from thermoforming of LiMnPO4. Journal of Thermal Analysis and Calorimetry, 134(3): 1575 – 1587.
• Wu F, Wei J, Guo H, Chen F, Hong H, Liu C 2008. Self-setting bioactive calcium–magnesium phosphate cement with high strength and degradability for bone regeneration. Acta Biomaterialia, 4: 1873–1884.
• Yang Q, Zhu B, Wu X 2000. Characteristics and durability test of magnesium phosphate cement-based material for rapid repair of concrete. Materials and Structures, 33: 229–234.
• Yu C, Wu Q, Yang J 2017. Effect of seawater for mixing on properties of potassium magnesium phosphate cement paste. Construction and Building Materials, 155: 217–227.
• Yu X, Jiang J 2018. Mineralization and cementing properties of bio-carbonate cement, bio-phosphate cement, and bio-carbonate/phosphate cement: a review. Environmental Science and Pollution Research, 25: 21483–21497.
• Yu XN, Qian CX, Sun LZ 2016. Chemosynthesis of nano-magnesium phosphates and its characterization. Digest Journal of Nanomaterials and Biostructures, 11(4): 1099–1103.
• Zhang S, Li L, Lv X 2016. Synthesis and characterization of a novel Mg3(PO4)2 ceramic with low dielectric constant. Journal of Materials Science: Materials in Electronics, DOI: 10.1007/s10854-016-5703-y
• Zhang Z, Tang W 2015. Tunable Blue–Red Emission and Energy-Transfer Properties of Mg3(PO4)2:Eu2+,Mn2+ Phosphors. Eyropen Journal of Inorganic Chemistry, 2015: 3940–3948.
• Zhou H. Luchini TJF, Bhaduri SB 2012. Microwave assisted synthesis of amorphous magnesium phosphate nanospheres. Journal of Materials Science: Materials in Medicine, 23:2831–2837.