Heterogeneous systems containing ionic liquids (ILs) with gases and solvents extend the acpplications of ILs in absorption, extraction and heterogeneous catalysis. In recent years, the surface/interfacial properties and surface/interfacial structures of ionic liquids have been widely studied, because they are important due to their remarkable effects on heterogeneous reactions and separation efficiency. In this article, the surface/interfacial tension,as well as the surface/interfacial structures of ILs and their mixtures with water and organic solvents are summarized. The research methods, objectives and results are introduced. The relationship between surface/interfacial tension and surface/interfacial structures is elucidated. Finally, the exiting problems and development prospects of the studies on surface/interfacial properties and surface/interfacial structures of ILs are discussed.

Contents
1 Introduction
2 Surface tension of ionic liquids and their mixtures
2.1 Surface tension of ionic liquids
2.2 Surface tension of ionic liquid mixtures
3 Liquid/liquid interfacial tension of ionic liquids
4 Surface/interfacial structures of ionic liquids
4.1 Direct recoil spectroscopy
4.2 Neutron and X-ray reflectivity
4.3 Ultra-high vacuum systems
4.4 Non-linear spectroscopy
4.5 Molecular dynamic simulation
5 Conclusion and outlook

This review summarizes the research progress on the use of ionic liquids(ILs) as catalysts for the cycloaddition of CO₂ with epoxides to prepare cyclic carbonates. The reported ILs for this reaction include imidazole salt, quaternary ammonium salt, quaternary phosphonium salt, and so on. Systematical comparison has been made between the conventional ILs and functional ILs in the terms of their catalytic performances and reaction mechanisms. Generally, the conventional ILs show poor catalytic efficiency towards this coupling reaction, thus co-catalysts are usually needed to improve their catalytic activity. Compared with conventional ILs, functionalized ILs show much better catalytic performance due to the synergistic effect between hydroxyl or carboxylic acid group and Lewis base such as halide anions. As to the supported ILs catalysts, inorganic material SiO₂ is the most common support for immobilizing or supporting ILs catalysts.In the recent years, mesoporous materials such as SBA-15 and MCM-41 whose surfaces are of hydroxyl groups can also be used to immobilize ILs. Besides inorganic materials, polymers are another type of important supports, and the polymers-supported ILs are more stable than ILs on inorganic supports. Moreover, there is synergistic effect between the active components and supports of the immobilized functional ILs, resulting in better catalytic performance. It is emphasized that supported ILs catalysts have good potential applications in industry since they show good catalytic activity, selectivity and recyclability. What's more, ILs can also be used as catalysts for the preparation of chiral cyclic carbonates with good yield and enantioselectivity.

Contents
1 Introduction
2 Homogeneous ionic liquid catalysts
2.1 Traditional ionic liquid catalysts
2.2 Functional ionic liquid catalysts
3 Heterogeneous ionic liquid catalysts
3.1 Ionic liquid catalysts immobilized on inorganic materials
3.2 Ionic liquid catalysts immobilized on polymers
4 Ionic liquids used in preparation of chiral cyclic carbonates
5 Conclusions and outlook

The ordered molecular aggregates based on ionic liquids (ILs) have attracted increasing interest due to their unique physicochemical properties and potential applications in various areas. Combining with our work, the recent progress in the micelle formation based on ILs is summarized. The aggregation of traditional surfactants in ILs, self-organization of surface-active ILs in aqueous solutions, as well as the effect of ILs on micelles formed by traditional surfactants are reviewed emphatically. Based on these studies, the mechanisms and regularities of micellization for some systems are proposed, and the trend for future research is prospected.

Contents
1 Introduction
2 ILs as solvents
2.1 Micelle formation of cationic surfactants in ILs
2.2 Micelle formation of anionic surfactants in ILs
2.3 Micelle formation of nonionic surfactants in ILs
2.4 Micelle formation of amphiphilic copolymers in ILs
3 ILs as surface-active agents
3.1 Micelle formation of common ILs in aqueous solution
3.2 Micelle formation of common ILs in non-aqueous solution
3.3 Micelle formation of functional ILs in aqueous solution
4 Effect of ILs on micelles formed by traditional surfactants
4.1 ILs as co-surfactants
4.2 ILs as salts
5 Prospects

In the recent decades, superhydrophobic surfaces have attracted increasing attention in both fundamental research and practical applications due to their water-repellent and self-cleaning properties, inspired from plant leaves in nature, such as lotus leaf with special wettability and fine micro-structures on their surfaces. In this feature article, we review two classical wettability models and mainly focus on the development of the potential applications of biomimetic superhydrophobic surfaces in the last three years, including super-oil-repellent surfaces, micro-fluidics, wetting conversion, smart surfaces, and anti-icing. Finally, the promising applications of biomimetic superhydrophobic surfaces in the future are proposed.

Contents
1 Introduction
2 Basic principles of solid surface wettability
3 Applications of bio-inspired superhydrophobic surfaces
3.1 Super-oil-repellent surfaces
3.2 Superhydrophobic surface with wetting conversion
3.3 Solid wettability response to external conditions
3.4 Microfluidics for superhydrophobic surfaces
3.5 Anti-icing for superhydrophobic surfaces
3.6 Other applications
4. Conclusions and outlook

The Belousov-Zhabotinsky(BZ) reaction catalyzed by tris(2,2'-bipyridine)ruthenium(Ⅱ), one of the ideal chemical reaction system for studying nonlinear spatiotemporal dynamics, has unique photosensitive properties and can display rich spatiotemporal dynamical behaviors. Achievements of the photosensitive BZ reaction could help us to understand the complex dynamic phenomenon in physical, chemical and living systems. In this paper, the photo-effect on homogenous complex dynamics and reaction-diffusion chemical waves in ruthenium-catalyzed BZ reaction under different experiment conditions, as well as the complex dynamics in coupling system of the ruthenium-catalyzed BZ reaction with soft matter is reviewed. The photosensitive mechanisms and models are summarized. Finally, the existing questions and future directions of the research of photo-controlled BZ reaction systems are discussed.

Contents
1 Introduction
2 Complex spatiotemporal dynamic behavior of tris(2,2'-bipyridine)ruthenium(Ⅱ)-catalyzed BZ reaction
2.1 Homogenous oscillating reactions
2.2 Chemical waves in spatial reaction-diffusion systems
2.3 Ruthenium-catalyzed BZ reaction coupling with soft matter
3 Mechanism of photosensitive ruthenium-catalyzed BZ reaction
3.1 Mechanism of photoinhibition
3.2 Mechanism of photoinduction
4 Models
4.1 Models of photosensitive BZ reaction
4.2 gLSM model of photosensitive BZ reaction in responsive gel
5 Conclusions and outlook

Dye-sensitized solar cells (DSC) are regarded as a potential low-cost alternative to conventional solar cells and have attracted considerable interest during the past decades. The working mechanism of DSC is not yet fully been understood and needs further investigation. Electrochemical impedance spectroscopy (EIS) is a powerful technique to identify and study the working mechanism in DSC. Through the EIS measurements, some parameters, such as electron transfer resistance, electron transport resistance, capacitance, ion diffusion resistance, electron diffusion constant and electron lifetime, etc. can be obtained. After further processing of these data, the charge transport kinetics, the electron transfer kinetics, the electron collection kinetics, the semiconductor energy level changes and the density of states distribution can be analyzed. This paper summarizes the basic theory and experimental methods of EIS application in DSC. The latest research progress about the charge transport process, the electron transfer process, the impedance of DSC information extraction and the dynamic process analysis are reviewed. Furthermore, the application of EIS in various research fields of DSC, such as photoanode, electrolyte system, counter electrode, stability test, new structure design are introduced. Especially, the impedance characteristics of the various components of DSC are summed up and the latest progress in the study of the work mechanism in DSC are systematically summarized. The current problems existed in the research of EIS application for DSC are discussed and the future development is prospected.

Contents
1 Introduction
2 Basic theory of EIS application in DSC
2.1 Light and dark impedance characteristic research
2.2 Study on frequency response of DSC internal processes
2.3 Study on the mathematical model of EIS
3 Experimental methods of EIS application in DSC
3.1 The two electrodes and the three electrodes measuring system
3.2 The difference and connection between optical/electrical impedance in the frequency domain
4 Analysis of DSC impedance information
4.1 Study on the construction of DSC equivalent circuit
4.2 The impedance of the DSC information extraction and dynamic process analysis
5 The impedance characteristics of DSC
5.1 The impedance characteristics of optical anode
5.2 The impedance characteristics of the electrolyte system
5.3 The impedance characteristics of the counter electrode
5.4 The impedance characteristics of the dye/co-adsorbent
5.5 The impedance characteristics of the conductive substrate
5.6 EIS application in the stability
5.7 EIS application in the new structure cell
6 Summary and outlook

Biological apatite is the main inorganic mineral component of animal and human bone and tooth enamel, moreover apatite mineral composition and structure affect on the bone and tooth enamel mechanical strength and physiological behavior. The structure of hydroxyapatite (HAP) has proved more difficult to resolve, two different hydroxyl arrangements may occur in HAP resulting in hexagonal and monoclinic structures. Extensive isomorphic substitutions may greatly affect the properties of this mineral. In the paper, computational methods are well placed to calculate at the atomic level the geometry and relative energies of the various possible hydroxy groups in apatite, and they have been employed to study the uptake and distribution of small molecule or biomacromolecule in the hydroxyapatite. Application of computer simulation at the atomic level to investigate apatites, especially HAP, is anticipated to provide a deeper understanding of crystal chemistry and interaction with biomacromolecules. These results offer a more comprehensive investigation of bio-apatite and perspective applications.

Contents
1 Introduction
2 Applications of computer simulation to the apatite crystal
3 Applications of computer simulation to the apatite substitution
4 The interaction of apaptite and other molecules or ions
4.1 The interaction of apaptite and water molecules
4.2 The interaction of apaptite and haloid ions
4.3 The interaction of apaptite and citric acid molecules
4.4 The interaction of apaptite and biologic molecules
5 Conclusions and Outlook

As a new class of porous solids, metal-organic frameworks (MOFs) have attracted a great deal of interests of chemists in the world due to their unique properties, such as the high specific surface area, tailoring structure properties and 100% utilization of exposed metal ions. The chemical and structural versatility of such materials makes them potentially candidates for applications in catalysis. In this review, we focus our attention on olefins oxidation using MOF as catalysts. Three classes of MOF catalysts are active site at the inorganic nodes on the MOF, active site at the organic or pseudo-organic linkers, and MOF-supported active specie. The applications of the three classes of MOF catalysts on the olefins oxidation are discussed in detail.

Contents
1 Introduction
2 Catalysis by metal nodes on the MOF
2.1 Catalysis by Fe-MOF
2.2 Catalysis by Cu-MOF
2.3 Catalysis by Ni-MOF
2.4 Catalysis by Ln-MOF
2.5 Catalysis by Co-MOF
2.6 Catalysis by V-MOF
3 Catalysis by homogeneous catalysts incorporated as MOF struts at the organic or pseudo-organic linkers
3.1 Metalloporphyrins
3.2 Salen complexes
4 Catalysis by MOF-supported metals or clusters
5 Conclusions and Outlook

More and more rigorous environmental regulations limiting the emissions of sulfur dioxide and the continuing decline in the quality of petroleum feedstocks have given rise to the need for investigation and development of high-performance hydrodesulfurization (HDS) catalysts. This paper provides a review of recent progress in the characteristics, active phase, synthesis, modification and HDS catalytic performance of Ni₂P catalyst. There are two types of initial active sites in Ni₂P. The Ni(1) initial active sites have a tetrahedral geometry, and which are involved in the direct desulfurization pathway in HDS. The Ni(2) initial active sites have a square pyramidal geometry, and which are responsible for the high catalytic activity in the hydrogenation pathway in HDS. A surface nickel phosphosulfide phase may be formed under HDS reaction, and which is considered as the real active phase. Ni₂P is mainly prepared by temperature-programmed reduction and liquid phase synthesis. The support, promoter and complex agent have important effect on the formation of Ni₂P active phase, as well as the catalytic activity. Compared with commercial sulfide catalyst, the Ni₂P catalyst shows higher HDS activity for thiophene, dibenzothiophene and 4, 6-dimethyldibenzothiophene.

Contents
1 Introduction
2 Crystal characteristics of Ni₂P
3 Active phase of Ni₂P in HDS
4 Synthesis of Ni₂P catalysts
4.1 Temperature programmed reduction
4.2 Liquid phase synthesis
4.3 Other synthesis
5 Modification of Ni₂P
6 HDS catalytic performance of Ni₂P catalyst
7 Summary and perspective

The research of coordination polymers remain an extremely active field of material chemistry, coordination chemistry and crystal engineering in recent years due to their various network topologies and their potential applications in many aspects such as guest exchange/separation, gas storage, chiral resolution, selective catalysis, molecular recognition, fluorescence and magnetism. This paper summarizes the recent advancement on the structure of coordination polymer containing triazolate-carboxylate mixed ligands, which focuses chiefly on the role of carboxylate ligand in the crystal structure. The future research and development of coordination polymer constructed from triazole and carboxylate are also prospcted.

Contents
1 Introduction
2 The M/trz layer pillared by carboxylate ligand to construct the 3D structure
2.1 The pillared-layer structure in the M/trz/aromatic carboxylate system
2.2 The pillared-layer structure in the M/trz/aliphatic carboxylate system
3 The network built by carboxylate ligand and M/trz through coordinative covalent bonding
3.1 The typical topological structure constructed by carboxylate ligand and M/trz
3.2 The novel topological structure constructed by carboxylate ligand and M/trz
4 The network built by carboxylate ligand and M/trz through weak intermolecular interactions
5 The properties of coordination polymers constructed from triazolate and carboxylate mixed ligands
6 Conclusion and outlook

The unique physicochemical properties of gold nanorods make them very useful in the fields of catalytic reactions, ultrasensitive detection, biological diagnostics, and so on. These properties of the gold nanorods can be tailored by either the morphology controlling or the surface coating. The preparation, characterization and optical properties of inorganics-coated gold nanorods that are typically core-shell nanorods are summarized in this paper. The emphasis is focused on the Au@Ag core-shell nanorods that have been widely explored in terms of optical properties and potential applications. Finally, the prospective of the gold-based core-shell nanorods is given.

Contents
1 Introduction
2 Au@Metal core/shell nanocrystals
2.1 Au@Ag core/shell nanorods
2.2 Au@Au core/shell nanorods
2.3 Au@Pd core/shell nanorods
2.4 Au@Pt core/shell nanorods
2.5 Au@PdPt core/shell nanorods
2.6 Au@Ni core/shell nanorods
3 Au@Oxide core/shell nanocrystals
3.1 Au@SiO₂ core/shell nanorods
3.2 Au@Other inorganic oxide core/shell nanorods
4 Conclusion and prospects

Computer-aided rational protein design was demonstrated to be effective in addressing important issues in chemistry and biology. With computer simulation, a structural and functional nitric oxide reductase (NOR) was successfully designed using myoglobin (Mb) as a protein model, which was accomplished at the time with no three dimensional structure available for NOR itself. More importantly, the designed NOR protein model, Fe_BMb, was confirmed by an X-ray structure of native NOR one year later. The progress and rationalities of design of Fe_BMb, I107E Fe_BMb, as well as Fe_BMb(-His), were reviewed herein. The use of molecular simulation to obtain atomic structural information on Mb in a non-native state with bis-Histidine coordination was also highlighted, as the information was otherwise difficult to obtain experimentally. The general application of computer-aided rational protein design will provide deep insight into biological systems.

Contents
1 Introduction
2 Myoglobin: an ideal scaffold for protein molecular design
3 Nitric oxide reductase: both a chance and a challenge for protein molecular design
4 Exploring unknown areas: ongoing of protein molecular design
5 Conclusion and outlook

Supramolecular smart organogels based on cholesterol, which has special multi-rings and multi-chiral carbon structures, have been paid much attention during recent years. This kind of gels can exhibit a dramatic change in their properties in response to temperature, as well as other environmental stimulus, such as light, pH and ultrasound. Since cholesterol molecules are the universal class of biological molecules in life, the smart cholesterol-gel materials have potential advantages in life phenomena simulation, drug delivery, etc. In the paper, the structures and properties of the gel system are introduced according to the types of the gel system at first, including photo-responsive, redox-responsive, pH-responsive, ultrasound-responsive, metal ion-responsive and thixotropy-responsive. Then the modification method of the gelator is described. Finally, based on the current developments of the system, the directions and the prospects are pointed out.

Contents
1 Introduction
2 Types and the structures and properties of cholesterol-base intelligent organogels
2.1 Photo-responsive
2.2 Redox-responsive
2.3 PH-responsive
2.4 Ultrasound-responsive
2.5 Metal ion-responsive
2.6 Thixotropy-responsive
3 Synthesis of cholesterol gelators
3.1 Amide bond
3.2 Ester bond
4 Prospects

Biomass is the only renewable resources on the earth that can derive liquid fuel and fine chemicals to replace the petroleum-based chemicals. In recent years, the development of bioenergy concerning the synthesis of levulinate esters from biomass via chemical/catalytic process has attracted more and more concerns, and extensive research is being carried out worldwide. Levulinate esters, like methyl levulinate, ethyl levulinate, and butyl levulinate, are a kind of important intermediates and energy chemicals having high reactivity and widespread application in many fields. Up to now, there are four developed potential pathways for the synthesis of levulinate esters from biomass conversion, including the direct acid-catalyzed alcoholysis of biomass, the esterification of levulinic acid that from hydrolysis of biomass, the alcoholysis of 5-(chloromethyl)furfural derived from biomass, and the alcoholysis of furfuryl alcohol that from hydrogenation of furfural. In this review, the chemical reaction process and recent research progress for the above four pathways are introduced. The characteristic and development tendency of these pathways are reviewed from the production process, catalytic system and economic feasibility. Based on the present research situation, the technology and engineering barriers for the conversion of biomass to levulinate esters in commercial scales are analyzed and discussed, and the future research trend in the field is prospected.

Contents
1 Introduction
2 Direct acid-catalyzed alcoholysis of biomass for levulinate esters production
2.1 Alcoholysis process of cellulosic biomass
2.2 Catalytic systems
2.3 Kinetics of biomass alcoholysis
2.4 Side reaction of inter-molecular dehydration of alcohol
3 Levulinate ester synthesis from biomass via levulinic acid
3.1 Synthesis route
3.2 Esterification of levulinic acid
4 Levulinate ester synthesis from biomass via 5-(chloromethyl)furfural
4.1 Synthesis route
4.2 Preparation of 5-(chloromethyl)furfural
4.3 Alcoholysis of 5-(chloromethyl)furfural
5 Levulinate ester synthesis from biomass via furfural and then furfuryl alcohol
5.1 Synthesis route
5.2 Alcoholysis of furfuryl alcohol
6 Conclusion and outlook

Organosilicon compounds have attracted considerable interest as electrolytes for lithium-ion batteries because they are nontoxic, nonflammable, as well as have lower glass transition temperatures, lower vapor pressure and higher flash point than commercial alkyl carbonates. These compounds can improve the electrochemical performances and safety of lithium-ion batteries when used as electrolyte solvents or additives in the electrolytes. In this paper, the recent advances of organosilicon compounds both as electrolyte solvents and additives are reviewed. Organosilicon electrolytes containing ethylene oxide(EO) substituents with or without carbon spacer between silicon atom and EO unit are specially remarked as safe electrolytes. Organosilicon compounds as functional additives are also introduced in terms of the capabilities of passive film formation, flame-retardant, and acid/water scavenger.

Contents
1 Introduction
2 Organosilicon electrolyte solvents for lithium-ion batteries
2.1 Alkylsiloxane(Si—O) based electrolyte solvents
2.2 Alkylsilane(Si—C) based electrolyte solvents
2.3 Liquid oligomeric siloxane(—Si—O—Si—) based electrolyte solvents
3 Organosilicon electrolyte additives for lithium-ion batteries
3.1 Film-forming additives
3.2 Flame retardant additives
3.3 Acid and water scavenge additives
3.4 Low temperature and high output additives
3.4.1 Cyclic carbonate modified organosilicon compounds
3.4.2 Silane compounds containing EO group
4 Conclusions and outlook

As one kind of the xanthenes, rhodamine dyes have excellent photophysical properties, such as long absorption and emission wavelengths elongated to visible region, high fluorescence quantum yield, and large absorption coefficient, etc. Therefore, rhodamine-based dyes have become one of the perfect chromophores for making fluorescent probes. In the paper, the recent progress in the studies on rhodamine-based fluorescent probes for metal cations are reviewed. Especially systematically discuss about the rhodamine-based fluorescent probes for copper ion, mercury ion and iron ion that are based on the mechanism of screw amide ring “off-on”, the mechanism of fluorescence resonance energy transfer and the mechanism of photoinduced electron transfer. The structure, detecting level and applications are discussed in detail. Moreover, the problems and developing trends with this kind of fluorescent probe have also been discussed.

Contents
1 Introduction
2 Selective probes for copper ion
3 Selective probes for mercury ion
3.1 Probe with sulfur atoms coordination
3.2 Probe without sulfur atoms coordination
3.3 Probe with mercury ion induced chemical reactions
4 Selective probes for iron ion
5 Selective probes for other metal ions
6 Conclusions and outlook

Trace elements play a vital role in life activities. The abnormal level of trace elements, alteration of their speciations, changes of expression, location, structure and function of specific metalloenzyme and metalloprotein are often related to some pathological states, even are the key factors for pathogenesis. Thus the high-throughput analysis of the location, concentration, chemical form of metals in organism is an important subject in life science. In this review, various approaches to extraction and separation of metal-containing proteins are introduced and compared with emphasis on the application of different electrophoresis techniques to separation of metalloproteins. The influence of all these analysis processes to metals associated with proteins is also evaluated, along with the possible approaches to improvement of these processes.

Contents
1 Introduction
2 Methods for protein extraction
3 Methods for protein separation and metal element analysis
3.1 High-performance liquid chromatography(HPLC)
3.2 Capillary electrophoresis(CE)
3.3 Electrophoresis
4 Conclusion and prospects

Molecularly imprinted polymer(MIP), a material which owns artificially-created binding sites coupled with several distinct advantages such as high chemical, mechanical and thermal stability, robust, easy preparation, low cost and reusable. MIP as mimic in pseudo-immunoassays have attracted considerable attention over the last few years. The advances in molecularly imprinted sorbent immunoassays(MIAs) are reviewed from radioligand immunoassays to non-radioligand immunoassays, and emphasize on the promotion which homogeneous immunoassay systems and new synthesis methods bring. It is shown that the perceived disadvantages of MIP can be ignored in MIAs. The existing problems and prospects of MIAs are also described.

Contents
1 Introduction
2 Molecularly imprinted sorbent immunoassays(MIAs)
2.1 Heterogeneous MIAs
2.2 Homogeneous MIAs
3 Application of new synthesis methods in MIAs
3.1 Suspension polymerization
3.2 Precipitation polymerization
3.3 Reversible addition-fragmentation chain transfer(RAFF) polymerization
3.4 Photolithography polymerization
4 Conclusions and outlook

Supported phospholipid bilayers(SPBs) are popular as model systems for cell membranes and are ideal material for fixing biological active substances. In addition, SPBs can not only maintain the biological activity of molecules, but also inhibit other non-specific adsorption of biological molecules. SPBs are promising for future applications in the transmembrane protein, biomimetics, treating water, biomedicine and biosensors. The characterization and preparation methods of SPBs are reviewed, which include Langmuir-Blodgett technique, lipid vesicles fusion approach, and the combination of Langmuir-Blodgett technique and vesicles fusion approach. It is described in detail that the formation mechanisms of SPBs triggered by vesicles fusion approach. The factors of the formation of SPBs are also reviewed in this paper, including the concentration of vesicles, buffer solution, temperature, charge of vesicles and the solid surface. In the end, the applications of SPBs and the latest trends in the study of SPBs are predicted.

Contents
1 Introduction
2 Characterization methods of SPBs
3 Preparation methods of SPBs
3.1 Langmuir-Blodgett technique
3.2 Vesicle fusion
3.3 Combination of Langmuir-Blodgett monolayer transfer and vesicle fusion
4 Influence factor
4.1 Influencing of surface charge about vesicle and support
4.2 Influencing of buffer solution
4.3 Influencing of temperature
4.4 Influencing of vesicle concentration
4.5 Influencing of surface property
4.6 Influencing of osmotic pressure
5 Application
5.1 Biomembrane model
5.2 Sensors
5.3 Biomedicine
5.4 Treating water
6 Prospects

Nanofiltration(NF) membrane has been developed from the late 1980s and widely applied in the separation of liquid mixtures. Several models for NF process have been proposed, such as the pore model based on the sieving effect, the charge models based on the electrostatic effect, and the electrostatic steric-hindrance model and the Donnan steric pore model based on the both effects, which play an important role in understanding the separation mechanism and promoting the application of NF. However, the performances of these NF membranes with features of “loose RO membranes” cannot be predicted by commercial RO simulation software, which is a severe restriction on straightforward implementation of large-scale NF applications. In regard to these problems, a model was proposed for the separation performance of mixed salts solution across NF membranes to promote the application of NF during the water treatment in the light of the competitive effect among co-ions and regulation effect among counter-ions. Both two effects can be determined by some specific experiments. Recently, based on the in-depth experimental studies on rejection performance and the attendant electrokinetic properties, some researchers have found that the performance of NF membranes cannot be predicted completely by merely considering the sieving and electrostatic effect, but some drawbacks still exist in the analysis of electrokinetic properties. The further studies have contributed to a deeper understanding on the particular effect caused by the nano-scale pore size and charge features caused by the complicated interaction in solution. Moreover, the dielectric effect in the transport process of ions through NF membranes has been addressed and quantitatively analyzed.

Contents
1 Introduction
2 Models of nanofiltration
2.1 Non-equilibrium thermodynamic model
2.2 Charge models
2.3 Pore model
2.4 The electrostatic and steric-hindrance model
2.5 Models relevant to dielectric exclusion effect
3 Simulation of rejection for mixed salts
4 Transmembrane electrical potential and recognition on separation mechanism
5 Conclusion and Outlook