Synergistic Effect of i-C3F7CN/CO2 and i-C3F7CN/N2 Mixtures

In order to study the synergistic effect of i-C
₃
F
₇
CN mixtures, were carried out the power frequency breakdown experiments on 5%-20% i-C
₃
F7CN/CO
₂
and i-C
₃
F
₇
CN/N
₂
mixtures in uniform electric fields with pressures ranging from 0.1 to 0.7 MPa. Based on density functional theory (DFT), the configurations of single molecular and bimolecular complexes were established and optimized using the M06-2X-D3/6-311G(d, p) method. Also, the total energy, interaction energy, and bond energy of the molecules or complexes were obtained using M06-2X-D3/6-311+G(d, p) method. The experimental and computational results show that the power frequency breakdown fields of i-C
₃
F
₇
CN/CO
₂
and i-C
₃
F
₇
CN/N
₂
mixtures increase linearly with pressure. In the range of 0.1-0.2 MPa, the synergistic effect of the i-C
₃
F
₇
CN mixtures enhances as the i-C
₃
F
₇
CN proportion increases, and the synergistic effect of i-C
₃
F
₇
CN/CO
₂
mixture is more significant than that of i-C
₃
F
₇
CN/N
₂
mixture. The interaction energy between the complexes of i-C
₃
F
₇
CN...CO
₂
is -7.36 kJ/mol, which is stronger than -3.09 kJ/mol of the complexes of i-C
₃
F
₇
CN...N
₂
. The results show that there is a correlation between the synergistic effect of i-C
₃
F
₇
CN mixtures and the intermolecular interaction of i-C
₃
F
₇
CN bimolecular complexes. The synergistic effect of i-C
₃
F
₇
CN mixtures can be analyzed by calculating the interaction between i-C
₃
F
₇
CN and the molecular structure of buffer gases.