Co-reporter:Shuai Wang, Cunchuan Zheng, Jihe Zhao, Xiaojiang Li, Hongsheng Lu
Chemical Engineering Research and Design 2017 Volume 128(Volume 128) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.cherd.2017.09.036
•This provides a new environmental friendly approach to recycle diesel oil from waste oil-based cuttings.•Switchable hydrophilic solvent (SHS) was screened by the methods of CO2 absorption experiments and solubility.•SHS on the solubility of diesel can be more convenient through the solubility parameter model theoretically.•SHS showed a high recovery performance of diesel and itself.•SHS recovery process was consistent with the first-order kinetic and the activation energy of DMCHA was 30.37 kJ mol−1.Switchable hydrophilic solvent (SHS) has been developed as a green extractant for separate lipophilic substances. This article reported an efficient method to extract and recovery diesel in oil-based drill cuttings by using SHS. 1H NMR spectroscopy and pH measurement provided the possibility of SHS can be applied to the recovery of diesel. The screenings of SHS were carried out by CO2 absorption experiments and the solubility of SHS and diesel, which depended on the absorption rate and the solubility parameter model, respectively. The recovery process analyzed the reclaim performance of diesel and DMCHA. The dynamic analysis indicated that the process of DMCHA recovery was consistent with the first-order kinetic, and proved the conclusion of the influence of temperature and aeration rate on DMCHA recovery. Ultimately, the rate constant was used to obtain the DMCHA recovery activation energy of 30.37 kJ mol−1, which provided a reference for the study of low energy consumption. All above studies provided guidance for the design of recycling diesel oil in oil-based drill cuttings by SHS, and therefore, it can achieve the safety and environmental protection of oil-based drill cuttings.
Co-reporter:Dongfang Liu;Yuxin Suo;Jiang Tan
Soft Matter (2005-Present) 2017 vol. 13(Issue 20) pp:3783-3788
Publication Date(Web):2017/05/24
DOI:10.1039/C7SM00576H
At present, more and more researchers around the world are paying attention to stimuli-responsive surfactants. In this paper, we have reported a microemulsion prepared from the tertiary amine TMPDA (N,N,N′,N′-tetramethyl-1,3-propanediamine) and the anionic surfactant SDS (sodium dodecyl sulphate), which has good carbon dioxide response characteristics. The molar ratio of TMPDA to SDS is 1 : 2. By introducing CO2 into the microemulsion that consists of SDS, TMPDA, n-hexane, n-butanol and water, the tertiary amine TMPDA molecules can be protonated to form quaternary ammonium species. The protonated tertiary amine TMPDA can be assembled with SDS by electrostatic interactions to form a pseudogemini surfactant (SDS–TMPDA–SDS). The pseudogemini surfactant can dissolve in the aqueous phase which makes the microemulsion break down eventually. By bubbling N2 after CO2 into the same system at 50 °C for 3 hours, the pseudogemini surfactant SDS–TMPDA–SDS disintegrates into SDS and TMPDA, respectively. At the same time, the microemulsion also recovers its initial state. Such a reversible transition could be repeated for several cycles from monophase to complete phase separation.
Co-reporter:Baogang Wang, Weiwei Tang, Hongsheng Lu and Zhiyu Huang
Journal of Materials Chemistry A 2016 vol. 4(Issue 19) pp:7257-7265
Publication Date(Web):30 Mar 2016
DOI:10.1039/C6TA01098A
Ionic liquid (1-aminopropyl-3-methyl-imidazolium bromide) capped carbon dots (CDs-Br), with a mean particle size of 1.73 nm and poor crystallinity, have been successfully synthesized by a one-pot pyrolysis method. The CDs-NTf2 were obtained from the CDs-Br by an anion exchange reaction between Br− and N(CF3SO2)2− (NTf2−). The NTf2− endowed the CDs-NTf2 with wonderful dispersion stability in poly(ethylene glycol) (PEG). The tribological performances of CDs-NTf2 as the lubricant additive for PEG were investigated in detail using a four-ball model by altering the concentration of CDs-NTf2, the test load and the duration. The results demonstrated that these CD-NTf2-based additives exhibited excellent friction-reducing and antiwear properties. In particular, the friction coefficient and wear scar diameter (WSD) of lower balls lubricated by PEG under 392 N correspondingly reduced by 70% and 33% when 0.3 wt% of CDs-NTf2 was introduced. The WSD reduction further increased by 45% when the test load was increased to 600 N. Moreover, the CD-NTf2-based additives could work for a long time without weakening the lubrication capabilities. The lubricating mechanism of CD-NTf2-based additives has also been proposed and illustrated that the synergistic lubricating effect of CDs-NTf2, including film lubrication of IL groups and nano-lubrication of carbon cores such as rolling, mending and polishing effects, might account for their outstanding tribological behaviors. The above results indicate that CDs are expected to be utilized as a kind of designable and high-performance lubricant additive and find wide applications in machinery and equipment.
Co-reporter:Hongsheng Lu, Qianping Shi, Baogang Wang, Zhiyu Huang
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2016 Volume 494() pp:74-80
Publication Date(Web):5 April 2016
DOI:10.1016/j.colsurfa.2016.01.014
•The pseudogemini surfactant system is pH-responsive.•The two types of pH-responsive groups in this pseudogemini surfactant system both worked for the micelle transition.•Viscosity of the pseudogemini surfactant system can be promptly regulated by pH.•The low-high-low viscosity variation can be reversibly switched at least 3 cycles of pH regulation.A novel pseudogemini surfactant system, which has two types of pH-responsive groups in the connection of the alkyl chain and the spacer, has been developed and investigated by adjusting pH. These two types of pH-responsive groups both worked for the micelle transition because they had different ionization degrees and electrostatic attraction forces with the aid of pH variation. The system could be promptly switched between low viscosity fluid and high viscoelastic solution. Besides, the pH-responsive ability was studied by the steady and dynamic rheological measurements, which is effective after several cycles of pH adjusting with the almost invariable magnitude level of viscosity. The transition between spherical micelle and wormlike micelle for the surfactant system at different pH values could be further confirmed by dynamic light scattering and cryogenic transmission electron microscopy characterization.
Co-reporter:Hongsheng Lu;Ya Liu;Jifeng Jiang;Zhiyu Huang
Journal of Applied Polymer Science 2015 Volume 132( Issue 7) pp:
Publication Date(Web):
DOI:10.1002/app.41468
ABSTRACT
A series of copolymers, poly(acrylamide)-co-poly(N,N-dimethylaminoethyl methacrylate)-co-poly(N-cetyl DMAEMA) (abbreviation PDAMCn), was synthesized with different monomer ratios. The resulting copolymer solution shows pronounced viscosity–response property which is CO2-triggered and N2-enabled. Electrical conductivity experiment shows that tertiary amine group on DMAEMA experiences a protonate and deprotonate transition upon CO2 addition and its removal. In addition, different incorporation rates of DMAEMA leads to two kinds of morphological change in the presence of CO2 and thus induces different rheological behaviors. PDAMCn incorporating longer hydrophobic monomer (C18DM) show more pronounced initial viscosity and higher critical stress required to cause network deformation, which consequently enhances the viscosity–response property of the solution. The addition of NaCl could also tune the viscosity of PDAMCn solution. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41468.
Co-reporter:Baogang Wang;Weiwei Tang;Zhiyu Huang
Journal of Materials Science 2015 Volume 50( Issue 16) pp:5411-5418
Publication Date(Web):2015 August
DOI:10.1007/s10853-015-9085-y
Ionic liquid (1-aminopropyl-3-methyl-imidazolium bromide, [APMIm][Br])-capped carbon quantum dots (CQDs) were obtained by a hydrothermal method. Characterization results demonstrated that the CQDs possessed an average particle size of 2.9 nm, poor crystallinity, and [APMIm][Br] shell linked by amide bond. In addition, the CQD surfaces were also decorated by some oxygen-containing groups. These surface groups made CQDs have an excellent dispersibility in water. The optical property measurements indicated that CQDs aqueous suspension emitted strongest blue fluorescence at 443 nm under 375 nm excitation with a fluorescence quantum yield of 20.3 %. The luminescence property of CQDs in water exhibited excitation wavelength-, concentration-, and pH-dependences, high photostability, and outstanding salt resistance. More importantly, the [APMIm][Br] shell endowed CQDs with a high thermal stability (>300 °C) and an interesting anion responsiveness, i.e., CQDs spontaneously transferred from aqueous phase to ethyl acetate phase once the anion of N(CF3SO2)2− was introduced. These particular properties should provide more possibilities for the utility of CQDs in various fields.
Co-reporter:Hongsheng Lu, Li Wang and Zhiyu Huang
RSC Advances 2014 vol. 4(Issue 93) pp:51519-51527
Publication Date(Web):12 Sep 2014
DOI:10.1039/C4RA08004A
A novel pH-responsive viscoelastic micellar system was prepared by N,N-dimethyl oleoaminde-propylamine without the addition of hydrotropes. The micellar system undergoes a gradual transition from vesicles to spherical micelles to wormlike micelles by adding an HCl solution. Rheology, Cryo-TEM and dynamic light scattering (DLS) results revealed that the pH-responsive flow behavior is attributed to the microstructural transition among the spherical micelles, vesicles and worm-like micelles. In this paper, we found out that a vesicle is extremely pH sensitive because the degree of protonation and the concentration of Cl− strongly affect the pH areas which could form worm-like micelles. The notable advantages of vesicles and worm-like micelles can be utilized to prepare pH-responsive viscoelastic fluids in the desired pH areas.
Co-reporter:Hongsheng Lu;Jifeng Jiang;Zhiyu Huang;Shanshan Dai
Journal of Applied Polymer Science 2014 Volume 131( Issue 19) pp:
Publication Date(Web):
DOI:10.1002/app.40872
ABSTRACT
A series of copolymers PDAMs were synthesized with varying monomer ratio of acrylamide (AM) and N,N-dimethylaminoethyl methacrylate (DMAEMA). The resulting copolymer solution shows an interesting property of viscosity-response which is CO2-triggered and N2-enabled. Tertiary amine groups of PDAMs experience a reversible transition between hydrophobic and hydrophilic state upon CO2 addition and its removal, which induced different rheological behavior. A combination of zeta-potential, laser particle-size analysis, and electrical conductivity analysis indicated that, when the monomer mole ratio of DMAEMA and AM is less than or equal to 3 : 7, the hydrophobic association structure between the copolymer molecules was destroyed by the leading of CO2 and caused a viscosity decrease in its solution. On the contrary, when the monomer mole ratio of DMAEMA and AM is more than 3 : 7, a more extended conformation due to the protonated tertiary amine groups is formed and the enhanced repulsive interactions among the copolymer molecule results in a rise of its solution viscosity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40872.
Co-reporter:Hongsheng Lu, Qianping Shi, and Zhiyu Huang
The Journal of Physical Chemistry B 2014 Volume 118(Issue 43) pp:12511-12517
Publication Date(Web):October 13, 2014
DOI:10.1021/jp506809m
A pH-responsive anionic surfactant wormlike micellar system induced by NaCl has been developed. In this work, the anionic surfactant, sodium oleate (NaOA) solutions, transforms from low-viscosity fluid into high-viscoelastic solution induced by NaCl of 200 mM to 350 mM concentration. According to the above, the solution reversibility has been studied via changing pH value of the solution. This pH-responsive solution can be promptly switched between gel-like solution and waterlike fluid in a narrow pH value range. Steady and dynamic rheological measurements are employed to characterize the pH-responsiveness at different pH. The transformation between wormlike micelle and spherical micelle in the various pH solutions is demonstrated by dynamic light scattering tests, cryo-TEM, and NMR measurements. The pH-responsive property of the system is attributed to the carboxylate ion contained by sodium oleate. With higher pH value, the ionized carboxylate combines with NaCl closely and thus forms wormlike micelles. On the contrary, sodium oleate converts to oleate acid when pH decreases. In this way, spherical micelles are transformed because of the weaker interaction between oleate aicd and NaCl.
Co-reporter:Hongsheng Lu, Cunchuan Zheng, Miao Xue and Zhiyu Huang
Physical Chemistry Chemical Physics 2016 - vol. 18(Issue 47) pp:NaN32197-32197
Publication Date(Web):2016/11/01
DOI:10.1039/C6CP06599F
A zwitterionic gemini surfactant, called 2,2′-(1,4-phenylenebis(oxy))bis(N,N-dimethyl)-N-carboxyethyl-N-(alkylamide propyl) ammonium chloride (C14–B–C14), was synthesized successfully. The surfactant molecule exhibits various states at different pH values due to the two pH-sensitive carboxylate groups in the molecule. The surface activity and aggregate behaviors of C14–B–C14 in the aqueous solution were investigated under different pH conditions. The surface activities of the surfactant decrease with the increase in pH due to higher hydrophilic properties under basic conditions. The aggregate behaviours were also studied in acidic, near neutral and alkaline solutions, respectively. When the pH values of the solutions increased from acidic conditions to near neutral conditions (6.80), the samples immediately transformed from water-like solutions to viscoelastic fluids and remained gel-like under basic conditions. The changes in the appearance of the solution were due to the transition of the micelle structure from spherical to worm-like. Furthermore, this transition was reversible and repeated for at least 4 cycles. Finally, a reasonable mechanism of the appearance and transition of micelles was proposed based on the molecular states, viscoelastic properties and micelle structures.
Co-reporter:Baogang Wang, Weiwei Tang, Hongsheng Lu and Zhiyu Huang
Journal of Materials Chemistry A 2016 - vol. 4(Issue 19) pp:NaN7265-7265
Publication Date(Web):2016/03/30
DOI:10.1039/C6TA01098A
Ionic liquid (1-aminopropyl-3-methyl-imidazolium bromide) capped carbon dots (CDs-Br), with a mean particle size of 1.73 nm and poor crystallinity, have been successfully synthesized by a one-pot pyrolysis method. The CDs-NTf2 were obtained from the CDs-Br by an anion exchange reaction between Br− and N(CF3SO2)2− (NTf2−). The NTf2− endowed the CDs-NTf2 with wonderful dispersion stability in poly(ethylene glycol) (PEG). The tribological performances of CDs-NTf2 as the lubricant additive for PEG were investigated in detail using a four-ball model by altering the concentration of CDs-NTf2, the test load and the duration. The results demonstrated that these CD-NTf2-based additives exhibited excellent friction-reducing and antiwear properties. In particular, the friction coefficient and wear scar diameter (WSD) of lower balls lubricated by PEG under 392 N correspondingly reduced by 70% and 33% when 0.3 wt% of CDs-NTf2 was introduced. The WSD reduction further increased by 45% when the test load was increased to 600 N. Moreover, the CD-NTf2-based additives could work for a long time without weakening the lubrication capabilities. The lubricating mechanism of CD-NTf2-based additives has also been proposed and illustrated that the synergistic lubricating effect of CDs-NTf2, including film lubrication of IL groups and nano-lubrication of carbon cores such as rolling, mending and polishing effects, might account for their outstanding tribological behaviors. The above results indicate that CDs are expected to be utilized as a kind of designable and high-performance lubricant additive and find wide applications in machinery and equipment.
![1-Hexadecanaminium,N,N-dimethyl-N-[2-[(2-methyl-1-oxo-2-propenyl)oxy]ethyl]-, bromide](http://img.cochemist.com/ccimg/58800/58710-34-2.png)
![1-Hexadecanaminium,N,N-dimethyl-N-[2-[(2-methyl-1-oxo-2-propenyl)oxy]ethyl]-, bromide](http://img.cochemist.com/ccimg/58800/58710-34-2_b.png)
![2-UNDECYL-1-[2-(2-UNDECYL-4,5-DIHYDROIMIDAZOL-1-YL)ETHYL]-4,5-DIHYDROIMIDAZOLE](http://img.cochemist.com/ccimg/53700/53609-09-9.png)
![2-UNDECYL-1-[2-(2-UNDECYL-4,5-DIHYDROIMIDAZOL-1-YL)ETHYL]-4,5-DIHYDROIMIDAZOLE](http://img.cochemist.com/ccimg/53700/53609-09-9_b.png)
