Thermal Decomposition of Ionic Solids (eBook)

Cover 1
Summary Contents 11
Detailed Contents 12
Part A: Theory and Background 28
Chapter 1. Introduction 30
1.1. Decomposition of solids 30
1.2. The solid state 31
1.3. Classification of solids 33
1.4. Crystal imperfections 37
1.5. Mobility of defects in solids 45
1.6. A simplified model of the decomposition process 54
References 56
Chapter 2. Stoichiometry and Exrent of Decomposition 58
2.1. Introduction 58
2.2. The fractional decomposition (a) 59
2.3. The reactant 60
2.4. Changes preceding or accompanying decomposition 61
2.5. Thermodynamic feasibility of decomposition 79
2.6. Thermodynamic prediction of decomposition products 82
2.7. Reversible solid state reactions 89
2.8. Experimental determination of the stoichiometry and extent of reaction 89
2.9. Temperature measurement, control and calibration 93
2.10. Thermochemical measurements 95
2.11. Comparison of thermochemical and kinetic parameters 96
2.12. Conclusions 98
References 98
Chapter 3. Kinetic Models for Solid-State Reactions 104
3.1. Introduction 104
3.2. Nucleation and growth of nuclei 105
3.3. Kinetics of nucleation 106
3.4. Kinetics of growth 112
3.5. Combination of kinetics of nucleation and growth 115
3.6. Geometrical models 120
3.7. Models based on autocatalysis 123
3.8. Diffusion models 125
3.9. Models based on 'order of reaction' 129
3.10. Allowance for particle-size effects 129
3.11. The most important rate equations used in solid-state reactions 131
3.12. Isothermal yield-time curves 135
3.13. Conclusions 139
References 140
Chapter 4. The Influence of Temperature on Reaction Rate 146
4.1. Introduction 146
4.2. Variables other than temperature 147
4.3. Alternatives to the Arrhenius equation 147
4.4. Determination of the magnitudes of the Arrhenius parameters, Ea and A 148
4.5. The Polanyi-Wigner equation 152
4.6. Transition-state description 153
4.7. The significance of the activation energy 154
4.8. Structure of the active reaction zone and interface chemistry 155
4.9. The compensation effect 158
4.10. Reaction mechanisms 162
References 164
Chapter 5. Analysis and Interpretation of Experimental kinetic Measurements 168
5.1. Introduction 168
5.2. The experimental results 168
5.3. Identification of the rate equation that gives the best representation of the experimental data 170
5.4. Methods of kinetic analysis of isothermal data 170
5.5. Non-isothermal kinetic analysis 176
5.6. Conclusions 194
References 196
Chapter 6. Characterization of Reactants, Decomposition Intermediates and Products, and The Formulation of Mechanisms 202
6.1. Introduction 202
6.2. Characterization of solid reactants, intermediates and products 203
6.3. Microscopic examination of the reactant sample before, during and after decomposition 215
6.4 Surface Area and Particle Size 219
6.5. Other physical properties 219
6.6. Reactant doping 221
6.7. Pre-irradiation studies 223
6.8. Interface chemistry 223
6.9. Mechanochemistry 231
6.10. Reactant melting 232
6.11. Analysis of gaseous products 234
6.12. Conclusions 235
References 238
Part B: Thermal Decomposition of Selected Ionic Solids 244
Chapter 7. Thermal Dehydration of Hydrated salts 246
7.1. Introduction 246
7.2. Structural considerations 247
7.3. Experimental methods 248
7.4. Stoichiometry of reaction 250
7.5. Kinetics of dehydration 250
7.6. Arrhenius parameters calculated for interface reactions 251
7.7. The Smith-Topley effect 253
7.8. Hydrates of metal sulfates 256
7.9. Alums 265
7.10. Hydrates of other inorganic salts 270
7.11. Hydrates of metal oxalates 275
7.12. Hydrates of metal formates 278
7.13. Hydrates of metal salts of other organic acids 279
7.14. Complex materials 282
7.15. Perhydrates 283
7.16. Conclusions 284
References 290
Chapter 8. Thermal Dehydration of Hydroxides 298
8.1. Introduction 298
8.2. Group IIA metal hydroxides 299
8.3. Aluminium hydroxides 302
8.4. Zinc and cadmium hydroxides 305
8.5. Tin(IV) hydroxides 306
8.6. Transition metal hydroxides 306
8.7. General considerations 310
8.8. Catalyst production 311
8.9. Dehydration of layer silicates 312
8.10. Conclusions 315
References 317
Chapter 9. The Thermal Dissociation of Oxides 320
9.1. Introduction 320
9.2. Chemistry of oxides 320
9.3. Dissociation of oxides 325
9.4. Refractory oxides: extended imperfections - crystallographic shear and block structures 335
9.5. High temperature volatilization of oxides 336
9.6. Conclusions 337
References 338
Chapter 10. Decomposition of other Binary Compounds 342
10.1. Introduction 342
10.2. Metal hydrides 342
10.3. Metal carbides 346
10.4. Metal nitrides 349
10.5. Metal sulfides 350
10.6. Conclusions 353
References 354
Chapter 11. Decomposition of Azides 358
11.1. Introduction 358
11.2. Group IIA (alkaline earth) metal azides 360
11.3. Group IA (alkali) metal azides 362
11.4. Other azides 364
11.5. Metal cyanamides and fulminates 366
11.6. Conclusions 368
References 370
Chapter 12. Decomposition of Carbonates 374
12.1. Introduction 374
12.2. Calcium carbonate 374
12.3. Other Group IIA metal carbonates 378
12.4. Group IA metal carbonates and bicarbonates 380
12.5. Silver carbonate 382
12.6. Lead carbonate 383
12.7. Zinc carbonate 383
12.8. Cadmium carbonate 384
12.9. Other carbonates 384
12.10. Kinetic summary 386
12.11. Conclusions 386
References 390
Chapter 13. Decomposition of metal Perhalates, Halates and Halites 394
13.1. Introduction 394
13.2. Metal perchlorates 394
13.3. Metal perbromates and periodates 398
13.4. Metal chlorates 399
13.5. Metal bromates and iodates 400
13.6. Metal halites 402
13.7. Radiolysis of oxyhalides 403
13.8. Halides and hydroxyhalides 403
13.9. Conclusions 405
References 406
Chapter 14. Decomposition of Metalsalts of Various Oxyaxids 410
14.1. Introduction 410
14.2. Permanganates 410
14.3. Chromates 418
14.4. Nitrates and nitrites 419
14.5. Phosphates 424
14.6. Sulfates 427
14.7. Sulfites 431
14.8. Thiosulfates 432
14.9. Conclusions 432
References 438
Chapter 15. Decomposition of Ammonium Salts 444
15.1. Introduction 444
15.2. Ammonium perchlorate 444
15.3. Nitronium and nitrosonium perchlorates 451
15.4. Ammonium halates 451
15.5. Ammonium nitrate 453
15.6. Ammonium phosphates 454
15.7. Ammonium sulfates 455
15.8. Ammonium vanadates 456
15.9. Ammonium chromates 457
15.10.Ammonium permanganate 459
15.11.Other ammonium salts 460
15.12.Conclusions 463
References 464
Chapter 16. The Thermal Decompositions of Metal salts of Organic acids 470
16.1. Introduction 470
16.2. Metal formates 470
16.3. Metal acetates 477
16.4. Metal oxalates 481
16.5. Metal mellitates 496
16.6. Metal squarates 496
16.7. Metal malonates, fumarates and maleates 498
16.8. Other metal carboxylates 504
16.9. General conclusions 507
References 515
Chapter 17. Decompositions of Coordination Compounds 522
17.1. Introduction 522
17.2. Mononuclear coordination compotmds with monodentate ligands 524
17.3. Mononuclear coordination compounds with polydentate ligands 541
17.4. Bmuclear coordination compounds with polydentate ligands 546
17.5. Factors influencing the thermal stability of coordination compotmds 546
17.6. Conclusions 549
References 551
Chapter 18. The Present Position and Prospects for Future Progress in Studies of Thermal Decompositions of Solids 556
18.1. Overview 556
18.2. The controlling step in solid state decompositions 557
18.3. The structural complexity of the interface 562
18.4. Reactant surface chemistry and nucleation 563
18.5. Experimental evidence in formulating reaction mechanisms 564
18.6. Kinetic parameters 568
18.7. Reaction mechanisms 571
18.8. Some patterns of kinetic behaviour 574
18.9. The literature concerned with crystolysis reactions 577
18.10. Relationships with neighbouring subject areas 580
18.11. Some general comments 581
18.12. An agenda for the future 587
References 590
Glossary 596
Index 602