Dissertation > Excellent graduate degree dissertation topics show

Colorimetric Determination of CdS Nanocrystals Concentration

Author: JiYiJing
Tutor: PengXiaoGang；WangGuoPing；WangJie
School: Zhejiang University
Course: Chemistry
Keywords: CdS nanocrystals colorimetry extinction coefficient extraction
CLC: TB383.1
Type: Master's thesis
Year: 2012
Downloads: 39
Quote: 0
Read: Download Dissertation

Abstract


Quantum confinement of semiconductor nanocrystals plays a key role on determination of optical properties of the nanocrystals. For this reason, such semiconductor nanocrystals are known as quantum dots. The unique properties of quantum dots make them useful for fundamental research and technical applications, such as LEDs, biomedical labeling, laser, solar cell, etc. However, some aspects in nanocrystal research need to be clarified, such as purification, extinction coefficient, and concentration of the particles. In this thesis, we studied these problems for CdS nanocrystals.1. Purified using existing purification procedures, CdS nanocrystal were proven still containing unreacted cadmium carboxylate salts. In our research, butylamine was employed to obtain high extraction efficiency by formation of complex with cadmium carboxylate. Results illustrated that such complex can be dissolved in methanol and the nanocrystals remain in heaxnes phase. According to IR spectra, there is barely any cadmium carboxylate left after four methanol/hexane extraction with butylamine addition.2. The absorption peak of cadion with Triton X-100 is at 569nm and the absorption peak of complex that cadion and cadmium formed is at 478nm. The difference between the absorbance of 478nm and 569nm is linear with the concentration of the complex in the range of 0～8μg/mL. In this concentration range, we could calculate the concentration of cadmium ions in acid-digested nanocrystal solution. By considering geometry and crystal sturcture, one can further calcuate the extinction coefficient of the particles. The advantage of colorimetry is simple and readily acessible.3. The colorimetric method can further be used for determination of CdS unit yield without knowing its size and shape. This assisted the determination of critical temperature in CdS nanocrystals synthesis.

Related Dissertations

  1. Research on Automatic Detection Algorithm for Substructure Distress of Highway Pavement Based on SVM,U418.6
  2. ISAR Imaging Simulation of Space Targets and Target Recognition Based on ISAR Images,TN957.52
  3. Research on Feature Extraction and Classification of Tongue Shape and Tooth-Marked Tongue in TCM Tongue Diagnosis,TP391.41
  4. The Application of Eggshell Membrane for Solid-phase Extraction and the Determination of Trace Metal Elements in Environment Water,X832
  5. Study on Separation、 Preconcentration and Analysis of Trace Elements with Carbon Nanometer Materials,TB383.1
  6. Radiation Transfer Characteristics and Radiation Use Efficiency of Rice,S511
  7. Physical Modification of the Soybean Protein Concentrate by Alcohol Extraction,TS201.21
  8. Optimization of Extraction of Gastrodin from Rhizoma Gastrodia by Response Surface Methodology,R284.1
  9. Initial Studies on the Antibacterical Activity in Vitro and the Safety Evaluation of Propolis Extraction,R285
  10. Research of Diagnosing Cucumber Diseases Based on Hyperspectral Imaging,S436.421
  11. Dark purple Fritillaria medicinal active ingredient extraction technology and the chemical composition of,TQ461
  12. Infrared spectroscopy surfactant aqueous two- phase system of,O647.2
  13. Based on high-resolution remote sensing data mining houses information extraction,TP751
  14. Study on Design and Improvement of Mycophenolic Acid Extraction Process,TQ921
  15. Research on Face Recognition Methods Based on Flexible Neural Tree,TP391.41
  16. Research & Implementation of AdaBoost-Based Vehicle Recognition System,TP391.41
  17. Detection、 Tracking and Localization of Multiple Moving Objects Based on Omnidirectional Vision,TP391.41
  18. Study on Data Extraction and Semantic Annotation for Specific Field Deep Web,TP311.13
  19. The Discrimination of Rice Weeds Based on DSP,TP391.41
  20. Research of Fault Diagnosis Method of Analog Circuit Based on Improved Support Vector Machines,TN710
  21. The Study of Extraction, Isolation, Fingerprints of Flavonoids from Citrus Maxima (BURM.) Merr. CV. Wentan,R284

CLC: > Industrial Technology > General industrial technology > Materials science and engineering > Special structural materials
© 2012 www.DissertationTopic.Net  Mobile