Enhanced adsorption of target branched compounds including antibiotic norfloxacin frameworks on mild steel surface for efficient protection: An experimental and molecular modelling study

In this study, an approach was proposed to employ new target branched compounds(TBCs) including multiple antibiotic norfloxacin frameworks for intensified adsorption films to achieve super protection of mild steel in HCl medium. Thus, the TBCs containing bis/tri norfloxacin skeletons were synthesized by multi-step preparation route. In addition, the reference linear compound(RLC) including a single norfloxacin part was also synthesized. The chemical structures of these compounds were confirmed by various means. It was demonstrated that the TBCs could form the tough adsorption films on the surface of mild steel, which could be processed mainly through chemisorption effect. The electrochemical analysis suggested that the TBCs displayed superior corrosion inhibition performance for low carbon steel in1.0 mol·L^(-1) HCl solution over the RLC(RLC, 87.80%;TBC1, 97.63%;TBC2, 98.35%), which was further understood by the molecular modelling. The isotherm adsorption plots were employed to analyze the spontaneous adsorption process of the TBCs on low carbon steel surface, and a prominent chemisorption could be inferred by the standard Gibbs free energy changes of the adsorption.

A diluent protective organic additive electrolyte of hydrophilic hyperbranched polyester for long-life reversible aqueous zinc manganese oxide batteries

hydrophilic hyperbranched polyester(poly(tetramethylol acetylenediurea(TA)-CO-succinyl chloride)(PTS))was proposed to be used as an organic additive in aqueous ZnSO_(4)electrolyte to achieve a highly reversible zinc/manganese oxide battery.It is found that the zinc symmetric battery based on the 2.0 wt.%PTS/ZnSO_(4)electrolyte showed a long cycle stability of more than 2400 h at 1.0 mA·cm^(-2),which is much longer than that including the blank ZnSO_(4)electrolyte(140 h).Furthermore,the capacity retention of the Zn||MnO_(2)full cells employing the 2.0 wt.%PTS/ZnSO_(4)electrolyte remained 85%after 100 cycles at 0.2 A·g^(1),which is much higher than 20%capacity retention of the cell containing the blank ZnSO_(4)electrolyte,and also greater than 59.6%capacity retention of the cell including the 10.0 wt.%TA/ZnSO_(4)electrolyte.By using 2.0 wt.%PTS/ZnSO_(4)electrolytes,the capacity retention of the Zn||MnO_(2)full cells even reached 65%after 2000 cycles at a higher current density of 1.0 A·g^(1).It is further demonstrated that the PTS was firmly adsorbed on the zinc anode surface to form a protective layer.