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Background and Objective: The effects of representative solder flux residue weak organic acids on electrochemical migration (ECM) of tin in thin electrolyte layer were studied using a technique based on the coupling of in situ electrochemical measurements and optical observations, as well as ex situ characterizations. Methods and Results: The results showed that the increasing amount of weak organic acid decreased the probability of ECM and dendrites formed were mainly composed of metallic tin. Tin ions reacted with organic compound ions from hydrolysis of weak organic acids to form complexes with electronegativity, which retarded the transfer of tin ions. Some complexes can be oxidized to the insoluble tin oxides on the anode surface and blocked the dissolution of anode during tin ECM. Conclusion: The growth rate of tin dendrite was found to be limited by the dissociation of complexes. Mechanisms involved were proposed to explain the role of weak organic acid in the tin ECM.

Supplemental material, sj-pdf-1-pac-10.1177_18344909211010514 for Psychological Capital, Positive Affect, and Organizational Outcomes by Shu Da, Ze Zhu, Hongyu Cen, Xianmin Gong, Oi Ling Siu and Xichao Zhang in Journal of Pacific Rim Psychology

Corrosion behavior of Sn-3.0Ag-0.5Cu lead-free solder alloy under chlorine-containing thin electrolyte layers is studied. The emphasis is laid on discussion about influences of addition of alloying elements, concentration of chloride ion and thickness of electrolyte layer on its corrosion behavior. Results indicate that: mainly local corrosion occurs to the alloy; Existence of intermetallic compounds and β-Sn crystal boundary facilitates the process of Cl− infiltration into the base and galvanic corrosion. Metal ions are accumulated in pitting corrosion region, and hydrolysis of metallic ions promotes the solution acidification and transverse development of pitting corrosion.

As the scientific problems aroused in the aspects of interface behavior, colloidal properties and material structures, the novel nano-inhibitors have attracted a lot of attention gradually. Given the diversity of nanomaterials and their structures, the investigations about the inhibition mechanisms of nano-inhibitors besides the traditional adsorption are conducive to improving the basic research of inhibitors discipline system. In this study, N, S co-doped carbon coated MnS/MnO/Mn nanoparticles (MnS/MnO/Mn@SNC) were synthetized via the sol-gel method and later pyrolysis-sulfurization/oxidation. Diversified measurements have been adopted to investigate the inhibition performance of MnS/MnO/Mn@SNC for carbon steel in CO2-saturated 3 wt% NaCl solution, and the results confirmed that MnS/MnO/Mn@SNC can effectively inhibit corrosion, while the inhibition efficiency was more than 90% at 200 mg/L. The various immersion time and addition concentration have been applied to analyze the differences of inhibition effect. From the observation and analysis of surface, lamellar nanomaterials containing the simple substance of Mn have accumulated at interface along with the transformation from MnS to FeS, which were respectively served as anode material and dense corrosion product to protect the carbon steel. Besides that, the accumulations of carbon complex material have formed a hydrophobic film with special micro-nano structures. The probable model of MnS/MnO/Mn@SNC on metal surface was established to discuss the actual inhibition mechanism.

Functionalized graphene oxide (FGO) were synthesized and investigated as corrosion inhibitors of carbon steel in this research. The inhibition behavior of FGO in CO2-saturated NaCl solution was studied via weight loss, surface characterizations, and electrochemical measurements. Results confirm that FGO could protect metal effectively and the inhibition efficiency showed the extreme effect as the increase of FGO concentration, reaching a maximum of 83.4% at 20 mg/L. FGO can adsorb on carbon steel via the functionalized groups and form the hydrophobic cover layer on the metal surface by the lamellar nanoparticles.

Psychological capital (PsyCap) is a higher-order construct comprising hope, efficacy, optimism, and resiliency, which has attracted more and more attention from both academics and practitioners. Despite promising progress made in the PsyCap literature, the underlying mechanisms linking PsyCap to organizational outcomes still need more investigation utilizing longitudinal research design. Moreover, the reciprocal relationships between PsyCap and positive affect require more attention. Therefore, we aim to test the central role of positive affect in the relationships between PsyCap and affective organizational commitment (AOC) on one hand and organizational citizenship behaviour toward organization (OCBO) on the other hand as well as the reciprocal relationships between PsyCap and positive affect in this study. A three-wave longitudinal survey was conducted using a cross-lagged panel design with a one-month time lag between two consecutive waves. Panel data was collected from 208 workers in Beijing, China. The results support the hypothesis that positive affect serves as a mediator in the relationships between PsyCap and OCBO. Moreover, we also find some support for a reciprocal relationship between PsyCap and positive affect. The theoretical and practical implications of the findings are also discussed.

Functionalized carbon nanotubes (FCNTs) were synthesized by hydrothermal method and adopted as a corrosion inhibitor of carbon steel in CO2-saturated NaCl solution. Results revealed that FCNTs can effectively inhibit carbon steel corrosion, and their inhibition efficiency is close to 90 % at the concentration of 100 mg L−1. FCNTs can adsorb on carbon steel via functionalized groups and make up the hydrophobic layer on the metal surface, which also inhibits the diffusion migration of corrosive mediums as confirmed by molecular dynamics simulation. Adsorption kinetic and thermodynamic isotherm were studied to discuss the difference of FCNTs with traditional inhibitors.

Cu-based metal–organic framework materials (Cu-MOFs) were synthesized by reacting copper nitrate trihydrate with 5-methyl-2-thiophenecarboxylic acid in the presence of 4,4-bipyridyl via the solvothermal method, and the structure of the resulting materials was characterized. The experimental results showed that Cu-MOFs could significantly reduce the corrosion rate of carbon steel and protect it from corrosion. Increasing the concentration of Cu-MOFs in the test solution increased inhibition efficiency, which reached 82.42% at 50 mg/L Cu-MOFs. Our findings confirmed that the synthesized Cu-MOFs could adsorb into and cover the surface of carbon steel to form a dense protective film that inhibits its corrosion.

N and S co-doped carbon dots (N, S-CDs) were first adopted as a corrosion inhibitor for aluminium alloy. The inhibition behavior of N, S-CDs for 5052 aluminium alloy in HCl solution was studied via weight loss, surface characterizations, and electrochemical measurements. Results confirm that N, S-CDs could protect aluminium effectively and the inhibition efficiencies reached 85% even at 5 mg L−1. N, S-CDs could adhere to the aluminium surface through the diffusion and agglomeration effect of nanomaterials, and the interaction between aluminium ions and N, S-CDs results in the formation of a reticular resist film on an aluminium surface.