Our previous study reported the influences of different complexing agents on electroless nickel （EN） by examining the properties of the deposits. In the present work, the effects of four common-used complexing agent...Our previous study reported the influences of different complexing agents on electroless nickel （EN） by examining the properties of the deposits. In the present work, the effects of four common-used complexing agents on EN deposition rate and the stability of solution pH values were examined, either with an acetic pH buffer agent or absent of them. It is indicated that the pH buffeting effect of them is dominative when the EN solution is lack of the pH buffer. Under this situation, the EN deposition rate increases with the concentration of complexing agents increasing. The EN deposition rate decreases with fin＇ther adding the complexing agent when the solution already has enough pH buffer capability. Electrochemical impedance spectroscopy obtained during EN deposition illustrates that, in this case, the enhanced reaction resistance is the main reason for a lower deposition rate. However, the influence of polarization caused by mass transfer is not negligible at high complex ratio for sodium citrate and malic acid EN solutions.展开更多
The coordination complex Sm(C_(7)H_(5)O_(2))_(2)·(C_(9)H_(6)NO),synthesized from the reaction of samarium chloride sixhydrate with salicylic acid and 8-hydroxyquinoline,was characterized with IR,elemental analysi...The coordination complex Sm(C_(7)H_(5)O_(2))_(2)·(C_(9)H_(6)NO),synthesized from the reaction of samarium chloride sixhydrate with salicylic acid and 8-hydroxyquinoline,was characterized with IR,elemental analysis,molar conductance,and thermogravimatric analysis.The standard molar enthalpies of solution of[SmCl_(3)·6H_(2)O(s)],[2C_(7)H_(6)O_(3)(s)],[C_(9)H_(7)NO(s)]and[Sm(C_(7)H_(5)O_(3))_(2)·(C_(9)H_(6)NO)(s)]in the calorimetric solvent were determined with the solution-reaction isoperibol calorimeter at 298.15 K to be△sHm^-[SmC_(l3)·6H_(2)O(s),298.15 K]=-103.98±0.04 kJ·mol^(-1),△sHm^-[2 C_(7)H_(6)O_(3)(s),298.15 K]=16.35±0.14 kJ·mol^(-1),△sHm^-[C_(9)H_(7)NO(s),298.15 K]=-6.11±0.08 kJ·mol^(-1)and△sHm^-[Sm(C7H5O3)2·(C9H6NO)(s),298.15 K]=-130.08±0.04 kJ·mol^-1,respectively.The enthalpy was determined to be△rHm^-=89.59±0.18 kJ·mol^-1 for the reaction SmCl3·6H2O(s)+2C7H6O3(s)+C9H7NO(s)=Sm(C7H5O3)2·(C9H6NO)(s)+3HCl(g)+6H2O(l).According to the above results and the data given in literature and through Hess'law,the standard molar enthalpy of formation of Sin(C7H5O3)2·(C9H7NO)(s)was estimated to be△rHm^-[Sm(C7H5O3)2·(C9H6NO)(s),298.15 K]=-2055.9±3.03 kJ·mol^-1.展开更多
文摘Our previous study reported the influences of different complexing agents on electroless nickel （EN） by examining the properties of the deposits. In the present work, the effects of four common-used complexing agents on EN deposition rate and the stability of solution pH values were examined, either with an acetic pH buffer agent or absent of them. It is indicated that the pH buffeting effect of them is dominative when the EN solution is lack of the pH buffer. Under this situation, the EN deposition rate increases with the concentration of complexing agents increasing. The EN deposition rate decreases with fin＇ther adding the complexing agent when the solution already has enough pH buffer capability. Electrochemical impedance spectroscopy obtained during EN deposition illustrates that, in this case, the enhanced reaction resistance is the main reason for a lower deposition rate. However, the influence of polarization caused by mass transfer is not negligible at high complex ratio for sodium citrate and malic acid EN solutions.
基金Project supported by the Hunan Provincial Natural Sciences Foundation of China(03JJY3019)
文摘The coordination complex Sm(C_(7)H_(5)O_(2))_(2)·(C_(9)H_(6)NO),synthesized from the reaction of samarium chloride sixhydrate with salicylic acid and 8-hydroxyquinoline,was characterized with IR,elemental analysis,molar conductance,and thermogravimatric analysis.The standard molar enthalpies of solution of[SmCl_(3)·6H_(2)O(s)],[2C_(7)H_(6)O_(3)(s)],[C_(9)H_(7)NO(s)]and[Sm(C_(7)H_(5)O_(3))_(2)·(C_(9)H_(6)NO)(s)]in the calorimetric solvent were determined with the solution-reaction isoperibol calorimeter at 298.15 K to be△sHm^-[SmC_(l3)·6H_(2)O(s),298.15 K]=-103.98±0.04 kJ·mol^(-1),△sHm^-[2 C_(7)H_(6)O_(3)(s),298.15 K]=16.35±0.14 kJ·mol^(-1),△sHm^-[C_(9)H_(7)NO(s),298.15 K]=-6.11±0.08 kJ·mol^(-1)and△sHm^-[Sm(C7H5O3)2·(C9H6NO)(s),298.15 K]=-130.08±0.04 kJ·mol^-1,respectively.The enthalpy was determined to be△rHm^-=89.59±0.18 kJ·mol^-1 for the reaction SmCl3·6H2O(s)+2C7H6O3(s)+C9H7NO(s)=Sm(C7H5O3)2·(C9H6NO)(s)+3HCl(g)+6H2O(l).According to the above results and the data given in literature and through Hess'law,the standard molar enthalpy of formation of Sin(C7H5O3)2·(C9H7NO)(s)was estimated to be△rHm^-[Sm(C7H5O3)2·(C9H6NO)(s),298.15 K]=-2055.9±3.03 kJ·mol^-1.
