Thermodynamic and optical properties of HCOOH(H2O)n and HCOOH(NH3)(H2O)(n-1) clusters at various temperatures and pressures: a computational study

Density functional theory has been used to compute the gas-phase geometries, binding energies, ZPE-corrected binding energies, BSSE-corrected binding energies, binding enthalpies, and binding free energies of HCOOH(H₂O)_n and HCOOH(NH₃)(H₂O)_(n-1) clusters with n = 1-8, 10, 12, 14, 16, 18, and 20. Enthalpies and free energies are calculated for a range of atmospherically relevant temperatures (T) and pressures (P) (from T = 298.15 K, P = 1013.25 hPa to T = 216.65 K, P = 226.32 hPa). The optical properties of those clusters have been studied at the CAM-B3LYP/aug-cc-pVDZ level of theory.

Improving Corrosion Protection and Friction Resistance of Q235 Steel by Combining Noncovalent Action and Rotating Coating Method

Developing waterborne epoxy (WEP) coatings with excellent corrosion resistance and tribological properties is a key aspect to solve the damage of Q235 steel. In this work, perylene bisimide (PBI) derivatives dispersion graphene (GR) were prepared by a π-π stacking, the highly orientated PBI0.5%/GR0.5%/WEP coating will be prepared by the rotating coating method. Especially, the impedance value reached about 109 Ω·cm2 when the PBI and GR ratio is 1:1. The impedance value of PBI0.5%/GR0.5%/WEP coating increased by 3 orders of magnitude compared with that of pure WEP coating (106 Ω·cm2). Additionally, the coefficient of friction of the coatings was 0.33; compared with that of WEP, the coefficient of friction decreased by 48%, and the wear resistance increased by 87.6%. The results show that the PBI0.5%/GR0.5%/WEP coatings exhibited excellent corrosion resistance and wear resistance properties due to the good dispersion and high orientation of PBI/GR in WEP. It is anticipated that our current work would guide the ongoing efforts to develop a more efficient method to overcome the poor dispersion of GR in waterborne epoxy resin and provide a green coating with excellent corrosion resistance and wear resistance properties.