الفهرس | Only 14 pages are availabe for public view |
Abstract The mechanisms of crystal growth and dissolution of sparingly soluble salts are considerable interest due to widespread and universal applicability. These mechanisms are one of the oldest and the most frequently used operations in science of chemistry. In many cases, the rates of crystal growth and dissolution are completely accounted by the diffusion mechanism and surface controlled mechanism. Calcium sulfate dihydrate scale formation is an important problem in a number of industrially interesting applications such as production of the oil and gas, hydrometallurgical processes and water cooling systems. Calcium oxalate monohydrate is one of the most important compounds that cause human kidney stones. Due to the problems associated with calcium sulfate dihydrate and Calcium oxalate monohydrate, we undertook the study their rate and mechanisms of dissolution and crystal growth in absence and presence of some additives. The present work includes three chapters as the following: The first chapter is an introduction to some aspects of the crystal growth, dissolution, a scale formation problem, kidney stone disease and effect of additives. It also includes a literature survey on crystal growth/ dissolution of calcium sulfate. It also includes literature survey on crystal growth / dissolution of calcium oxalate. The second chapter includes the experimental part which describes materials, instruments and procedures that have been used throughout the course of investigation. The third chapter comprises the results and discussion. It contain the dissolution of calcium sulfate dihydrate which follow the diffusion mechanism and the rate of its dissolution was inhibited by adding Mg2+, Sr2+ and Ba2+ which was the best inhibitor but it was promoted in presence of Li+. Cystone drug has effect on calcium oxalate monohydrate seed, but Ivypront syrup did not effect on it. Cystone was able to damage and expulsion the kidney stone and it was used as promotor for dissolution of calcium oxalate monohydrate seed. Silver nanoparticles (Ag nanoparticles) were prepared by sodium citrate reduction. The rate of dissolution of calcium oxalate monohydrate seed was inhibited using Ag nanoparticles that were considered as the best inhibitor due to the smallest nanometer size. Finally, using Quartz Crystal Microbalance Apparatus in crystal growth of calcium oxalate monohydrate seed without and with Trizma, the rate of crystal growth was promoted in presence of this additive. |