A CO_(2)-controllable phase change absorbent solvent used to waste recycling of dining lampblack

Dining lampblack as a source of atmospheric pollution,urban residents had to spend a lot of economic costs all year round to solve its impact.However,traditional treatment methods often carry the risk of secondary pollution.The use of phase change absorption solvent(PCAS)controlled by CO_(2)can effectively absorb the oily components in dining lampblack,and smoothly avoid the generation of secondary pollutants and squandering of resources.The reversibility of PCASs under CO_(2)control was explained by pH changes and macroscopic visualizations.The absorption effects of favorable absorbents and PCASs on dining lampblack were compared and analyzed.The fatty acid(FA)in the oil absorption mixture was desorbed by interacting with D230.The results of GC/MS analysis on the oil components separated by desorption showed that the desorption of PCASs was effective for these refractory oil components.FAs can be enriched and applied to the subsequent dining lampblack treatment link to realize the waste recycling.In addition,the absorption and desorption of oily components by PCASs were combined with the CO_(2)-controlled phase transformation of PCASs itself to achieve the absorption circulation of treating dining lampblack by using PCASs.

Ratcheting Behavior of Weld Joints Under Uniaxial Cyclic Loading Using Miniature Specimen

Because of the size limitation of weld joints in different regions, the traditional standard bar specimen is not suitable to investigate the mechanical properties of weld joints. In this study, miniature specimens were extracted from specific regions(base metal, weld metal, and three heat-affected zones) of API X80 and X70 weld joints. Uniaxial tensile tests were conducted to obtain the mechanical properties of different regions, and then uniaxial ratcheting tests were conducted to investigate the ratcheting behaviors of the different regions under the same peak and nominal stresses. Under both the tensile tests and ratcheting tests, the weld joints exhibit heterogeneous results, such as different mechanical properties and ratcheting behaviors, which were region dependent. Furthermore, the yield strength and yield-to-tensile strength ratio contribute differently to the ratcheting response.

Astonishingly distinct lubricity difference between the ionic liquid modified carbon nanoparticles grafted by anion and cation moieties

The astonishingly distinct lubricity difference between the ionic liquid modified carbon nanoparticles grafted by anion and cation moieties(A-g-CNPs and C-g-CNPs)was well established as additives of polyethylene glycol(PEG200).The peripheral anion moieties and positively charged inner parts of C-g-CNPs could successively absorb onto the friction interfaces by electrostatic interactions to form the organic-inorganic electric double layer structures,tremendously boosting the lubricity of PEG200.Contrarily,the preferentially electrostatic adsorption of negatively charged inner parts but repulsion of the peripheral cation moieties determined the weak embedded stability of A-g-CNPs between the friction interfaces,even impairing the lubricity of PEG200.This work can offer solidly experimental and theoretical guidance for designing and developing the high-performance nanoadditives modified by ionic molecules.

Treating oily solids using a CO_(2)-responsive surfactant-free microemulsion:An enhanced approach for oil removal from solid surfaces

Because switchable water is difficult to apply directly for oil removal,an enhanced approach to improve oil removal is proposed using a surfactant-free microemulsion(SFME)containing switchable water.The SFME is formed using switchable water(aqueous N,N-dimethylethanolamine(DMEA)or N,N-dimethylbutylamine(BDEA))and a hydrophobic amine(N-butyldiethanolamine(DMBA)).The single-phase region for preparing the SFME is determined using a ternary phase diagram,and the microstructure types are distinguished using the con-ductivity method.The pH changes and dynamic laser scattering test results demonstrate that the SFME exhibits irreversible transformation behavior regulated by CO_(2).Moreover,the recovered SFME containing BDEA has a microstructure with a smaller particle size after removing the CO_(2) by bubbling N 2 at 65°C,which is attributed to the higher proportion of DMEA than that of BDEA.In addition,dodecane and diesel oil are shown to dissolve in the SFME,and the oil solubility of the SFME increases with increasing oil phase(DMBA)content.The interface free energy theory reveals that the oil is more easily detached with the addition of SFME than with switchable water only owing to the reduced interface free energy of oil on the solid surface.Thus,an enhanced approach for removing oil is proposed to wash oil sands,where the oil removal efficiency of switchable water can be improved by using SFMEs containing switchable water.