Shiling Yuan

Shandong University, Chi-nan-shih, Shandong Sheng, China

Are you Shiling Yuan?

Claim your profile

Publications (53)130.41 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The aggregation behaviors of two trisiloxane-tailed surface active ionic liquids in water have been investigated by coarse-grained (CG) molecular dynamics simulation on the basis of MARTINI force field. The new CG model is developed from the optimized molecule computed by using density functional theory. Direct comparison of angles and bonds obtained from all-atom (AA) simulations with those calculated from the CG model has been conducted to validate the latter model. Excellent agreement between AA and CG demonstrates that the potential of the new CG model can represent the complex system well. The long time CG simulation has been performed to understand the formation process of micelles when dissolving ionic liquids in water. Vesicles were observed at the final stage of the simulation and their partially truncated views and density profiles were obtained to describe the structure in detail.
    Journal of Dispersion Science and Technology 11/2014; 35(11). DOI:10.1080/01932691.2013.856319 · 0.71 Impact Factor
  • BaoShuo Li, ShiLing Yuan
    [Show abstract] [Hide abstract]
    ABSTRACT: The TiMgAlCu mixed oxides, based on hydrotalcite-like compounds, was developed as novel SOx removal catalysts for FCC (fluid catalytic cracking) process. The mixed oxides were prepared by modified co-precipitation method and estimated for SOx removal under conditions similar to those of FCC units. XRD, TG/DTA and N2 adsorption analysis were performed to investigate the physicochemical and textural properties of the samples. The analysis results indicated that all the samples exhibit good dispersion of metal oxides in the matrix. The SOx adsorption–reduction tests showed that the novel TiMgAlCu catalysts with 15%Ti and 1% Cu had a good performance on SOx removal. Moreover, the particle size had obvious effect on the adsorption activity of sulfur remove catalysts and the best fit particle size is from 100 to 300 μm.
    Ceramics International 09/2014; 40(8):11559–11566. DOI:10.1016/j.ceramint.2014.03.112 · 2.09 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Two kinds of carbon materials,i.e., graphene and graphene oxide (GO), were successfully incorporated into a lyotropic liquid crystal (LLC) matrix formed by n-dodecyl tetraethylene monoether (C12E4). The properties of graphene/C12E4 and GO/C12E4 LLC composites were characterized by UV-vis absorption, transmission electron microscopy (TEM) observations, polarized optical microscopy (POM) observations, small-angle X-ray scattering (SAXS) and rheological measurements. SAXS results indicate that both graphene and GO are well-dispersed in the C12E4 LLC matrix and some interactions occur between C12E4 LLC matrix and graphene (or GO) sheets. Moreover, it is demonstrated that graphene interacts with the hydrophobic part of C12E4 LLC while GO mainly interacts with the hydrophilic part of C12E4 LLC because of the different properties of graphene and GO. Integration of graphene and GO into C12E4/PEG systems by a spontaneous phase separation method reveals the different interaction mechanisms of graphene and GO with C12E4 LLC. It can be concluded that the mechanical and electrical properties of the C12E4 LLC have been largely improved by the incorporation of graphene and GO, which opens the door for wide applications in nanotechnology, electrochemical and biochemical areas.
    Physical Chemistry Chemical Physics 08/2014; 16(38). DOI:10.1039/C4CP02634A · 4.20 Impact Factor
  • Fengfeng Gao, Hui Yan, Qiwei Wang, Shiling Yuan
    [Show abstract] [Hide abstract]
    ABSTRACT: In enhanced oil recovery (EOR), the micro-oil droplet heavily affected the stability of foam and prevented foam flooding. In this paper, the oil bridge-stretching mechanism of foam rupture was described through molecular dynamics with the aim of providing supplements to the experiments at the molecular level. Two important phenomena for foam rupture have been pointed out by the simulation. One is about the pseudoemulsion film, representing the stability of the oil-water-air three phase interface. The bound water connecting the headgroups of the surfactant through strong H-bonding interactions played a vital role in the stability of the pseudoemulsion film. These water molecules could hinder the disappearance of the water phase in the pseudoemulsion film. The additional energy barrier, which was influenced by the surfactant concentration, also played a vital role in preventing the destruction process. The other factor is about the oil bridge, which appeared after the destruction of the pseudoemulsion film. The external horizontal force stretched the bridge resulting in the destruction of the bridge. The process was decided by the properties of the oil molecules. In the simulation, the stretching force was divided into three stages including the initial increasing force, the middle equilibrium force and the final decreasing force. Especially the second equilibrium force, which stretched the middle of the oil bridge so that it became thin, was vital to the foam rupture. The concentration and properties of the oil molecules were the crucial factors for foam rupture. The simulated results offer important supplements to experiments.
    Physical Chemistry Chemical Physics 07/2014; 16(32). DOI:10.1039/c4cp02038c · 4.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The adsorption of polyelectrolyte surfactant mixture of sodium poly(acrylic acid) (NaPAA) and dodecyl trimethyl ammonium bromide (C(12)TAB) at the air/water interface was studied using molecular dynamics simulation. In our simulations, the transition from monolayer adsorption of a polymer surfactant complex to a multilayer structure was observed with increasing surfactant concentration at the interface. For the multilayer structure, the two polyelectrolyte chains were linked by two layers of surfactant molecules which adopted a tail-to-tail arrangement. The results indicated that the electrostatic interaction was the main driving force for the binding of surfactants to the polyelectrolyte, meanwhile the hydrophobic interaction between surfactant tails induced a layer-by-layer packing arrangement at high surfactant concentration. The dynamic properties of inorganic ions implied that the complex of polyelectrolyte and surfactant was an ion-exchange process. Our conclusions are in accordance with experimental results on polyelectrolytes and ionic surfactants.
    Colloids and Surfaces A Physicochemical and Engineering Aspects 07/2014; 454:104–112. DOI:10.1016/j.colsurfa.2014.04.009 · 2.35 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Carbon nanotubes (CNTs) were incorporated into a lyotropic liquid crystal (LLC) matrix at room temperature through spontaneous phase separation. The phase separation process occurred in n-dodecyl tetraethylene monoether (C12E4) solutions induced by the hydrophilic polymer, poly(ethylene glycol) (PEG). It was found that the molecular weight of PEG has a significant effect on the CNTs-C12E4 system, which not only influences the phase behavior of the system but also changes the properties of the CNTs-LLC composites. Polarized optical microscopy (POM) images, combined with small-angle X-ray scattering (SAXS) results, indicate that CNTs incorporate within the layers of the lamellar LLCs without destroying the structure of LLCs. Moreover, UV-vis absorption, Raman spectra and rheological measurements were performed to investigate the characteristic properties of the CNTs-LLC composites. This study not only gives a more comprehensive understanding of polymer-induced phase separation, but also expands the potential uses of CNTs-LLC composites in nanotechnology.
    Physical Chemistry Chemical Physics 06/2014; 16(28). DOI:10.1039/c4cp00622d · 4.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The adsorption of the anionic surfactant, sodium dodecylsulfate (SDS) in poly(ethylene oxide) (PEO) brush was studied by molecular dynamics simulations. Our simulations revealed that surfactant can adsorb in polymer brush as micellar aggregates and the polymer would reside at the hydrocarbon-water interface of SDS micelles. This association between surfactant and polymer was mainly driven by the hydrophobic interaction between the polymer and surfactant tails. In the simulation, with the increasing of surfactant concentration, a plateau value representing saturated adsorption was observed. The height of polymer brush was mainly affected by the adsorbed surfactant at low grafting density of polymer; however, it was primarily controlled by the grafting density at high grafting density. Our conclusions at the molecular level were in close agreement with experiment about the adsorption of surfactant in polymer brushes.
    Journal of Molecular Modeling 06/2014; 20(6):2267. DOI:10.1007/s00894-014-2267-8 · 1.87 Impact Factor
  • Peili Zhang, Zhen Xu, Qian Liu, Shiling Yuan
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, the detachment mechanism of alkane molecules from one hybrid hydrophobic and hydrophilic solid surface was studied by molecular dynamics simulation. First, some alkyl chains were linked through C-O bonds with silica surface to get one half-hydrophobic one, and the other half-hydrophilic area was still same as silica surface, thus one modified hybrid hydrophobic and hydrophilic silica surface was constructed. Second, some alkane molecules were adsorbed on the hybrid surface to get one whole hydrophobic oil layer, and the detachment mechanism of alkane molecules on the surface was discussed in aqueous solution using molecular dynamics. The simulated results showed that the key to the detachment of alkane molecules is the formation of water channel in oil layer between water phase and solid surface. In the detachment process, water molecules can penetrate oil layer to the silica surface through the strong H-bonding interaction among water molecules in water channel, and soon these molecules can form a gel layer along the silica surface by fast diffusion under the H-bonding interaction and electrostatic interaction between water molecules and silica surface. At last, the half-hydrophilic area on hybrid surface becomes hydrophilic again after the oil layer's detachment, and alkane molecules aggregate on the modified surface linked the alkyl chains. For the hybrid surface, some of alkane molecules insert into the interstice among the alkyl chains, and thus the oil drop cannot be dispatched thoroughly from the surface linked alkyl chains in aqueous solution. Our results showed that the detachment mechanism of oil from hybrid surface is different, compared with the whole pure hydrophilic surface.
    The Journal of Chemical Physics 04/2014; 140(16):164702. DOI:10.1063/1.4870930 · 3.12 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Template directed growth of functional organic molecules is a recently developed technique to generate organic micro/nano-structures on surfaces. Using templates of a metal patterned substrate, two different mechanisms were observed: area selective nucleation on predefined patterns with molecules nucleated on top of patterns and step-edge induced area selective growth on the substrate. Until now, much work has been done to investigate the microscopic mechanism of the former one. However, little attention was paid to the latter one. Here in this work, a series of kinetic lattice Monte Carlo simulations were conducted to get deeper insight into the microscopic mechanism of step-edge induced area selective growth. The time-resolved process of structure formation, the relationship between nucleation control efficiency and template size, and different growth regimes were studied. The results agree well with experimental speculation while selecting appropriate interactions.
    RSC Advances 01/2014; 4(48):25005. DOI:10.1039/c4ra01756k · 3.71 Impact Factor
  • Fengfeng Gao, Hui Yan, Shiling Yuan
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, the solubilisation process of pyrene molecule, as the fluorescence probe molecule, in cetyltrimethylammonium bromide (CTAB) surfactant micelle solution is studied by molecular dynamics (MD) method. When one pyrene molecule is in the micellar solution, it can be adsorbed into the micelle spontaneously and vertically. The probe molecule mainly locates in the interior cavity or the palisade layer of the micelle. When two pyrene molecules exist in the micellar solution, they transfer from the interior to the palisade layer. Although strong π–π interactions exist between the pyrene molecules, the pyrenes separate to each other in the palisade layer in two-third simulated time.
    Molecular Simulation 11/2013; 39(13). DOI:10.1080/08927022.2013.792929 · 1.12 Impact Factor
  • EnZe Li, ZhiPing Du, ShiLing Yuan
    [Show abstract] [Hide abstract]
    ABSTRACT: The microscopic behaviors of a water layer on different hydrophilic and hydrophobic surfaces of well ordered self-assembled monolayers (SAMs) are studied by molecular dynamics simulations. The SAMs consist of 18-carbon alkyl chains bound to a silicon(111) substrate, and the characteristic of its surface is tuned from hydrophobic to hydrophilic by using different terminal functional groups (-CH3, -COOH). In the simulation, the properties of water membranes adjacent to the surfaces of SAMs were reported by comparing pure water in mobility, structure, and orientational ordering of water molecules. The results suggest that the mobility of water molecules adjacent to hydrophilic surface becomes weaker and the molecules have a better ordering. The distribution of hydrogen bonds indicates that the number of water-water hydrogen bonds per water molecule tends to be lower. However, the mobility of water molecules and distribution of hydrogen bonds of a water membrane in hydrophobic system are nearly the same as those in pure water system. In addition, hydrogen bonds are mainly formed between the hydroxyl of the COOH group and water molecules in a hydrophilic system, which is helpful in understanding the structure of interfacial water.
    Science China-Chemistry 06/2013; 56(6). DOI:10.1007/s11426-013-4835-7 · 1.52 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Molecular dynamics simulations and quantum mechanics calculation were employed to study the deposition behavior of organic luminescent molecules rubrene onto bare dioxide silicon substrate and self-assembled monolayers (SAM) patterned substrate. A mixed system was constructed to investigate the edge-induced area-selective growth. Our simulation results suggest that the functionalized SAM decoration on the substrate surface exerts significant effect on the growth behavior and crystallinity of rubrene molecules. In the mixed system, the rubrene molecules diffused and preferetially deposited along the step-edge of SAM and formed a typical π-conjugated structure by standing up-right.
    Chemical Physics Letters 05/2013; 571:38–43. DOI:10.1016/j.cplett.2013.03.075 · 1.99 Impact Factor
  • Congyun Zhang, Hui Yan, Kai Lv, Shiling Yuan
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, we report a facile synthesis of mesoporous silica nanomaterials by utilizing cetyltrimethylammonium bromide (CTAB)/sodium dodecylbenzenesulfonate (SDBS) vesicle systems as templates. The porous nanostrucures with varied morphologies, including nanocapsules and nanospheres can be successfully fabricated by simply regulating the volume ratio (R) of ethanol to ethyl ether. In addition, we also investigated the influences of vesicular solution concentration on the nanomaterial morphologies with two different vesicle systems. A vesicle-templating mechanism was proposed to explain the formation of porous silica nanostructures.
    Colloids and Surfaces A Physicochemical and Engineering Aspects 05/2013; 424:59–65. DOI:10.1016/j.colsurfa.2013.02.014 · 2.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The Beiqian site, located in Jimo city, Qingdao, went through three archaeological excavations, and a large number of human and animal bones in the Dawenkou culture and the Zhou Dynasty period were unearthed. By carbon and nitrogen stable isotope analysis, the diet of ancestors is expected to be recovered, and the domesticated plants and animals will be discussed. The investigated results showed that the food structure of ancestors in both periods included food crops, mainly C4 foods, and meat, mainly marine shellfish and livestock. For domestic pigs, they mainly eat C3 plants, and were affected by the lifestyle of ancestors. This study also showed that the diet of ancestors is the shellfish rather than marine fish despite the Beiqian site is located near the shoreline. We can conclude that the diet of ancestors in Dawenkou culture period included millet crops (C4 plants), shellfish, marine food, and livestock, representing the lifestyle of farming, domestication, and fishing, supplemented by hunting. In the Zhou dynasty period the meat resource was enriched by domesticated animals and marine fisheries, and the living conditions were significantly improved.
    Science China Earth Science 03/2013; 57(3). DOI:10.1007/s11430-013-4637-y · 1.34 Impact Factor
  • Heng Zhang, Hua Wang, Guiying Xu, Shiling Yuan
    [Show abstract] [Hide abstract]
    ABSTRACT: Fmoc protected D-Ala-D-Ala dipeptides were known to self-assemble into supramolecular hydrogel with interesting properties. However their molecular mechanisms were not well understood. In this study, a series of coarse grained molecular dynamics simulation were conducted to investigate the formation of this hydrogel at different concentrations. The three dimensional network of hydrogel and the stacking of the Fmoc planes were observed intuitively from the snapshots of the trajectory. Importantly, by analyzing the RDF of Fmoc planes’ centriods and the distribution of neighboring Fmocs, we confirmed the π–π interaction as the mainly driving force for the gelation process.
    Colloids and Surfaces A Physicochemical and Engineering Aspects 01/2013; 417:217–223. DOI:10.1016/j.colsurfa.2012.10.066 · 2.35 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: At present, rubrene, which exhibits a high charge mobility, has become one of the most promising organic semiconductors because of its potential applications in organic thin-film transistors (OTFTs). The performance of organic molecule crystalline films is governed by both their molecular packing state phase and their molecular structures, which are greatly influenced by the growth process and inducing layer. In this paper, molecular dynamics (MD) simulations were performed to study the deposition behavior and crystallization of rubrene films. Four systems with different self-assembled monolayers (SAMs) were constructed to investigate the microscopic configuration of rubrene deposition, their interfacial reactions, and to further discuss how the template structures affect the crystallization of rubrene molecules. Our results suggest that the phase states of the inducing layer exhibit a significant effect on the rubrene growth. The theoretical results are consistent with the experimental findings and provide theoretical assistance on the further design of appropriate inducing layers for the crystallization of organic molecules.
    RSC Advances 01/2013; 1(35). DOI:10.1039/c3ra41085d · 3.71 Impact Factor
  • Hua Wang, Heng Zhang, Chengbu Liu, Shiling Yuan
    [Show abstract] [Hide abstract]
    ABSTRACT: Coarse-grained molecular dynamics simulations have been performed to study the self-assembly of polymer, polyacrylamide (PAM) and surfactant, sodium dodecylsulfate (SDS) in aqueous solution. Our simulations revealed that PAM curled into clusters in the absence of SDS, while it was stretched if SDS was added. For the SDS-PAM complexes, the aggregate formation process can be divided into three stages: firstly, PAM quickly absorbs some SDS monomers until the radius of gyration (Rg) of polymer reaches a minimum; then, PAM stretches and the Rg of PAM increases due to more and more adsorbed SDS; ultimately, the commonly accepted "necklace" structure is formed with PAM located at the interface of the hydrophobic and hydrophilic regions of the SDS micelle. The main driving force for the association was hydrophobic interactions between the polymer backbone and the surfactant hydrophobic tails. As the concentration of SDS increased, the Rg of PAM increased up to a maximum, indicating the polymer was saturated with surfactant.
    Journal of Colloid and Interface Science 07/2012; 386(1):205-11. DOI:10.1016/j.jcis.2012.07.026 · 3.55 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The Beiqian site located in Jimo city, Qingdao, a few kilometers from the modern coastline was excavated in 2007, 2009 and 2011. A large number of human bones from the early Dawenkou period were unearthed. Through C and N stable isotopic analysis, the food structure of the “Beiqian” ancestors was reconstructed and the influence of terrestrial and marine resources on their lifestyle was discussed. Based on the δ 13C and δ 15N stable isotopic values of human bone collagen, the analytical results obtained through a ternary mixed model reveal that the food sources of the Beiqian ancestors included about 44.1% marine species (probably shellfish and fish), 34.1% C4 plants (possibly millet), and 21.8% land animals. These results indicate that they lived mainly from fishing and farming, supplemented by hunting or poultry raising. Compared with other sites in the same period, the stable isotope results show that 5000–6000 years ago, the lifestyles of ancestors in the Yangtze River basin, Yellow River basin, Northern coastal area and inland area were very different. The ancestors from the Yangtze River basin focused on rice farming and fishing, whereas the ancestors in the Yellow River basin farmed millet and raised animals. Those in coastal areas relied mostly on farming and marine fishing.
    Chinese Science Bulletin 06/2012; 57(17). DOI:10.1007/s11434-012-5029-y · 1.37 Impact Factor
  • Kai Lv, Haitao Kang, Heng Zhang, Shiling Yuan
    [Show abstract] [Hide abstract]
    ABSTRACT: Molecular simulation studies were performed to explore the properties of functionalized Mg–Al layered double hydroxides (LDHs). Using molecular dynamics (MD) simulations, the intercalation of photoactive dyes (methyl orange, MO) into a Mg:Al 2:1 LDH system were studied, for which some limited experimental data have been reported (J. Colloid Interface Sci. 2008, 318, 337). The interlayer structure, hydrogen bonding, and consequent swelling of LDH compounds containing MO molecules were shown on the molecular level. Quantum mechanical density functional theory was also employed in order to get the geometry optimization and atomic charges. The concentration profiles, mean square displacement (MSD), and self-diffusion coefficient were calculated using the trajectory files on the basis of MD simulations, and the results indicated that the MO molecules were much more stable when intercalated into the LDH layers. The orientation of the intercalated MO molecules was measured at the interface of the LDH layers. The tail vectors of the MO molecule were tilted with an average angle from 70° to 76°, and most of the angular distribution is about 74.15°, which had a good agreement with the experimental data 74.1°.
    Colloids and Surfaces A Physicochemical and Engineering Aspects 05/2012; 402:108–116. DOI:10.1016/j.colsurfa.2012.03.032 · 2.35 Impact Factor
  • Qian Liu, Shiling Yuan, Hui Yan, Xian Zhao
    [Show abstract] [Hide abstract]
    ABSTRACT: The mechanism of oil detachment from solid surfaces in aqueous surfactant solutions is studied by molecular dynamics simulations. At the initial simulation, the hydrophilic silica surface changes into a hydrophobic one due to the adsorption of the alkane molecules. Two-dimensional ordered arrangement of alkane molecules on the first layer is the key to the oil detachment from the silica surface. Upon addition of cetyltrimethylammonium bromide (CTAB) solution, the alkane molecules on the solid surface can be detached from a hydrophilic silica surface. Ultimately, the silica surface becomes hydrophilic, and the oil molecules are solubilized in the surfactant micelles. During the process of oil detachment, it is demonstrated that the formation of a water channel in the oil phase between the surfactant solution and the silica surface is vital for the oil detachment. Meanwhile, water molecules can penetrate the oil-water interface by diffusion and form the gel layer at the water-silica interface under the hydrogen-bonding and electrostatic interaction, in the close vicinity of the contact line. Both of these will accelerate the removal of the oil molecules from the silica surface under the surfactant solution. According to the energy and configurations with time evolution, one three-stage model of oil detachment from the silica surface is developed at the molecular level. The simulation results agree with the experimental phenomenon.
    The Journal of Physical Chemistry B 03/2012; 116(9):2867-75. DOI:10.1021/jp2118482 · 3.38 Impact Factor