Preparation of MOFs/chitosan positively charged nanofiltration membrane by electrospray method
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摘要: 将壳聚糖的直接成膜性与电喷雾技术结合，并引入金属有机骨架（MOFs），制备了胺基修饰的UIO-66(Zr) NH2-UIO-66(Zr)/壳聚糖荷正电纳滤膜，实现对Ni2+的高效分离和富集。通过电喷雾技术可有效解决传统壳聚糖纳滤膜成膜周期长、膜层较厚、通量较低等问题。实验表明，与传统涂覆工艺相比，电喷雾法制备的壳聚糖复合膜在保持较高截留率的情况下，渗透性提高了634%。然而，单一壳聚糖基质膜受trade-off效应影响，分离性能难以进一步提升。引入NH2-UIO-66(Zr)作为填料可有效缓解trade-off效应，所制备的复合膜在不牺牲截留率的情况下，通量进一步提升38%（水通量为4.7×10−5 L·m−2·h−1·Pa−1，对NiCl2截留率为92%）。Abstract: Electrospray technology can solve the problems of long membrane formation period, thicker membrane layer and low flux of traditional chitosan nanofiltration membranes. In this study, the NH2-UIO-66(Zr)/chitosan positively charged nanofiltration membrane based on NH2-UIO-66(Zr)/chitosan was successfully prepared by combining the direct membrane-forming properties of chitosan with electrospray technology and introducing metal-organic frameworks (MOFs). This membrane has achieved efficient separation and enrichment of Ni2+. The morphology, structure and properties of membrane were investigated by SEM, EDS, Zeta potential, water contact angle measurements, etc. The results showed that compared with the traditional coating process, the permeability of the chitosan composite membrane prepared by the electrospray method was increased by 634% and the membrane can still maintain a good rejection. However, pure chitosan matrix membranes are usually affected by trade-off effect, and it is difficult to further improve the separation performance. The introduction of NH2-UIO-66 (Zr) as a filler can effectively alleviate the trade-off effect. Hybridization improved the hydrophilicity of the separation layer and formed a special membrane surface structure, thereby increasing permeability of the composite membrane. Experiments showed that the limit of NH2-UiO-66(Zr) loading was 5 wt% (the ratio of MOFs to chitosan). The optimized NH2-UIO-66(Zr)/chitosan membrane had a higher flux than pristine chitosan membrane (increased by 38%). The prepared membrane exhibited a high NiCl2 rejection of 92% and a water permeability of 4.7×10−5 L·m−2·h−1·Pa−1 (test pressure: 4×105 Pa; feed concentration: 0.5 g/L). In addition, the hybrid membrane exhibited excellent mechanical strength and had the potential to separate a single solution of MgCl2, ZnCl2 and Pb(NO3)2.
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Key words:
- chitosan /
- metal-organic framework /
- nanofiltration membrane /
- electrospray
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图 1 NH2-UIO-66(Zr)的结构图(a, b)及结构式(c)
Figure 1. Schematic (a, b)and structural formula (c) of NH2-UIO-66(Zr).
图 2 电喷雾法制备MOFs/壳聚糖膜示意图
Figure 2. Schematic diagram of MOFs/chitosan membrane prepared by electrospraying
图 3 NH2-UIO-66(Zr)的XRD谱图(a)、 FT-IR光谱(b)、UV-vis DRS(c)光谱以及SEM图(d)
Figure 3. XRD pattern(a), FT-IR spectrum(b), UV-vis DRS spectrum(c) and SEM image(d) of NH2-UIO-66(Zr)
图 4 PSF基底(a)，MCS-0膜(b)和MCS-5膜(c)的SEM图
Figure 4. SEM images of PSF substrate(a), MCS-0 membrane(b) and MCS-5 membrane(c)
图 5 PSF基底(a)，MCS-0(b)和 MCS-5膜(c)的水接触角测试
Figure 5. Water contact angle test of PSF substrate(a), MCS-0(b) and MCS-5 membrane(c)
图 6 PSF基底，CS膜和MCS-5膜的ATR-FTIR光谱
Figure 6. ATR-FTIR spectra of PSF substrate, chitosan membrane and MCS-5 membrane
图 8 不同注射速率的壳聚糖膜分离性能（0.5 g/L, 4×105 Pa）
Figure 8. Separating performance of chitosan membranes with different spraying speed (0.5 g/L, 4×105 Pa)
图 9 负载量对MCS膜分离性能的影响（0.5 g/L, 4×105 Pa）
Figure 9. Effect of loadings on the separation performance of MCS membrane (0.5 g/L, 4×105 Pa)
图 10 不同工艺制备的膜分离性能对比（0.5 g/L, 4×105 Pa）
Figure 10. Comparison of separation performance of membranes prepared by different processes (0.5 g/L, 4×105 Pa)
图 11 进料浓度（4×105 Pa）(a)和测试压力（0.5 g/L）(b)对MCS-5分离NiCl2的影响
Figure 11. Effect of feed concentration (4×105 Pa) (a) and test pressure (0.5 g/L) (b) on the separation performance of MCS-5 on NiCl2 solution
图 12 MCS-5膜对不同重金属的分离性能（0.5 g/L, 4×105 Pa）
Figure 12. Separation performance of MCS-5 membrane for different heavy metals (0.5 g/L, 4×105 Pa)
表 1 样品的Zeta电位测试
Table 1. Zeta potential test of samples
Item Zeta potential
（pH=4）/mVZeta potential
（pH=6）/mVZeta potential
（pH=8）/mVPSF −15.1±0.4 −30.88±0.82 −39.06±0.42 MCS-0 8.85±0.32 7.33±0.35 4.05±0.02 MCS-5 7.34±0.37 6.14±0.01 3.86±0.02 
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[1] ZHOU M Y, ZHANG P, FANG L F, et al. A positively charged tight UF membrane and its properties for removing trace metal cations via electrostatic repulsion mechanism[J]. Journal of Hazardous Materials, 2019, 373: 168-175. doi: 10.1016/j.jhazmat.2019.03.088 [2] PEYDAYESH M, MOHAMMADI T, NIKOUZAD S K. A positively charged composite loose nanofiltration membrane for water purification from heavy metals[J]. Journal of Membrane Science, 2020: 611. [3] ZHANG Y, ZHANG S, CHUNG T S. Nanometric graphene oxide framework membranes with enhanced heavy metal removal via nanofiltration[J]. Environmental Science and Technology, 2015, 49(16): 10235-10242. doi: 10.1021/acs.est.5b02086 [4] 曾行, 杨座国. 氧化石墨烯的制备及其负载纳滤膜性能[J]. 华东理工大学学报(自然科学版), 2018, 44(5): 644-649. [5] 崔秋花, 许振良, 潘鹤林, 等. 纳滤膜脱除稀盐酸中Ca2+和Mg2+[J]. 华东理工大学学报(自然科学版), 2020, 46(1): 10-15. [6] YAN C, ZHANG S H, LIU C, et al. Preparation, morphologies, and properties of positively charged quaternized poly(phthalazinone ether sulfone ketone) nanofiltration membranes[J]. Journal of Applied Polymer Science, 2009, 113(3): 1389-1397. doi: 10.1002/app.30143 [7] YU L, ZHANG Y T, WANG Y M, et al. High flux, positively charged loose nanofiltration membrane by blending with poly (ionic liquid) brushes grafted silica spheres[J]. Journal of Hazardous Materials, 2015, 287: 373-383. doi: 10.1016/j.jhazmat.2015.01.057 [8] YU L, DENG J M, WANG H X, et al. Improved salts transportation of a positively charged loose nanofiltration membrane by introduction of poly(ionic liquid) functionalized hydrotalcite nanosheets[J]. Acs Sustainable Chemistry and Engineering, 2016, 4(6): 3292-3304. doi: 10.1021/acssuschemeng.6b00343 [9] XU P, WANG W, QIAN X M, et al. Positive charged PEI-TMC composite nanofiltration membrane for separation of Li+ and Mg2+ from brine with high Mg2+/Li+ ratio[J]. Desalination, 2019, 449: 57-68. doi: 10.1016/j.desal.2018.10.019 [10] CHEN Q, YU P P, HUANG W Q, et al. High-flux composite hollow fiber nanofiltration membranes fabricated through layer-by-layer deposition of oppositely charged crosslinked polyelectrolytes for dye removal[J]. Journal of Membrane Science, 2015, 492: 312-321. doi: 10.1016/j.memsci.2015.05.068 [11] GU K F, WANG S H, LI Y H, et al. A facile preparation of positively charged composite nanofiltration membrane with high selectivity and permeability[J]. Journal of Membrane Science, 2019, 581: 214-223. doi: 10.1016/j.memsci.2019.03.057 [12] LIU F, MA B R, ZHOU D, et al. Positively charged loose nanofiltration membrane grafted by diallyl dimethyl ammonium chloride (DADMAC) via UV for salt and dye removal[J]. Reactive and Functional Polymers, 2015, 86: 191-198. doi: 10.1016/j.reactfunctpolym.2014.09.003 [13] KUMAR R, ISMAIL A F, KASSIM M A, et al. Modification of PSf/PIAM membrane for improved desalination applications using Chitosan coagulation media[J]. Desalination, 2013, 317: 108-115. doi: 10.1016/j.desal.2013.03.008 [14] KUMAR R, ISLOOR A M, ISMAIL A F, et al. Polysulfone-Chitosan blend ultrafiltration membranes: preparation, characterization, permeation and antifouling properties[J]. Rsc Advances, 2013, 3(21): 7855-7861. doi: 10.1039/c3ra00070b [15] MA X H, YANG Z, YAO Z K, et al. A facile preparation of novel positively charged MOF/chitosan nanofiltration membranes[J]. Journal of Membrane Science, 2017, 525: 269-276. doi: 10.1016/j.memsci.2016.11.015 [16] HE Y T, MIAO J, CHEN S Q, et al. Preparation and characterization of a novel positively charged composite hollow fiber nanofiltration membrane based on chitosan lactate[J]. Rsc Advances, 2019, 9(8): 4361-4369. doi: 10.1039/C8RA09855G [17] ZHU F, ZHENG Y M, ZHANG B G, et al. A critical review on the electrospun nanofibrous membranes for the adsorption of heavy metals in water treatment[J]. Journal of Hazardous Materials, 2021, 401: 123608. [18] CHOWDHURY M R, STEFFES J, HUEY B D, et al. 3D printed polyamide membranes for desalination[J]. Science, 2018, 361(6403): 682-685. doi: 10.1126/science.aar2122 [19] MA X H, YANG Z, YAO Z K, et al. Interfacial polymerization with electrosprayed microdroplets: Toward controllable and ultrathin polyamide membranes[J]. Environmental Science and Technology Letters, 2018, 5(2): 117-122. doi: 10.1021/acs.estlett.7b00566 [20] MA X H, GUO H, YANG Z, et al. Carbon nanotubes enhance permeability of ultrathin polyamide rejection layers[J]. Journal of Membrane Science, 2019, 570: 139-145. [21] GUILLERM V, KIM D, EUBANK J F, et al. A supermolecular building approach for the design and construction of metal-organic frameworks[J]. Chemical Society Reviews, 2014, 43(16): 6141-6172. doi: 10.1039/C4CS00135D [22] YIN N, WANG K, WANG L Z, et al. Amino-functionalized MOFs combining ceramic membrane ultrafiltration for Pb (II) removal[J]. Chemical Engineering Journal, 2016, 306: 619-628. doi: 10.1016/j.cej.2016.07.064 [23] NIK O G, CHEN X Y, KALIAGUINE S. Functionalized metal organic framework-polyimide mixed matrix membranes for CO2/CH4 separation[J]. Journal of Membrane Science, 2012, 413: 48-61. [24] CAO J L, SU Y L, LI Y N, et al. Self-assembled MOF membranes with underwater superoleophobicity for oil/water separation[J]. Journal of Membrane Science, 2018, 566: 268-277. doi: 10.1016/j.memsci.2018.08.068 [25] ZHAO H, YANG X, XU R, et al. CdS/NH2-UiO-66 hybrid membrane reactors for the efficient photocatalytic conversion of CO2[J]. Journal of Materials Chemistry A, 2018, 6(41): 20152-20160. doi: 10.1039/C8TA05970E [26] WANG N X, ZHANG G J, WANG L, et al. Pervaporation dehydration of acetic acid using NH2-UiO-66/PEI mixed matrix membranes[J]. Separation and Purification Technology, 2017, 186: 20-27. doi: 10.1016/j.seppur.2017.05.046 [27] ZHAO Y Y, LIU Y L, WANG X M, et al. Impacts of metal-organic frameworks on structure and performance of polyamide thin-film nanocomposite membranes[J]. Acs Applied Materials and Interfaces, 2019, 11(14): 13724-13734. doi: 10.1021/acsami.9b01923 [28] SU Y, ZHANG Z, LIU H, et al. Cd0.2Zn0.8S@UiO-66-NH2 nanocomposites as efficient and stable visible-light-driven photocatalyst for H2 evolution and CO2 reduction[J]. Applied Catalysis B-Environmental, 2017, 200: 448-457. doi: 10.1016/j.apcatb.2016.07.032 [29] HAO X Q, JIN Z L, YANG H, et al. Peculiar synergetic effect of MoS2 quantum dots and graphene on metal-organic frameworks for photocatalytic hydrogen evolution[J]. Applied Catalysis B-Environmental, 2017, 210: 45-56. doi: 10.1016/j.apcatb.2017.03.057 [30] SHEN L J, LIANG S J, WU W M, et al. CdS-decorated UiO-66(NH2) nanocomposites fabricated by a facile photodeposition process: an efficient and stable visible-light-driven photocatalyst for selective oxidation of alcohols[J]. Journal of Material Chemistry A, 2013, 1(37): 11473-11482. doi: 10.1039/c3ta12645e [31] WEN G, GAO X Y, GUO Z G. Simple fabrication of a multifunctional inorganic paper with high efficiency separations for both liquids and particles[J]. Journal of Material Chemistry A, 2018, 6(43): 21524-21531. doi: 10.1039/C8TA08782B [32] ZHU J Y, HOU J W, YUAN S S, et al. MOF-positioned polyamide membranes with a fishnet-like structure for elevated nanofiltration performance[J]. Journal of Material Chemistry A, 2019, 7(27): 16313-16322. doi: 10.1039/C9TA02299F [33] HE M L, WANG L, LV Y T, et al. Novel polydopamine/metal organic framework thin film nanocomposite forward osmosis membrane for salt rejection and heavy metal removal[J]. Chemical Engineering Journal, 2020, 389: 124452. [34] ZHANG H, TAYMAZOV D, LI M P, et al. Construction of MoS2 composite membranes on ceramic hollow fibers for efficient water desalination[J]. Journal of Membrane Science, 2019, 592: 117369. [35] JIRARATANANON R, SUNGPET A, LUANGSOWAN P. Performance evaluation of nanofiltration membranes for treatment of effluents containing reactive dye and salt[J]. Desalination, 2000, 130(2): 177-83. doi: 10.1016/S0011-9164(00)00085-0 -
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