Membrane technology could realize molecular-level separation with low cost and high efficiency， which has become a generic technology for solving the big challenges that the mankind faces such as resources and environmental problems. A growing number of countries have paid significant attention to development of membrane technology. In recent years， with the great support from government and continuous R & D efforts， China has made a considerable progress in membrane science and technology. This paper will give a historical review of membrane technology in China. Recent 10-year innovations in fields of water treatment membranes， pervaporation membranes， gas separation membranes， ion exchange membranes， inorganic membranes， membrane reactors， novel membranes will be shown based on the fundamental study and industrial implementation of membrane design， preparation and application. And futuredevelopment directions and goals of the membrane science and technology in China are prospected.
As to the status of water shortage and severe water pollution， developing an effective strategy to ensure the water security is one of the urgent issues. Membrane-based water treatment is highly focused and studied to ensure the water security due to its high efficiency and easy-to-operate. In this paper， the connotation and status of water security in China were presented， and a detailed review was drawn on the application of membrane technologies to develop water resources and reduce wastewater emission. Finally，suggestions were listed for the development of membrane-based water treatment in water security.
Reverse osmosis (RO) and nanofiltration (NF) separation are effective technologies， and have been used in many fields such as the desalination of seawater， ultrapure water production， wastewater treatment as well as water softening. Since the inherent chemistry of the monomers employed in the interfacial polymerization is believed to play a major role in determining the properties of the resulting TFC membranes， a deeper insight into the relationship between the properties of the membrane chemistry and the chemistry of functional monomers is necessary. In the present report， series of novel RO as well as NF membranes based on new type of polyacyl chloride monomers have been prepared. We systematically investigated the intrinsic relationship between the physicochemical properties， transport performance as well as anti-fouling properties of the resultant membranes and the chemistry the polycayl chloride monomers. The result reveal that， as the functionality of the acid chloride monomer increased， the resulting membrane skin layer became more negatively charged， thinner and smoother， and better antifouling ability. All the four membranes exhibited close salt rejection rates. Additionally， a novel positively charged thin film composite NF membrane was prepared utilizing the highly functional 2，2’，4，4’，6，’6-biphenyl hexaacyl chloride (BHAC) monomer. This NF membrane exhibits high efficiencies for many NF applications including rejection of divalent cations， removal of basic dyes and selective separation of mixed cations.
Nowadays membrane technology has been widely employed in the treatment of industrial wastewater and municipal sewage. In the last decade， plenty of work focused on the preparation and industrialization of advanced polyvinylidene fluoride (PVDF) membranes with excellent performance has been carried out by the Chemical Engineering Department in Tsinghua University， which follows the line of preparation formula design， advanced production and membrane module development. This paper reviewed the history information about these researches. Firstly， PVDF membranes with good performance were prepared via thermally induced phase separation (TIPS) method based on thermodynamic and dynamic researches on the membrane formation process. Secondly， advanced production of PVDF hollow-fiber membrane was achieved by an effective combination of material processing and unit operation. Finally， different modules were designed and fabricated according to the characteristic of PVDF membrane prepared via TIPS method and different application situations. The results show that the PVDF membranes prepared via TIPS method break through the traditional phase separation limitation and exceed performance expectation； as a result TIPS method can be the top option for wastewater treatment.
The non-solvent phase separation (NIPS) is a highly efficient membrane preparation method which was invented in 1960s. Membranes prepared by NIPS method always possess asymmetric structure with a denser top layer and looser support layer which gives the membranes excellent selectivity and permeability. What’s more， the structure of the membranes could be easily controlled By NIPS method. So it has been widely used in research and commercial manufacture of membranes. Poly (vinylidene fluoride) (PVDF) has excellent chemical and mechanical properties and has been widely used. PVDF ultrafiltration (UF) membranes could be easily prepared by NIPS method. Owing to the excellent separation properties， PVDF UF membranes have been widely used in wastewater treatment， pure water production， pretreatment of seawater desalination， etc. The preparation process， the control method of the micro-pores and the application of PVDF UF membranes have gained most attentions and became worldwide research hot area. In this paper， we made a brief introduction about the research progress on the phase separation theory of PVDF UF membranes prepared by NIPS， membrane structure control method and its application， etc.
Membrane separation technology is contemporarily a high and new technology in chemical engineering. It has been consequently developed rapidly in recent 30 years due to the availability of solving many serious problems， such as energy， resources and environment. Membrane separation technology of pervaporation as a novel separation technology is typically energy-saving and cleaner-production technology. Compared to the conventional azeotropicdistillation and extractive distillation applied to azeotropic systems， pervaporation process could lead to an energy saving of 1/3～1/2 and decrease operating costs even no less than 50 %. The industrial applications of the pervaporation dehydration over the world are introduced， and research progresses and industrial feasibilities of several pervaporation membranes are shown in this paper， which cover gasoline desulfurization membranes， methanol and ethanolpermselective membranes， dimerthyl carbonate/methanol and arene/alkane separation membranes.
A seeding method by rubbing-dipcoating and induction with ball-milled seeds was developed to synthesize NaA zeolite membrane. The synthesis approach could improve the rate of qualified membranes and reduce the synthesis time efficiently，which is suitable for large-scale production of zeolite membranes. Mass transfer mechanism of organic solvent and water in a zeolite membrane was investigated with molecular simulation method. The stability of NaA zeolite membranes in hydrothermal，acid-base and salty environments was systematically studied. A pretreatment method was then proposed and industrial pervaporation plants were built up，which have been operated steadily for long term.
During recent years， membrane integration process has attracted wide attentions. The study on combination of the traditional separation technology and membrane process is conducive to the advantages such as high efficiency， easy online， etc. It is significant for the large-scale application of membrane integration process with low cost. Membrane adsorption and membrane absorption processes， which combined the advantages of membranes with adsorption， gained wide?applications for numerous occasions such as purification and separation. The research advances and development tendency of membrane adsorption and absorption will be introduced in this article， which can provide some suggestions for the researchers of related fields.
Several processes by integrating with membrane systems such as stripping-membrane-distillation， multiple stage membrane concentration， pervaporation- distillation， etc. were designed and developed to treat chemical wastewater containing valuable components（e.g.， polyol， polybasic acid， ester， inorganic salt）. The combination of the integrated processes with the chemical production processes can effectively reduce COD in the treated wastewater and realize the recovery of the valuable components in chemical wastewater， and consequently decrease the cost of wastewater treatment. Therefore， application of these processes could be helpful for the sustainable development of chemical industry.
Due to the special ion transfer characteristic in ion exchange membranes，the electro-membrane processes based on ion exchange membranes can achieve the separation and classification of the ions，which have found more and more important applications in clean production，energy-saving and emission reducing，environmental protection，and energy conversion. The ion exchange membranes processes meet with the demands of energy-saving，reuse of raw material，and pollution prevention in modern industries，and have become one of the key components for sustainable development in our economy. However，the preparation and applications of homogenous in exchange membranes are still at infant stage of development in China due to technological embargoes and price monopoly by the Japan leaded developed country. As a consequence，it is of great significance for the development of some novel membrane preparation routes. A one-step preparation route of homogenous exchange membranes by polyacylation of ionized monomers was developed in our lab. The ATRP technology was used to manipulate the structure of ion exchane membranes to achieve the constrcution of hydrophobic structure in the main chain and hydropholic in the side chain by controlling graft density and graft length of the side-chain pendant. The prepared membranes by this strategy will meet the demands of different applications. The indutrial preparation of this kinds of ion exchange membranes can breakthourgh the technological embargoes and price monopoly the Japan of leaded developed country and can achieve development of the independent intellectual property rights in exchange membranes production. The preparation route is very simple and effective with a moderate operation condition. The quarternization and sulfonation steps were avoided in our preparation route with a simplified preparation steps and a reduced pollution. Our preparation route meets with the demand of high-effective membranes in diffusion dialysis，conventional electrodialysis and bipolar membranes electrodialysis. The prepared membranes were tested with satisfactory results in many different processes such as special wastewater treatment，organic acids production，amino acid separation and purification，and heavy metal wastewater treatment.
To produce high performance polymer microfiltration/ultrafiltration (MF/UF) membranes with lower production cost， the amphiphilic copolymers and their corresponding blend membrane were presented and investigated. A series of amphiphilic copolymers with different compositions and sequence structures were synthesized via living radical polymerization. The synthesized copolymers were blended into various membranes via phase inversion process. It was found that， during the phase inversion process， amphiphilic copolymer migrated spontaneously to the membrane surface， resulting the enrichment of hydrophilic components in surface layer. This hydrophilic layer provided the membranes with improved hydrophilicity and fouling resistance. Meanwhile， the better compatibility between polymer base and hydrophobic components prevented the loss of amphiphilic copolymers in real application of the blend membranes. Based on the fundamental in structures and properties of the blend membranes， large-scale preparation of amphiphilic polymers and corresponding MF/UF blend membranes were achieved. The produced blend microporous membranes have been widely used in various areas including water purification， wastewater treatment and medical filtering， etc.
Smart polymeric gating membranes are composed of smart polymers and non-stimuli-responsive substrate membrane. The smart membranes can automatically change the hydrophilicity/hydrophobicity on the surface as well as trans-membrane permeability and selectivity in response to the environmental stimuli， which is attributable to the stimuli-responsive variation of hydrophilicity/hydrophobicity and configuration of the smart polymers in the membrane. Smart polymeric gating membranes are used for anti-fouling filtration， affinity separation， “on/off” control of enzyme reaction and controlled release， etc. The way to prepare such membranes affects the important parameters of smart polymeric gating membranes， such as the stimuli-responsive characteristics， stability and reproducibility. There are three kinds of preparation methods to fabricate the smart polymeric gating membranes according to when the smart polymers are added into the membrane materials. They are the methods introducing smart polymers by the modification of substrate membranes materials after membrane preparation， by the modification of substrate membrane materials before membrane preparation and by blending smart polymers during the membrane preparation. The definitions， subcategory， mechanisms and new advances of these preparation methods are introduced separately， and their advantages and disadvantages are addressed. The method that introduces smart polymers by the modification of substrate membranes materials after membrane preparation is the most widely employed to form the smart polymeric gating membranes. However， the method that blends smart polymers during the membrane preparation has great potentials to the mass production of smart polymeric gating membranes in the future. This paper will provide valuable guidance for the efficient preparation of smart polymeric gating membranes with stable and satisfactory stimuli-responsive characteristics.
Biomimetics and bioinspiration strategy has achieved important advances in many fundamental and engineering science areas. A variety of biomimetic and bioinspired membranes with high performance have been designed and prepared by imitating the different compositions， delicate structures， mild formations and exceptional functions of biological materials in nature. These membranes have found broad applications in water treatment， gas separation and organic liquid mixture separation. Through imitating or inspired by the prototypes of cell membrane， lotus leaf and mussel， biomimetic and bioinspired membranes are fabricated by biomineralization， bioadhesion， and self-assembly methods to achieve the goal of green， high-efficiency and energy-saving. These membranes will play more and more important roles in efficient use and sustainable development in resources and energy， and is going to be an important branch in membrane and membrane process. This article will briefly summarize the recent progress in biomimetic and bioinspired membranes， especially the preparation and application of antifouling membranes， hybrid membranes and composite membranes.