title: Kinetic study on bonding reaction of gelatin with CdS nanopaticles by UV-visible spectroscopy.
abstract: The chemical kinetics on gelatin-CdS direct conjugates has been systematically investigated as a function of different temperature and reactant concentration (i.e. Cd(2+), S(2-) and gelatin) by UV-visible spectroscopy, for the first time. The nonlinear fitting and the differential method were used to calculate the initial rate based on the absorbance-time data. A double logarithmic linear equation for calculating the rate constant (k) and the reaction order (n) was introduced. The reaction kinetic parameters (n, k, Ea, and Z) and activation thermodynamic parameters (ΔG(≠), ΔH(≠), and ΔS(≠)) were obtained from variable temperature kinetic studies. The overall rate equation allowing evaluation of conditions that provide required reaction rate could be expressed as: r = 1.11 × 10(8) exp(-4971/T)[Cd(2+)][gelatin](0.6)[S(2-)](0.6) (M/S) The calculated values of the reaction rate are well coincide with the experimental results. A suitable kinetic model is also proposed. This work will provide guidance for the rational design of gelatin-directed syntheses of metal sulfide materials, and help to understand the biological effects of nanoparticles at the molecular level.
authors: School of Chemistry and Chemical Engineering, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Guangxi University for Nationalities, Nanning 530006, PR China. Electronic address: shtang5@163.com.
authors: Shihua
authors: S
authors: Tang
authors: School of Chemistry and Chemical Engineering, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Guangxi University for Nationalities, Nanning 530006, PR China.
authors: Baiyang
authors: B
authors: Wang
authors: School of Chemistry and Chemical Engineering, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Guangxi University for Nationalities, Nanning 530006, PR China.
authors: Youqun
authors: Y
authors: Li
mesh_terms: D000818:Animals; D019187:Cadmium Compounds / Q000737:chemistry / Q000378:metabolism*; D002417:Cattle; D005780:Gelatin / Q000378:metabolism*; D007700:Kinetics; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D013056:Spectrophotometry, Ultraviolet; D013440:Sulfides / Q000737:chemistry / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors
chemical_list: D019187:Cadmium Compounds; D013440:Sulfides; C034939:cadmium sulfide; D005780:Gelatin
keywords: Activation thermodynamic parameter; Differential method; Gelatin–CdS conjugate; Kinetics; Reaction rate equation