Double open mouse-like terpyridine parts based amphiphilic ionic molecules displaying strengthened chemical adsorption for anticorrosion of copper in sulfuric acid solution

In this study,the benign target double terpyridine parts based amphiphilic ionic molecules(AIMs 1,2)and the reference single terpyridine segment included AIMs(AIMs 3,4)were synthesized through a multi-step method,and the molecular structures were fully characterized.The excellent anticorrosion of the target AIMs for copper surface in H_(2)SO_(4) solution was demonstrated by the electrochemistry analysis,which was more superior over those of the reference AIMs.The standard adsorption free energy changes of the target AIMs calculated by the adsorption isotherms were lower than -40 kJ·mol^(-1),suggesting an intensified chemical adsorption on metal surface.The molecular modeling and molecular dynamic computation of the studied AIMs were performed,demonstrating that the target AIMs exhibited lower highest occupied molecular orbital-lowest unoccupied molecular orbital energy gaps and greater adsorption energies than the reference ones.The chemical adsorption of the AIMs on metal surface was revealed by various spectroscopic methods including scanning electron microscopy,atomic force microscopy,Fourier transform infrared spectroscopy,attenuated total reflection infrared spectroscopy,Raman and X-ray diffraction.

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.

Fractional nonlinear energy sinks

The cubic or third-power(TP)nonlinear energy sink(NES)has been proven to be an effective method for vibration suppression,owing to the occurrence of targeted energy transfer(TET).However,TET is unable to be triggered by the low initial energy input,and thus the TP NES would get failed under low-amplitude vibration.To resolve this issue,a new type of NES with fractional nonlinearity,e.g.,one-third-power(OTP)nonlinearity,is proposed.The dynamic behaviors of a linear oscillator(LO)with an OTP NES are investigated numerically,and then both the TET feature and the vibration attenuation performance are evaluated.Moreover,an analogy circuit is established,and the circuit simulations are carried out to verify the design concept of the OTP NES.It is found that the threshold for TET of the OTP NES is two orders of magnitude smaller than that of the TP NES.The parametric analysis shows that a heavier mass or a lower stiffness coefficient of the NES is beneficial to the occurrence of TET in the OTP NES system.Additionally,significant energy transfer is usually accompanied with efficient energy dissipation.Consequently,the OTP NES can realize TET under low initial input energy,which should be a promising approach for micro-vibration suppression.

Crude Extract of Detergent⁃Like Gleditsia sinensis lam Exhibiting Self⁃Organization for Protection of Mild Steel in Harsh Hydrochloric Acid Solution:How to Seek Crude Natural Plant Extracts as Green Corrosion Inhibitors

This study proposes a thought to employ detergent⁃like renewable low⁃cost crude extract of Gleditsia sinensis lam(GSL)as green corrosion inhibitor for mild steel in HCl solution.Crude Gleditsia sinensis lam extract(GSLE)was gained at mild conditions by simply refluxing in ethanol with a Soxhlet extractor.The target GSLE extract exhibited regular self⁃organization in mixed solvents of organic solvents/H2O such as ethanol/H2 O(v/v,50/50)at room temperature,which was evidenced by different means including scanning electron microscopy,transmission electron microscopy,and dynamic light scattering.The study demonstrates that the yielded assemblies of the crude extract of GSLE displayed chemical adsorption on the studied mild steel sample surfaces.Furthermore,the formed stable crude extract assemblies of GSL presented outstanding anti⁃corrosion capability in 1.0 mol/L HCl aqueous solution based on electrochemical measurements including polarization curves and impedance spectroscopy.It is discovered that the maximal corrosion inhibition efficiency could reach approximate 95%.The molecular modeling was performed to acquire the nature of frontier orbitals of the main representative chemical components of crude GSLE for deep understanding of chemical interactions with iron.The results presented herein would guide us to seek sustainable environmentally friendly low⁃cost detergent⁃like plant crude extracts for corrosion inhibition of various metals in aggressive acid environments.

New branched benign compounds including double antibiotic scaffolds:synthesis,simulation and adsorption for anticorrosion effect on mild steel

In this study,two novel environmental benign double antibiotic norfloxacin or ciprofloxacin scaffolds included branched molecules were prepared by multi-step routes and purified by simple performance,which were used as the target compounds(TCs).Meanwhile,a single norfloxacin or ciprofloxacin skeleton based molecules were synthesized as the reference compounds(RCs).The molecular geometry optimization and material simulation computation revealed that TCs presented smaller HOMOLUMO energy gaps and larger binding energy levels on mild steel surface than RCs.The chemical adsorption of TCs on steel surface was confirmed by X-ray photoelectron spectroscopy,which could be processed by TCs chelation with iron ions.It was shown that TCs could be self-adsorbed on steel surface,which was demonstrated by atomic force microscopy and scanning electron microscopy.The anticorrosion of the studied compounds for mild steel in HCl solution was investigated by electrochemistry analysis.The results suggested that the anticorrosion efficiency could reach 95.86%(TC1)and 97.05%(TC2)at 0.050 mmol·L^(−1) based on electrochemical impedance spectroscopy,which were much better than RCs(RC1,69.23%;RC2,74.16%).The adsorption isotherms of TCs on steel were further fitted,and a deep insight on adsorption was discussed.

High Performance Soft Electrochemical Actuators Based on Hierarchical Conductive Polymer Ionogels

Electrochemical actuators based on conductive polymers are emerging as a strong competitive in the field of soft actuators because of their intrinsically conformable/elastic nature,low cost,low operating voltage and air-working ability.Recent development has shown that adding electroactive materials,such as CNT and graphene,can improve their actuation performance.Despite the complex material systems used,their output strains(one of the key factors)are generally lower than 1%,which limited further applications of them in multiple scenarios.Here,we report soft electrochemical actuators based on conductive polymer ionogels by embedding polyaniline particles between the PEDOT:PSS nanosheets.Results show that such a hierarchical structure not only leads to a high conductivity(1250 S/cm)but also improved electrochemical activities.At a low operating voltage of 1 V,the maximum strain of these soft actuators reaches an exceptional value of 1.5%,with a high blocking force of 1.3 mN.Using these high-performance electrochemical actuators,we demonstrate soft grippers for manipulating object and a bionic flower stimulated by an electrical signal.This work sets an important step towards enabling the enhanced performance of electrochemical actuators based on conductive polymers with designed microstructures.

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.

Electroless copper plating using dimethylamine borane as reductant

Electroless copper plating was studied using dimethylamine borane(DMAB)as reductant and 1,5,8,12-tetraazadodecane as additive and triethanolamine(TEA)as buffer.The effects of pH,temperature and concentrations of reactants and additives on the anodic oxidation of DMAB and the cathodic reduction of copper ion were investigated.Experimental results indicate that high pH values(10-12.5)promote the oxidation of DMAB,and suppress the reduction of the copper ion,while high bath temperatures(55-70°C) accelerate both anodic oxidation and cathodic reduction.Increase of the Cu2+and DMAB concentrations can improve the deposition rate of copper plating.Results for a dual-chelating-agent system indicate that 1,5,8,12-tetraazadodecane plays an important role in chelation,while the main effect of TEA is adsorption on copper surfaces to inhibit DMAB oxidation and to promote deposition.