共价有机框架化合物是一类结晶性的有机多孔材料，基于可逆化学反应将功能单元以共价键的形式连接成高度有序的多维结构，在气体分离、光电、催化等方面广受关注。将COFs制成薄膜材料，可用于膜分离、光电、传感、能量存储等领域，具有重要应用价值。本文首次采用喷涂层层自组装法、蒸发/喷涂层层自组装法、化学气相沉积法等可控制备COFs膜，研究制备过程中膜生长和控制机理，研究其分子分离性能。吸附功能膜是指键合吸附功能基团或者负载吸附剂颗粒的多孔膜，是一种较为新颖的吸附材料，主要用于水溶性微量污染物的富集，具有吸附/脱附速率快、处理效率高、能耗低、易于实现放大、吸附剂流失率低、便于回收等优点。本文制备了层状双金属氢氧化物混合基质膜用于吸附磷，聚偏氟乙烯接枝咖啡酸PVDF-g-CA/PB/PVDF膜用于吸附Cs⁺，PVDF/C18/PTFE固相萃取膜用于萃取回收苯酚，研究膜制备影响因素、静态吸附、动态吸附以及重复使用性能等。主要研究内容及结论如下：

（1）通过喷涂层层自组装方法制备COF-LZU1膜。交替喷涂均苯三甲醛和对苯二胺的1,4-二氧六环溶液至PAN基膜上，制得COF-LZU1复合膜，并应用于染料/水体系的分离，研究了乙酸浓度、自组装层数、反应温度及单次负载量对膜通量及截留率的影响，同时评价了膜的稳定性能。COF-LZU1膜的合成为醛胺缩合反应，在该反应中，对苯二胺的孤对电子进攻均苯三甲醛的羰基发生亲核加成，乙酸的催化作用是提高羰基亲核加成的活性快速得到半缩醛胺(-C(OH)(NHR)-)中间体，然后消除一分子水得到亚胺产物。乙酸在COF合成过程中起重要作用。实验结果表明，在一定酸度范围内，随着酸度的增加（0 M, 1 M, 3 M），反应速度加快，粒子粒度逐渐减小，膜表面致密光滑，截留率增加。随着组装层数增加，PAN基膜表面孔被完全覆盖，通量减小，截留率增加。而随着反应温度的升高，溶剂二氧六环挥发速度增加，不利于形成均一致密COF-LZU1层，使膜的截留率降低。在室温、3 M乙酸催化下制得的3层COF-LZU1复合膜对水溶性苯胺蓝的截留率大于99%，通量约为407.6 L m² h^-1 MPa^-1，该膜在超声条件下保持稳定，且长期运行性良好。该膜对其它几种不同的染料的截留率均在90%以上，表明该膜具有优异的纳滤性能和良好的应用前景。

（2）采用蒸发/喷涂层层自组装方法构建COF-LZU1膜。交替蒸发对苯二胺粉末和喷涂均苯三甲醛溶液至改性的PAN基膜上，制得多层COF-LZU1复合膜，并应用于染料/水体系的分离。研究了蒸发温度及时间、纳滤膜层数及单次负载量对膜通量及截留率的影响，并对膜的运行稳定性进行了评价。SEM、FTIR和XRD的分析表明，在基膜上制备了良好的COF-LZU1分离层。蒸发温度升高，膜表面COF-LZU1粒子粒径逐渐降低且膜表面逐渐分布均匀，在100 ℃蒸发制得的膜表面最致密均匀，对染料截留率最高。而随着蒸发时间的增加，膜表面的粒子越来越均匀致密，截留率升高，但蒸发时间过长（超过6 h）时可能会引起副反应的发生，使得截留率降低。最佳条件下（100 ℃条件下蒸发6 h，自组装层数为3层）制得的COF-LZU1复合膜对水溶性苯胺蓝的截留率为97.12%，通量约为529.9 L m² h^-1 MPa^-1，且长期运行稳定。该纳滤膜对几种不同的染料的截留率均在90%以上，该膜浸泡在乙醇、丙酮、二氯甲烷、乙酸乙酯等有机试剂中一段时间后纳滤性能保持不变，证明其具有良好的耐有机溶剂性能。

（3）通过化学气相沉积法制备COF-TpPa1膜。同时蒸发对苯二胺和三醛基间苯三酚固体，通过化学气相反应在改性的PVDF基膜上制得COF-TpPa1膜，并应用于染料/水体系的分离。研究了蒸发温度、蒸发时间、抗氧化剂铁粉量、不同PVDF基膜孔径对膜通量及截留率的影响，并对膜的运行稳定性进行了评价。实验结果表明，蒸发温度是蒸发气相法中的重要变量，随着加热温度的升高（180-240 ℃），单位时间内反应单体由固态升华为气态的量增加，反应物分压提高，气相反应速率、成核生长速率和沉积速率增加，截留率增加。随着蒸发时间的增加（2-30 min），膜表面孔隙明显减少，在20 min时膜表面形貌及截留率不再发生明显变化。同时探究了基膜孔径对膜性能的影响，随着孔径的减小(0.45 μm, 0.22 μm, 0.1 μm, 0.02 μm)，复合膜对染料的截留率增加，而通量下降。在220 ℃温度下蒸发20 min制得的复合膜（0.02 μm)对罗丹明B的截留率为96.37%，通量为 458.60 L m^-2 h^-1 MPa^-1，且长时间运行稳定。该纳滤膜对几种不同的染料的截留率均在90%以上，而对无机盐离子表现出较低的截留率，证明COFs膜可用于纯化含盐的染料产品。

（4）通过共沉淀法制备了Fe-Mg-Al三元层状氢氧化物，剥离后与PES混合制成了Fe-Mg-Al LDH/PES混合基质多孔膜，用于吸附水中的磷。研究了剥离方法及凝胶浴浓度对吸附容量的影响。甲酰胺可剥离LDH粉末，使其具有更好的吸附能力，引入羧甲基纤维素钠分散剂可以缩短剥离时间。随着凝胶浴中PES质量分数增加，膜上的孔径不断减小且致密均匀；当凝胶浴中PES质量分数占10%时所制得膜孔均匀且致密，吸附效果最好。同时研究了膜的静态吸附、动态吸附、洗脱、膜的重复利用等。研究表明，Fe-Mg-Al LDH混合基质膜吸附效果好，吸附容量达到59.88 mg g^-1，且具有重复利用性。

（5）分别采用一步光照法、UV光预活化/光引发聚合两步法和UV光预活化/加热引发聚合两步法在PVDF分子上接枝咖啡酸，并比较了这三种方法的优缺点。通过红外、酸碱滴定法测定接枝率，发现UV光预活化/加热引发两步法的接枝率最高，在最佳条件下，接枝率可达到76.3%。将接枝产物制成吸附功能膜，对Cs⁺表现出良好的吸附性能（0.23 mmol g^-1），Cs⁺/Li ⁺，Cs⁺/Na⁺和Cs⁺/K⁺的理想选择性分别为8.46、3.68和3.23。采用Fe(Ⅲ)-草酸络合物转化法制备普鲁士蓝纳米晶，通过过滤/非溶剂蒸气诱导相分离法制备PVDF-g-CA/PB/PTFE Sandwich结构吸附功能膜用于铯的吸附，研究了制膜条件（空气湿度、PB含量和PVDF-g-CA浓度）对膜形态、滤速和吸附容量的影响，研究了膜的静态吸附、动态吸附、解吸和重复利用等性能，发现该膜对Cs⁺表现出良好的吸附性能（0.07 mmol g^-1），Cs⁺/Li⁺、Cs⁺/Na⁺和Cs⁺/K⁺的理想选择性达到15.38、44.31和27.33，膜吸附等温线可以用Langmuir吸附模型很好地描述，NH₄Cl/HCl溶液表现出优异的洗脱效果，重复使用4次性能未见明显降低，表明该膜在铯吸附中具有一定实用价值。

（6）以硅溶胶、尿素、甲醛和去离子水为原料，采用硅珠堆积法合成了硅胶多孔微球；采用化学修饰法将十八烷基三氯硅烷键合到硅胶微球上，并以三甲基氯硅烷进行封尾，制得十八烷基硅胶键合相。首次采用过滤/非溶剂蒸汽沉淀法制备了聚偏氟乙烯/C18/聚四氟乙烯固相萃取膜，用于溶液中微量苯酚的固相萃取。低湿度下下制得的PVDF膜表面致密，水蒸气浓度低，其向湿膜渗透导致的相转化速率慢，成膜以溶剂蒸发机理为主，膜孔小，结构较致密。高湿度下（>40% RH），相转化由水蒸气向湿膜渗透为主要机理，膜孔大，结构较疏松。同时研究了PVDF溶液浓度、C18含量、苯酚溶液体积、过滤速率、NaOH洗脱液浓度对回收率的影响。结果表明，在高分子浓度为6%，C18含量为0.03 g，苯酚初始体积为100 mL，洗脱剂NaOH浓度为1 mol L^-1，富集系数为10时，回收率可达到100.02%，过滤速度（5-50 mL min^-1）对回收率影响不大，对实际自来水样品测定了苯酚的加标回收率，过滤速度为20 mL min^-1时，回收率为99.39%，标准偏差为0.63%，表明该膜具有优异的萃取性能和良好的应用前景。

Covalent Organic Framework (COF) is a type of crystalline organic porous material, and widely used in gas storage, separation, catalysis, and so on. Based on reversible chemical reactions, functional units are connected by covalent bonds into a highly ordered multidimensional structure. Recently, there has been escalating interest in developing COF membranes for molecular separation due to their narrow pore size distribution, diverse structures, and robustness. Nevertheless, COF powders are insoluble in common solvents and cannot be melted either. Thus, the preparation of COF membranes remains a great challenge. In this paper, the spraying layer-by-layer self-assembly method, evaporation/spraying layer-by-layer method, and chemical vapor deposition method were used to prepare COFs membranes, and the membrane growth and control mechanism of the preparation process were studied, and the molecular separation performance was also evaluated. Adsorption functional membrane refers to a porous membrane that binds adsorption functional groups or supports adsorbent particles. It is a relatively novel adsorbent material and mainly used for the enrichment of water-soluble trace pollutants. It has fast adsorption/desorption rates, high processing efficiency, low energy consumption, easy amplification, low adsorbent loss rate, and easy recovery. In this paper, LDH mixed matrix membrane, polyvinylidene fluoride grafted caffeic acid membrane, C18 solid phase extraction membrane were prepared and used to adsorb PO₄^3- , Cs⁺, and phenol, respectively. The influencing factors of membrane preparation, static adsorption, dynamic adsorption and recycled performance were studied. The main research contents and conclusions are listed as follows: 

(1) COF-LZU1 composite membranes were prepared by a stoichiometric spraying layer-by-layer self-assembly method for the first time, in which p-phenylenediamine and 1,4-dioxane with stoichiometric ratio were alternately sprayed onto alkaline modified PAN membrane. The effects of acetic acid concentration, membrane layers, and reactant concentrations were studied, and the stability of the membrane was also evaluated. In the reaction, the unshared electron pairs of the nitrogen atom of PDA attack the positively charged carbon atom on C=O of TFB, and acetic acid acts as the catalyst and increases the nucleophilic addition activity of C=O and generates the hemiacetal intermediate, followed by the removal of water and the formation of imine bonds. HAc plays an important role in the aldehyde/amine condensation reaction. The rejection slightly increased with the increasing HAc concentration, while the permeance gradually decreased because of the densification of the membranes. As the layers number increased, the surface pores of the PAN base membrane were completely covered, the flux decreased, and the rejection rate increased. With the increasing reaction temperature, the volatilization rate of the solvent dioxane increased, which is not conducive to the formation of a uniformly dense COF-LZU1 layer and the rejection reduced. It was found that COF-LZU1 membrane can efficiently reject different dyes (Mw 300-800) with rejection of >90% and permeability of 407 L m² h^-1 MPa^-1, suggesting great potential in molecule separation.

 (2) Evaporation/casting method was performed to fabricate COF-LZU1 membranes. p-Phenylenediamine powder and 1,3,5-benzenetricar boxaldehyde  solution were alternatively evaporated and cast onto polyacrylonitrile membrane to prepare COF-LZU1 membranes and employed for the separation of dyes. The effects of PDA evaporation temperature, time, layer number and reactant amount in each COF-LZU1 layer were studied, and the long-term operation was evaluated. As the evaporation temperature increased, the particle size of COF-LZU1 particles on the membrane surface gradually decreased and the membrane surface was gradually evenly distributed. The membrane surface obtained by evaporation at 100 ℃ was the densest with the highest rejection rate. As the evaporation time increased, the particles on the membrane surface became more and more uniform and dense, and the rejection rate increased. However, too long evaporation time(more than 6 h) may cause side reactions and reduced the rejection rate. The COF-LZU1 membranes showed remarkable rejection (>90%) for different dyes (Mw 350-800), low rejection (<8%) for salts and high solvent permeance (>500 L m ^-2 h ^-1 MPa ^-1). The nanofiltration performance remained unchanged after being immersed in organic reagents such as ethanol, acetone, dichloromethane, and ethyl acetate for a period of time, proving that it has good resistance to organic solvents. And The COF-LZU1 membrane also displayed excellent long-term operation stability, suggesting potential for rejection and desalination of dyes.

(3) The COF-TpPa1 membrane was prepared by chemical vapor deposition method. P-phenylenediamine and 2,4,6-trihydroxy-benzene-1,3,5 -tricarbaldehyde  were simultaneously evaporated onto modified poly(1,1-difluoroethylene) membrane in a chemical vapor deposition reactor to prepare COF-TpPa1 membranes for the separation of dyes. The effects of evaporation temperature, evaporation time, Fe powder amounts and pores size of PVDF membranes were studied, and the long-term operation was evaluated. Temperature plays an important role in the CVD method. With the rising temperature, the partial vapor pressure of the reactants increased, leading to increased reaction rate, nucleation and growth rate, and deposition rate. In the filtration of a 50 mg L^-1 rhodamine B (Mw =479.01, ca. 1.44 nm × 0.65 nm) solution, the rejection slightly increased while the permeance decreased. With the rising evaporation time, the pores size on the membrane surface reduced, and the rejection increased, while the permeance decreased significantly. As the pore size of PVDF membranes decreased, the resistance of pristine PVDF membranes in the filtration of water increased, and the flux declined, and the rejection to rhodamine B increased. The membranes showed an excellent water permeance of up to 400 L m^-2 h^-1 MPa^-1 with high rejection (> 90%) for different dyes (Mw 450-800), and low rejection (< 8.2%) for salts. The COF-TpPa1 membrane also displayed considerable long-term operation stability.

(4) Mg-Al-Fe layered double hydroxides were exfoliated and incorporated in polyether sulfone membranes for the removal of phosphate for the first time. The exfoliation methods, coagulation bath, LDH amount, interfering ions, adsorption isotherm, desorption and reuse of the membranes were investigated. It was found that LDHs could be quickly exfoliated in formamide/ N,N-dimethylformamide  solvent mixtures with sodium carboxymethyl cellulose as a stabilizer. The membranes displayed much higher adsorption capacity for phosphate (5.61 mg g^-1) and faster adsorption rate than the unexfoliated materials. With increased DMF content in the coagulation bath, the static and dynamic adsorption capacity rose. Interference from Cl^? and SO₄^2?(50 mg L^-1) on adsorption of phosphates was not apparent. The membranes displayed excellent reusability in dynamic adsorption/desorption. The membranes also showed high adsorption capacity for fluorides (1.61 mg g^-1).

(5) Caffeic acid was grafted on PVDF by UV pre-activation/thermal initiated grafting method with PVDF solution as substrates for the first time. The PVDF-g-CA was employed for fabrication of adsorptive membranes for cesium, and the static and dynamic adsorption, along with elution and membrane reusability, were studied. The results showed that, under the same concentrations and grafting time, the average grafting degree of UV preactivation/thermal initiated grafting method is much higher than that of the two-step UV grafting and the one-step UV grafting. The PVDF-g-CA membranes show high adsorption capacity for Cs⁺ (0.23 mmol g^-1, 25°C), and the selectivity factor of Cs⁺ vs. Li⁺ , Na⁺ and K⁺ is 8.46, 3.68 and 3.23. Furthermore，to intensify the membrane adsorption of cesium, Prussian blue nanoparticles were synthesized by Fe(III)-oxalic acid complex conversion. Then, the PVDF-g-CA/PB/polytetrafluoroethylene sandwich membranes were fabricated by filtration/nonsolvent vapor-induced phase separation for the first time. The effects of air humidity, polymer concentrations, and PB contents on the membrane morphology, flow rates and adsorption capacity were studied, and a series-resistance model was employed to describe the hydrodynamic resistances of the membranes. The results show that under optimized fabrication conditions, the maximum adsorption capacity of the membranes is 1.12 mmol m-² for Cs⁺, and the selectivity of Cs⁺ vs. Li⁺ , Na⁺ and K⁺ is 44.31, 15.38 and 27.33, respectively. The adsorption isotherm of Cs⁺ can be well described by the Langmuir model. The membrane resistance increased with increasing polymer concentrations and PB contents. The sandwich membranes exhibit excellent dynamic adsorption performance and reusability, indicating great potential for the adsorption of Cs⁺.

(6) Octadecylsilyl-bonded silica based novel solid phase extraction membranes were fabricated by nonsolvent vapor induced phase separation method for the first time, and employed for extraction trace phenol as a model. The effects of membrane fabrication conditions and extraction parameters on the recoveries were explored. Under the optimized fabrication conditions, the extraction recovery of phenol (0.02 mg L^-1, 100 mL) attains 100% with enrichment factor of 10. The spike recovery of real water samples reaches 97.67%-99.40% with standard deviation of 1.16%-1.42%, demonstrating great potential in solid phase extraction.