硬脂酸钠在蓖麻油/水界面上自组装动力学的研究

Self Assemblying Kinetics of Sodium Steareate at Castor Oil/Water Interface

以电沉积铜为探针,循环伏安法研究硬脂酸钠在蓖麻油/水界面上自组装的动力学.在涂有蓖麻油的石墨粉-环氧树脂固态电极上,硬脂酸钠自组装膜形成过程可由电沉积铜阳极峰监测,遵从高斯函数生长动力学,生长速率常数为km=0.0006292(±0.0000294)s-1.硬脂酸钠自组装膜能较好地控制铜粒子的球形生长和生长尺度,形成硬脂酸钠自组装-铜纳米粒子复合膜.铜粒子在石墨粉-环氧树脂固态电极上为半球形生长,而在涂油和自组装电极上为球形生长.与蓖麻油涂层相比,石墨粉-环氧树脂固态电极与沉积铜间存在弱相互作用(ΔG0=3.86kJ/mol),而硬脂酸钠羧基与沉积铜也有较弱的相互作用(ΔG0=-2.412kJ/mol).

The self assembly membrane （SAM） formation kinetics of sodium stearate at castor oil/water interface was studied by cyclic voltammetrry. At caster oil coated graphite-epoxy solid electrode surface, the SAM grows according to the Gaussian growth function with a rate constant of km= 0. 0006292 （0.0000294） s^-l, and maximum particle size at to = 3127s. The SAM of sodium stearate controls the growth and particle size of the deposited copper nano particles well, and forms a composite membrane of the SAM and copper nano particle. The growth mechanism of copper particle at oiled electrode or SAM modified oiled electrode is spherical growth, while it is the semi-spherical growth at bared graphite-epoxy solid phase electrode. Compared with castor oil coated electrode, the deposited copper particles show the stronger interaction to graphite-epoxy solid phase electrode surface with the free energy change of △G^o = 3.86 kJ/mol and a weaker interaction to the SAM of sodium stearate with the free energy change of △G^o =-2. 412 kJ/mol.