Shape Recovery Zwitterionic Bacterial Cellulose Aerogels with

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Shape Recovery Zwitterionic Bacterial Cellulose Aerogels with Superior Performances for Water Remediation Jingxian Jiang, Juan Zhu, Qinghua Zhang, Xiaoli Zhan, and Fengqiu Chen Langmuir, Just Accepted Manuscript • Publication Date (Web): 26 Mar 2019 Downloaded from http://pubs.acs.org on March 26, 2019

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Shape Recovery Zwitterionic Bacterial Cellulose Aerogels with Superior Performances for Water Remediation Jingxian Jiang, Juan Zhu, Qinghua Zhang*, Xiaoli Zhan, and Fengqiu Chen Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China ABSTRACT:

Severe water pollution has loaded heavy burden on the ecological

environment that human beings rely on. Effective approaches to mitigate this worldwide issue are in high demand. Here in this work, an organic-inorganic bacterial cellulose aerogel was fabricated through freeze-drying technique and step-by-step coating method. The as-prepared aerogel possessed intact three-dimensional porous structure, ultra-low density, and shape recovery performance. Ag2O nanoparticles were uniformly and firmly dispersed on the cellulose skeleton, endowing as-prepared aerogel with excellent photocatalytic degradation property of methylene blue and great recyclability. The zwitterionic compounds attached onto the aerogels through the effect of silane offered them with superhydrophilicity, superoleophilicity and underwater superoleophobicity as well as underoil superhydrophobicity. And aerogels could separate oil/water mixture with high efficiency. This environmentally friendly bacterial cellulose aerogel equipped with multifunctionality showed great potential in its wide 1

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application in water treatment fields. KEYWORDS: Bacterial cellulose aerogel, Ag2O nanoparticles, Zwitterionic compounds, Oil/water separation, Photocatalytic degradation INTRODUCTION The worldwide water crisis, which is mainly caused by population explosion, increasing urbanization, reduced forest coverage, environmental pollution, and irregular distribution of water resources, has evoked intensive public concerns recent years, for its serious threat on the survival and development of human society.1-2 In particular, aggravated water pollution heavily worsen the pervasive problem of water crisis.3-5 Organic dyes, which extensively exist in wastewater discharged from various kinds of industries including textiles, food, paper-making, pharmaceutical, require environmentally friendly and energy-efficient treatment methods.6-8 Oil pollutions that are usually caused by frequent oil spills and discharge of oily sewage from industry and livelihood need to be carefully disposed by effective oil/water separation technology.912

Conventional approaches such as chemical sedimentation, skimming, air flotation,

and adsorption usually suffer from inevitable disadvantages like single functional capability, possibility of secondary-pollution, unsatisfactory recyclability, high cost, complicated operation procedures and low efficiency, severely limiting their large-scale applications.13-14 Therefore, research and efforts should be dedicated in exploring advanced materials with higher efficiency, lower cost, integrated functionality and less negative impact on the environment to address these difficulties.15-19 Aerogels with 2


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macroscopically three-dimensional structure, ultra-low density, high porosity, and large specific area are excellent alternatives to inefficient traditional materials in the removal of contaminants in wastewater.20-24 Cellulose, the most abundant natural biomass material, has been found far-ranging applications in water treatment, energy storage and conversion, optical elements, wearable devices, tissue engineering and so on.25-27 Rich hydroxyl groups in cellulose molecules provide tremendous active sites for physical interaction and chemical reaction, making functions integration on them easily.28 As a green, sustainable and cost-effective raw material, cellulose can produce aerogels which possess many unparalleled advantages over synthesized polymer-based aerogels, carbon nanotubes and graphene-based aerogels.29 Superior properties like environmental friendliness, biocompatibility, and mechanical robustness make cellulose aerogels superb threedimensional skeletons for fabricating prominent materials used for water remediation.30-32 A great number of advanced cellulose aerogels have been developed aiming at pollutants removal from aquatic systems, and many breakthroughs have been achieved.33-35 Methods and technologies such as chemical vapor deposition (CVD), surface grafting, surface coating, pyrolysis and pretreatment of cellulose molecules were employed to realize modification of original cellulose aerogels.35-38 Compared with pure cellulose aerogels, organic-inorganic hybrid aerogels can combine unique natures of both cellulose skeletons and inorganic components. Ferroferric oxide (Fe3O4), titanium dioxide (TiO2), silicon dioxide (SiO2), hydroxyapatite, ferric hydroxide (Fe(OH)3) growing on or inserting into aerogel scaffolds endow cellulose aerogels with 3


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magnetism, photocatalysis, special wettability, and unique adsorption properties, further extending their application fields.39-45 However, the fabrication of organicinorganic hybrid aerogels always confronted inorganic components agglomeration and mechanical performance damage. Therefore, constructing robust organic-inorganic hybrid cellulose aerogels with excellent performance is of great significance. Bacterial cellulose is a typical kind of cellulose that equipped with common advantages and can be produced in large amounts by a microbial fermentation process.46 Compared with plant cellulose, bacterial cellulose is free from hemicelluloses, lignin and pectin, making it easy for further fabrication.47 Zwitterionic compounds, which contain oppositely charged groups in their molecules and exhibit an overall charge neutrality, have been viewed as an effective class of antibacterial and nonfouling materials.48-49 Through elaborate design, zwitterionic compounds can be applied in constructing multifunctional materials. In this work, we designed and fabricated an organic-inorganic composite cellulose aerogel by freeze-drying technique and step-by-step dip-coating method. This aerogel was capable of efficiently realizing oil/water separation and removing dyes from water medium by photocatalytic degradation. Bacterial cellulose was chosen as starting material and Ag2O was in situ formed and uniformly distributed on the cellulose skeleton, providing the Ag2O-loaded aerogel with superior visible light photocatalytic degradation performance. Zwitterionic compound was newly synthesized and firmly coated onto the Ag2O-loaded aerogel with the effect of silane, which was quite different from complicated grafting and polymerization methods. Besides, the organic-inorganic composite cellulose 4


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aerogel demonstrated good shape recovery property. The reusability of these performances was excellent. Therefore, these charming characteristics of the asprepared cellulose-derived aerogel make it a promising candidate for water remediation, especially for organic dyes and oily wastewater elimination. EXPERIMENTAL SECTION Materials. Bacterial cellulose with a diameter of 50-100 nm and a length larger than 20μm

was

bought

from

Guilin

Qihong

Co.,

Ltd.

(N,N-Dimethyl-3-

aminopropyl)trimethoxysilane (KH556) was obtained from Hubei Jusheng Technology Co., Ltd. Bromoacetic acid and aminoacetic acid were purchased from Aladdin Chemistry Co. Ltd. Glutaraldehyde 25% aqueous solution, acetonitrile and methylene blue were provided by Sinopharm Chemical Reagent Co., Ltd. Benzene, toluene, nhexane, cyclohexane and dichloromethane were obtained from Sinopharm Chemical Reagent Co., Ltd. The silver nitrate was bought from Shanghai Institute of Fine Chemical Materials. All reagents were used as received. And deionized water was used throughout the study. Synthesis of zwitterionic compound. KH556 (4.15 g, 0.02 mol) was added in 9.68 g of acetonitrile in a 50 ml, three-necked, round bottomed flask fitted with a nitrogen inlet and outlet. The excess bromoacetic acid (3.06 g, 0.022 mol) was dissolved in 7.13 g of acetonitrile separately, and then the mixture solution was poured into a constant pressure drip funnel that was set on the abovementioned flask. Before the reaction was started, the system was purged with N2 for 30 min. When the bromoacetic acid solution 5


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was added dropwise into the KH556 solution, the reaction was started to perform. And the reaction was continued for 36 h with stirring at 80 ℃. Then the light yellow solution was precipitated with abundant ice ether. The white sediment was dried in a 45 ℃ vacuum oven for 12 h. Then the zwitterionic compound was finally obtained. The mechanism of the reaction was shown in Scheme 1. This synthesis process was modified based on our previously published work.50

Scheme 1. Synthesis of the zwitterionic compound.

Preparation of Ag2O/zwitterionic compound-loaded bacterial cellulose aerogels (BCAZ aerogels). Bacterial cellulose membranes were cut into small pieces and added into 200 mL beakers with certain amount of deionized water to form 1 wt% mixture. The uniform fiber dispersions were obtained by homogenizing the mixtures for 30 min at 12,000-14,000 r.p.m. using a FSH-2A high speed homogenizer. Crosslinking agent glutaraldehyde was added into the mixtures during the homogenizing process. Subsequently, the dispersions were poured into molds and frozen in a -20℃ refrigerator for 3 h, followed by a freeze-drying procedure for 48 h to obtain the original bacterial cellulose aerogels. Then the bacterial cellulose aerogels were put into a 60 ℃ oven for 6


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12 h. The obtained bacterial cellulose aerogels were soaked into 100 mL of newly prepared AgNO3 solution with 1.2 g aminoacetic acid for 3 h. Three different concentrations (0.1 mol/L, 0.05 mol/L and 0.025 mol/L) of AgNO3 solutions were used. During the soaking process, the white cellulose aerogels were gradually turned into brown, further darkening as time went by. The saturated aerogels were frozen in a -20℃ refrigerator for 3 h again, and freeze-dried to get Ag2O-loaded aerogels (BCA aerogels). After this, the BCA aerogels were kept under ambient conditions to complete the Ag2O formation process. Finally, the BCA aerogels were immersed into 5 wt% zwitterionic compound solution (deionized water used as the solvent) and dried at a 120 ℃ for 3 h. Therefore, the fabrication process of the BCAZ aerogels was fully completed. Characterization. The FT-IR spectrum of the zwitterionic compound was obtained by using a Nicolet 5700 Fourier transform infrared (FTIR) instrument. The compound was dissolved in ethanol in advance and casted onto KBr disks for analysis. The chemical structures of the as-prepared aerogels were confirmed by the attenuated total reflection/Fourier transform infrared (ATR-FTIR, Nicolet 5700, ThermoFisher). And 32 scans were conducted for each spectrum at a resolution of 4.0 cm-1. The morphologies and microstructures of the as-prepared aerogels were studied by scanning electron microscopy (SEM). The SEM analysis was conducted on an S-570 scanning electron microscope (Hitachi) with an accelerating voltage of 5 kV. Prior to SEM analyzing, aerogel samples were gold sputtered. SEM-EDX (Energy dispersive X-ray, GENESIS4000, EDAX, USA) mapping was applied to demonstrate the presence and dispersion of Ag2O nanoparticles in the as-prepared BCAZ aerogel. 7


A mercury

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porosimeter (AutoPore IV 9500, Micromeritics, USA) was employed to investigate the porosity of the BCAZ aerogel. The surface wettability of aerogels was measured by sessile drop contact angle analysis with a SDC-100 optical contact-angle goniometer (SINDIN Co., Ltd., China) at room temperature. Oil/water separation performance. The BCAZ aerogel was fixed in the filtering apparatus to investigate its oil/water separation performance. For the separation of nhexane/water mixture, the BCAZ aerogel was pre-wetted by water in advance. A mixture of water and n-hexane was prepared by adding 15 mL n-hexane into 15 mL water, and n-hexane was dyed by Sudan Red Ⅰ. An apparent stratification phenomenon was observed in the mixture. Then the oil/water mixture was poured into the upper receiver of the filtering apparatus. The whole separation process was only driven by gravity, with water permeating through the BCAZ aerogel and n-hexane blocked. When there was no droplet dripped from the upper receiver, the filtrate in the lower receiver was collected. And the n-hexane after separation was gathered from the upper receiver too. Then for the separation of water/dichloromethane mixture, the BCAZ aerogel was pre-wetted by dichloromethane. The water/dichloromethane mixture was prepared by adding 15 mL water into 15 mL dichloromethane. Subsequently, the separation process was performed the same as the separation of n-hexane/water mixture. When the separation process was completed, dichloromethane was collected from the lower receiver of the filter apparatus, and water was collected from the upper receiver. Subsequently, the separation efficiency was determined by measuring the oil content in the filtrate after the separation test through the UV-vis absorption spectrometer. 8


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Photocatalytic degradation tests. The photocatalytic degradation performance of the BCAZ aerogel was investigated by the photo-degradation of 5 mg/L methylene blue solution (50 mL). 0.05 g of aerogel was used as catalyst in each photo-degradation test. Before light irradiation, the mixture containing aerogel and methylene blue was put in darkness with continuous stirring for 120 min to reach the adsorption equilibrium. A 300 W Xe lamp equipped with a cutoff filter of 420 nm was employed to simulate the visible light. The lamp was placed vertically 20 cm above the reaction system. Then the aqueous dye solution with the aerogel was illuminated under the simulated visible light for 3 h. 3 mL of dye solution was sampled for every 20 mins. The concentrations of dye samples were examined by the UV-vis spectrophotometer at λ=664 nm. The recycling stability of the photocatalytic degradation performance was evaluated through the same procedure. And 6 cycles were conducted. RESULTS AND DISCUSSION Bacterial cellulose was chosen as the building block for the BCAZ three-dimensional (3D) aerogel because of its low cost, easy fabrication, mechanical robustness and largescale production in industry.51-53 The abundant hydroxyl groups in its molecules make the cellulose fibers uniformly dispersed into water by homogenizer. The resulting cellulose nanofiber solution can be assembled into high-porous 3D aerogels by a freezedrying process. As evidenced by published articles, the dispersal-recombination process is extremely vital for the construction of bacterial cellulose aerogels with excellent elasticity.54 In our approach, 1 wt% bacterial cellulose solution was prepared to assemble 3D original cellulose aerogels (BC aerogel). The addition of glutaraldehyde 9


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and further heat treatment were aimed to realize chemical cross-linking to enhance the mechanical property of cellulose aerogels. The obtained white cellulose aerogel possessed the weight of 0.26 g in the volume of 19.63 cm3, and the ultra-low density could be calculated as 13.24 mg/cm3. In order to figure out a better recipe for Ag2O nanoparticles loading, three concentrations (0.1 mol/L, 0.05 mol/L, 0.025 mol/L) of silver nitrate/aminoacetic acid were prepared. The synthesis mechanism of Ag2O-anchored cellulose aerogel (BCA aerogel) can be concluded as follows.55 The Ag+ ions can react with aminoacetic acid to form the complex ion Ag(C2H5NO2)n+ at room temperature in aqueous solution. When the cellulose aerogel was immersed into the silver nitrate/aminoacetic acid mixture, the formed complex ions were combined with the cellulose aerogel owing to the abundant hydroxyl groups existed on the surface of cellulose aerogels. Then the Ag(C2H5NO2)n+ could further get Ag(C2H5NO2)n(OH)x(H2O)y. Subsequently, the Ag2O was gradually produced during the freeze-drying and ambient drying process. The color of the aerogels changed from white to brown, then to dark brown, which could be a strong evidence for the formation of Ag2O. The photocatalytic performance of the three kinds of Ag2O-loaded aerogels was evaluated to judge the suitable concentration of silver nitrate/aminoacetic acid mixture. As shown in Figure S1, the degradation degree of methylene blue increased gradually along with the time. Apparently, after two hours’ irradiation, methylene blue was degraded a lot by all these BCA aerogels. The aerogel fabricated by 0.025 mol/L silver nitrate/aminoacetic acid mixture showed a highest degradation efficiency of 92.68 %. Aerogels prepared from 0.1 mol/L and 0.05 mol/L 10


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silver nitrate/aminoacetic acid mixtures degraded MB dye for 40.18 % and 70.57 %, respectively. Therefore, it seemed like that a lower concentration of silver nitrate could produce a composite aerogel with a larger photocatalytic efficiency. Hence, the concentration of the silver nitrate/aminoacetic acid mixture was finally confirmed as 0.025 mol/L. The successful coating of zwitterionic compound onto the BCA aerogel was ascribed to the dehydration condensation effect of silane. As shown in Scheme 1, methoxyl groups were existed in the chemical structure of zwitterionic compound. Hydrolyzable groups in silanes can react with water to form silanols, which can further react with other silanols or the hydroxyl groups on the surface of solid materials.56-57 Herein, the formed silanols could react with the hydroxyl groups on the cellulose matrix. Therefore, the zwitterionic compound was loaded onto the BCA aerogel by the hydrolytic condensation of silanes. Finally, the ingenious designed BCAZ aerogel were completely constructed. The chemical structure of the newly synthesized zwitterionic compound was studied by FTIR, and the spectrum was shown in Figure S2. The peak at around 3423 cm-1 was ascribed to the stretching vibration of carboxylic O-H groups. The peak at 1626 cm-1 corresponded to the stretching vibration of C=O in carboxyl groups. And the peak representing C-Si vibration was observed at 1405 cm-1. The absorption bands at 1088 and 922 cm-1 were assigned to the characteristic vibrations of Si-O-C groups. 1H NMR spectrum was displayed in Figure S3. These results suggested that the designed 11


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zwitterionic compound was successfully synthesized. Besides, FTIR spectra of original bacterial cellulose (BC) aerogel, Ag2O-loaded cellulose (BCA) aerogel and Ag2O/zwitterionic compound-loaded (BCAZ) aerogel were recorded and shown in Figure 1. The absorption peaks at 3343 and 3337 cm-1 were assigned to the stretching and bending vibrations of O-H groups. The peaks at 1437 and 1162 cm-1 belonged to the asymmetric angular deformation of C-H bonds and the asymmetrical stretching of C-O-C glycoside bonds in bacterial cellulose molecules.32 In the spectrum of BC aerogel, the absorption peaks at 1107 cm-1 and those that were emphasized in pink shadow were ascribed to the stretching of C-OH and C-C-OH bonds in secondary and primary alcohols.58 After loading with Ag2O nanoparticles, the spectrum of BCA aerogel had changed. The observed peaks at 1492 and 1389 cm-1 corresponded to the O-H stretching vibration and the H-O-H bending vibration of the adsorbed water respectively.59 The distortion of bands suggested in pink shadow revealed the formation of hydrogen bonds between bacterial cellulose and Ag2O. The peak at 1617 cm-1 in the spectrum of BCAZ aerogel was derived from the stretching vibration of C=O bonds in carboxylic groups, indicating the successful loading of the newly synthesized zwitterionic compound.

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Figure 1. ATR-FTIR spectra of BC, BCA and BCAZ aerogels, respectively.

The microstructure of the prepared aerogels was investigated by using scanning electron microscopy (SEM). And SEM images were shown in Figure 2. As can be seen from these pictures, aerogels exhibited multiscale morphologies, from microscale to nanoscale. Figure 2a and e displayed the porous network structure of original BC aerogel and composite BCAZ aerogel, respectively. There was little difference between these two pictures, which suggested that the mild modification method did not affect the original three-dimensional structure of the BC aerogel microscopically. A compact surface without particles was displayed in Figure 2b, which represented the morphology of pore walls for BC aerogel. However, morphologies of pore walls changed significantly after loading with Ag2O nanoparticles, and varied with loading concentrations. When the concentration of silver nitrate was set as 0.1 mol/L, the Ag2O particles agglomerated heavily as shown in Figure 2c. When the concentration of silver nitrate was fixed at 0.05 mol/L, the Ag2O particles exhibited a slight agglomeration 13


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(Figure 2d). The aggregation of Ag2O nanoparticles on aerogel pore walls had adverse effect on the photocatalytic performance (Figure S1). Figure 2f showed the microstructure of pore walls for composite BCAZ aerogel. With a concentration of 0.025 mol/L for silver nitrate, Ag2O nanoparticles were uniformly dispersed onto the surface of pore walls. The homogeneous dispersion of Ag2O nanoparticles was beneficial for improving the photocatalytic property, as confirmed in Figure S1. In addition, the coating of zwitterionic compound had limited influence on the morphology of the prepared aerogels. Besides, the composite BCAZ aerogel had a high porosity of 91.15%. In order to further confirm that the Ag2O nanoparticles were uniformly dispersed on the BCAZ aerogel skeleton, elemental mapping images were also recorded in Figure 2. Figure 2g-j showed the mapping images of C, O, Si, and Ag elements, respectively. The presence of Si element verified that the zwitterionic compound was coated onto the BCZA aerogel. The dispersion of Ag element revealed the homogeneous loading of Ag2O nanoparticles again. Therefore, with the optimized raw material ratio, the composite BCAZ aerogel was equipped with a porous threedimensional structure with nanoparticles uniformly dispersed.

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Figure 2. SEM images of aerogels: (a,b) BC aerogel, (c,d) BCA aerogels with different silver nitrate concentrations (0.1 mol/L and 0.05 mol/L, respectively), (e,f) BCAZ aerogel. Elemental mapping images of BCAZ aerogel: (g) C element, (h) O element, (i) Si element, (j) Ag element, (k) Overlapping of C, O, Si, Ag elements. (l) EDS analysis of BCAZ aerogel (not all the elements were labeled here).

Surface wettability is of great significance for the comprehensive performance of materials. The surface wettability of BCAZ aerogel was investigated through static contact angle analysis and results were displayed in Figure 3. In air, when water 15


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contacted with the BCAZ aerogel, it spread out and permeated into the aerogel immediately. Similarly, when oil droplet contacted with the surface of the BCZA aerogel in air, it behaved the same way. Results of Figure 3a and b suggested that the BCAZ aerogel had a superhydrophilic and superoleophilic surface. If the water contact angle was tested under oil, things seemed to be very different. Because the aerogel was saturated with oil, the water droplet remained a quasi-spherical shape on the surface of BCAZ aerogel, with a contact angle larger than 150° (Figure 3c). When the aerogel was tilted a little, the water droplet would roll off very easily (Video S1). For many kinds of oil, they also displayed quasi-spherical state on the surface of BCAZ aerogel under water with contact angles larger than 150°, which meant that the BCAZ aerogel had underwater superoleophobicity (Figure 3d, e, f and g).

Figure 3. Wetting behavior of water and oil on the surface of BCAZ aerogel. (a) Water contact angle in air. (b) Oil (n-hexane) contact angle in air. (c) Water contact angle 16


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under oil. (d-g) Oil contact angle under water.

The special surface wettability of composite BCAZ aerogel endowed it with high efficient oil/water separation property, which was in urgent demand in water treatment field. Figure 4 showed the digital pictures of the oil/water separation progresses and results by using BCAZ aerogel. Pre-wetted by water, the BCAZ aerogel could be utilized to separate n-hexane/water mixture. It only took several seconds to complete the whole separation process (Figure 4a and b). As can be seen from Figure 4c and d, the filtrates collected from the upper receiver (n-hexane) and lower receiver (water) were so pure that no water droplet could be observed in oil solution and no oil droplet could be found in water. This suggested that the BCAZ aerogel could realize nhexane/water separation. However, if the BCAZ aerogel was pre-wetted by dichloromethane, it could be applied to separate water/dichloromethane mixture. Figure 4e and f displayed that when the liquid mixture was poured into the filter device, dichloromethane permeated through the BCAZ aerogel and water was blocked by it. The collected filtrates were clear and transparent, with no water droplet and dichloromethane mixed in (Figure 4g and h). For n-hexane/water separation, the separation efficiency was 99.22% for the first time, 99.08% and 99.06% for the second and third times, respectively. For the separation of water/dichloromethane, the separation efficiency was calculated as 99.42% for the first time, 99.21% and 99.13% for the second and third times, respectively. Therefore, the prepared composite BCAZ aerogel had the ability to realize oil/water separation effectively and quickly, showing 17


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great potential in oily wastewater treatment.

Figure 4. Digital pictures of oil/water separation by BCAZ aerogel: n-hexane/water mixture separation process (a-b) and results (c-d); water/dichloromethane mixture separation process (e-f) and results (g-h). Dichloromethane and n-hexane were dyed with Sudan Ⅰ in advance.

Besides, because of the loading of Ag2O nanoparticles, the BCAZ aerogel was equipped with superior photocatalytic property. The mechanism of photocatalytic performance for Ag2O nanoparticles has been well investigated. Due to the narrower band gap, Ag2O is easier to be excited by the irradiation of visible light. The photogenerated electrons move from the valence band (VB) to the conduction band (CB), leaving photogenerated holes remaining in the VB, which participate in the 18


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photocatalytic decomposition of attached organic pollutants.60-61 The photocatalytic performance of BCAZ aerogel was evaluated by the degradation of methylene blue (MB) solution under visible-light irradiation. As shown in Figure 5a, the concentration of MB solution was decreased with time. The color of MB solution was changed gradually from blue to light blue, and then to colorless. Approximately 90% of MB solution was degraded within 100 min. And when the degradation test under visiblelight irradiation was lasted for 180 min, the concentration of MB solution was as low as 3.41% of the original solution, indicating an ultra-high photo-degradation efficiency. Figure 2f had revealed that Ag2O nanoparticles were uniformly dispersed onto the pore walls of BCAZ aerogel. The homogeneous dispersion of Ag2O nanoparticles was conducive for improving the photocatalytic property of BCAZ aerogel. For the purpose of investigating the photocatalytic stability of BCAZ aerogel, cycling tests were performed and results were displayed in Figure 5b and c. The concentration of MB solution decreased with time gradually in every cycling test the same as the first cycle. Even after 6 cycles, the degradation rate of MB solution remained 97.8% of the first cycle, showing an actually good stability. High photo-degradation efficiency and good stability of BCAZ aerogel offered it with capability to deal with wastewater contaminated by organic dyes. In addition, the photocatalytic efficiency of as-prepared BCAZ aerogel was comparable to or higher than that of Fe3O4@cellulose aerogel nanocomposite, the silver and manganese co-doped titanium oxide aerogel, Ag2O/sodium alginate-reduced graphene oxide aerogel, and the 3D g-C3N4-agar hybrid aerogel.42, 62-64 19


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Figure 5. (a) Degradation curve of MB by using BCAZ aerogel under visible-light irradiation. Insert picture shows color changes for MB solution at different photodegradation times. (b) Six cycle degradation tests of MB by using BCAZ aerogel under visible-light irradiation. (c) Cycle degradation rates of MB by using BCAZ aerogel under visible-light irradiation.

With a self-supporting three-dimensional porous structure, the composite BCAZ aerogel possessed good shape recovery performance. As shown in Figure 6a, the small cubic piece of BCAZ aerogel could be compressed into a thin sheet that was displayed in Figure 6b. Then by immersing this aerogel sheet into water, it could absorb water easily, quickly, and recover to its original shape immediately (Figure 6c). This might be ascribed to its excellent water absorption capacity and performance of shape recovery. By compressing, water was squeezed out fast from the saturated aerogel, and the cubic aerogel turned to a thin sheet again. Each compression and recovery process could be defined as one cycle. Figure 6d, e and f gave the images of BCAZ aerogel pieces after going through the 2nd, 5th and 10th cycles. Results revealed that even after 10 cycles of compression and recovery, the aerogel could maintain its original shape 20


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with no noticeable changes in shape and volume. In order to further confirm the shape recovery property of the BCAZ aerogel, Figure S4 exhibited this property by absorbing water and Video S2 recorded that the BCAZ aerogel could recover its original state immediately in water even though went through large deformation. Therefore, the superior recovery performance promised wider application fields for the BCAZ composite aerogel.

Figure 6. Digital images of BCAZ aerogel for its shape recovery property. CONCLUSIONS In summary, a Ag2O/zwitterionic compound-loaded bacterial cellulose aerogel aiming to tackle water treatment problems was designed and fabricated by freeze drying 21


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technique and step-by-step dip-coating method. Ag2O nanoparticles were uniformly and firmly attached onto the cellulose skeleton, which was conductive to the excellent photo-degradation of organic dyes. The superhydrophilicity, superoleophilicity in air and underwater superoleophobicity as well as underoil superhydrophobicity offered asprepared aerogel with ability to realize efficient oil/water separation. What’s more, the shape recovery property of this aerogel that was indicative of its good mechanical performance gave it opportunities to serve in wider application fields. Therefore, the as-prepared multifunctional cellulose aerogel showed great potential for its usage in complex water remediation. ASSOCIATED CONTENT Supporting Information Degradation curves of MB by Ag2O-loaded cellulose aerogels under visible-light irradiation, FTIR spectrum of the newly synthesized zwitterionic compound, 1H NMR spectrum of the zwitterionic compound, shape recovery property of BCAZ aerogel by absorbing water (PDF). Water droplet easily rolls off from the aerogel surface, shape recovery performance (Video). AUTHOR INFORMATION Corresponding Author *E-mail: [email protected] Notes 22


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The authors declare no competing financial interest.

ACKNOWLEDGEMENTS This work was supported by the National Natural Science Foundation of China (No. 21776249, 21476195, and 21576236).

REFERENCES 1.

Shannon, M. A.; Bohn, P. W.; Elimelech, M.; Georgiadis, J. G.; Mariñas, B. J.; Mayes, A. M.,

Science and technology for water purification in the coming decades. Nature 2008, 452, 301-310. 2. Zhang, G.; Jiang, J.; Zhang, Q.; Zhan, X.; Chen, F., Amphiphilic poly(ether sulfone) membranes for oil/water separation: Effect of sequence structure of the modifier. AIChE J. 2017, 63, 739-750. 3. Peterson, C. H.; Rice, S. D.; Short, J. W.; Esler, D.; Bodkin, J. L.; Ballachey, B. E.; Irons, D. B., Long-Term Ecosystem Response to the Exxon Valdez Oil Spill. Science 2003, 302, 2082-2086. 4. Aksu, Z., Application of biosorption for the removal of organic pollutants: a review. Process Biochem. 2005, 40, 997-1026. 5. Agbovi, H. K.; Wilson, L. D., Design of amphoteric chitosan flocculants for phosphate and turbidity removal in wastewater. Carbohydr. Polym. 2018, 189, 360-370. 6. Jiang, J.; Zhang, Q.; Zhan, X.; Chen, F., A multifunctional gelatin-based aerogel with superior pollutants adsorption, oil/water separation and photocatalytic properties. Chem. Eng. J. 2019, 358, 15391551. 7. Wen, G.; Gao, X.; Guo, Z., Simple fabrication of a multifunctional inorganic paper with high efficiency separations for both liquids and particles. J. Mater. Chem. A 2018, 6, 21524-21531. 8. Kim, D. J.; Jo, W., Sustainable treatment of harmful dyeing industry pollutants using SrZnTiO3/gC3N4 heterostructure with a light source-dependent charge transfer mechanism. Appl. Catal., B 2019, 242, 171-177. 9. Jiang, J.; Zhang, Q.; Zhan, X.; Chen, F., Renewable, Biomass-Derived, Honeycomblike Aerogel As a Robust Oil Absorbent with Two-Way Reusability. ACS Sustainable Chem. Eng. 2017, 5, 1030710316. 10. Ge, J.; Zong, D.; Jin, Q.; Yu, J.; Ding, B., Biomimetic and Superwettable Nanofibrous Skins for Highly Efficient Separation of Oil-in-Water Emulsions. Adv. Funct. Mater. 2018, 28, 1705051. 11. Li, J.; Zhou, Y.; Luo, Z., Mussel-inspired V-shaped copolymer coating for intelligent oil/water separation. Chem. Eng. J. 2017, 322, 693-701. 12. Fu, Y.; Jin, B.; Zhang, Q.; Zhan, X.; Chen, F., pH-Induced Switchable Superwettability of Efficient Antibacterial Fabrics for Durable Selective Oil/Water Separation. ACS Appl. Mater. Interfaces 2017, 9, 30161-30170. 13. Broje, V.; Keller, A. A., Improved Mechanical Oil Spill Recovery Using an Optimized Geometry for the Skimmer Surface. Environ. Sci. Technol. 2006, 40, 7914-7918. 14. Kujawinski, E. B.; Kido Soule, M. C.; Valentine, D. L.; Boysen, A. K.; Longnecker, K.; Redmond, M. C., Fate of Dispersants Associated with the Deepwater Horizon Oil Spill. Environ. Sci. Technol. 2011, 23


Langmuir 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

45, 1298-1306. 15. Zhu, Z.; Wang, W.; Qi, D.; Luo, Y.; Liu, Y.; Xu, Y.; Cui, F.; Wang, C.; Chen, X., Calcinable Polymer Membrane with Revivability for Efficient Oily-Water Remediation. Adv. Mater. 2018, 30, 1801870. 16. Guan, H.; Cheng, Z.; Wang, X., Highly Compressible Wood Sponges with a Spring-like Lamellar Structure as Effective and Reusable Oil Absorbents. ACS Nano 2018, 12, 10365-10373. 17. Lv, Y.; Zhang, C.; He, A.; Yang, S.; Wu, G.; Darling, S. B.; Xu, Z., Photocatalytic Nanofiltration Membranes with Self-Cleaning Property for Wastewater Treatment. Adv. Funct. Mater. 2017, 27, 1700251. 18. Zhang, W.; Liu, N.; Xu, L.; Qu, R.; Chen, Y.; Zhang, Q.; Liu, Y.; Wei, Y.; Feng, L., PolymerDecorated Filter Material for Wastewater Treatment: In Situ Ultrafast Oil/Water Emulsion Separation and Azo Dye Adsorption. Langmuir 2018, 34, 13192-13202. 19. Li, J.; Zhou, Y.; Luo, Z., Polymeric materials with switchable superwettability for controllable oil/water separation: A comprehensive review. Prog. Polym. Sci. 2018, 87, 1-33. 20. Huang, J.; Yan, Z., Adsorption Mechanism of Oil by Resilient Graphene Aerogels from Oil–Water Emulsion. Langmuir 2018, 34, 1890-1898. 21. Lamy-Mendes, A.; Silva, R. F.; Durães, L., Advances in carbon nanostructure-silica aerogel composites: a review. J. Mater. Chem. A 2018, 6, 134-1369. 22. Fan, Y.; Ma, W.; Han, D.; Gan, S.; Dong, X.; Niu, L., Convenient Recycling of 3D AgX/Graphene Aerogels (X = Br, Cl) for Efficient Photocatalytic Degradation of Water Pollutants. Adv. Mater. 2015, 27, 3767-3773. 23. Wang, Y.; Feng, Y.; Yao, J., Construction of hydrophobic alginate-based foams induced by zirconium ions for oil and organic solvent cleanup. J. Colloid Interface Sci. 2019, 533, 182-189. 24. Hu, T.; Li, L.; Zhang, J., Green Synthesis of Ant Nest-Inspired Superelastic Silicone Aerogels. ACS Sustainable Chem. Eng. 2018, 6, 11222-11227. 25. Kontturi, E.; Laaksonen, P.; Linder, M. B.; Groschel, A. H.; Rojas, O. J.; Ikkala, O., Advanced materials through assembly of nanocelluloses. Adv. Mater. 2018, 30, 1703779. 26. Moon, R. J.; Martini, A.; Nairn, J.; Simonsen, J.; Youngblood, J., Cellulose nanomaterials review: structure, properties and nanocomposites. Chem Soc Rev 2011, 40, 3941-3994. 27. Zhang, X.; Feng, Y.; Huang, C.; Pan, Y.; Yao, J., Temperature-induced formation of cellulose nanofiber film with remarkably high gas separation performance. Cellulose 2017, 24, 5649-5656. 28. Klemm, D.; Kramer, F.; Moritz, S.; Lindström, T.; Ankerfors, M.; Gray, D.; Dorris, A., Nanocelluloses: a new family of nature-based materials. Angew. Chem. Int. Ed. 2011, 50, 5438-5466. 29. Lavoine, N.; Bergstr M, L.; Universitet, S.; Fakulteten, N.; MMK, I. F. R. M., Nanocellulose-based foams and aerogels: processing, properties, and applications. Journal of Materials Chemistry A 2017, 5, 1615-16117. 30. Wang, H.; Chen, Y.; Dang, B.; Shen, X.; Jin, C.; Sun, Q.; Pei, J., Ultrafine Mn ferrite by anchoring in a cellulose framework for efficient toxic ions capture and fast water/oil separation. Carbohydr. Polym. 2018, 196, 117-125. 31. Xiao, J.; Lv, W.; Song, Y.; Zheng, Q., Graphene/nanofiber aerogels: Performance regulation towards multiple applications in dye adsorption and oil/water separation. Chem. Eng. J. 2018, 338, 202210. 32. He, J.; Zhao, H.; Li, X.; Su, D.; Zhang, F.; Ji, H.; Liu, R., Superelastic and superhydrophobic bacterial cellulose/silica aerogels with hierarchical cellular structure for oil absorption and recovery. J. 24


Page 24 of 27

Page 25 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Langmuir

Hazard. Mater. 2018, 346, 199-207. 33. Gu, J.; Hu, C.; Zhang, W.; Dichiara, A. B., Reagentless preparation of shape memory cellulose nanofibril aerogels decorated with Pd nanoparticles and their application in dye discoloration. Appl. Catal., B 2018, 237, 482-490. 34. Zhang, H.; Li, Y.; Shi, R.; Chen, L.; Fan, M., A robust salt-tolerant superoleophobic chitosan/nanofibrillated cellulose aerogel for highly efficient oil/water separation. Carbohydr. Polym. 2018, 200, 611-615. 35. Luo, H.; Xie, J.; Wang, J.; Yao, F.; Yang, Z.; Wan, Y., Step-by-step self-assembly of 2D few-layer reduced graphene oxide into 3D architecture of bacterial cellulose for a robust, ultralight, and recyclable all-carbon absorbent. Carbon 2018, 139, 824-832. 36. Rafieian, F.; Hosseini, M.; Jonoobi, M.; Yu, Q., Development of hydrophobic nanocellulose-based aerogel via chemical vapor deposition for oil separation for water treatment. Cellulose 2018, 25, 46954710. 37. Septevani, A. A.; Evans, D. A. C.; Hosseinmardi, A.; Martin, D. J.; Simonsen, J.; Conley, J. F.; Annamalai, P. K., Atomic Layer Deposition of Metal Oxide on Nanocellulose for Enabling Microscopic Characterization of Polymer Nanocomposites. Small 2018, 14, 1803439. 38. Gao, R.; Xiao, S.; Gan, W.; Liu, Q.; Amer, H.; Rosenau, T.; Li, J.; Lu, Y., Mussel Adhesive-Inspired Design of Superhydrophobic Nanofibrillated Cellulose Aerogels for Oil/Water Separation. ACS Sustainable Chem. Eng. 2018, 6, 9047-9055. 39. Zhao, J.; Lu, Z.; He, X.; Zhang, X.; Li, Q.; Xia, T.; Zhang, W.; Lu, C.; Deng, Y., One-step fabrication of Fe(OH)3 @cellulose hollow nanofibers with superior capability for water purification. ACS Appl. Mater. Interfaces 2017, 9, 25339-25349. 40. Zhao, J.; Lu, Z.; He, X.; Zhang, X.; Li, Q.; Xia, T.; Zhang, W.; Lu, C., Fabrication and Characterization of Highly Porous Fe(OH)3@Cellulose Hybrid Fibers for Effective Removal of Congo Red from Contaminated Water. ACS Sustainable Chem. Eng. 2017, 5, 7723-7732. 41. Zhang, H.; Li, Y.; Lu, Z.; Chen, L.; Huang, L.; Fan, M., A robust superhydrophobic TiO2 NPs coated cellulose sponge for highly efficient oil-water separation. Sci Rep 2017, 7. 42. Jiao, Y.; Wan, C.; Bao, W.; Gao, H.; Liang, D.; Li, J., Facile hydrothermal synthesis of Fe3O4 @cellulose aerogel nanocomposite and its application in Fenton-like degradation of Rhodamine B. Carbohydr. Polym. 2018, 189, 371-378. 43. Xue, J.; Song, F.; Yin, X.; Zhang, Z.; Liu, Y.; Wang, X.; Wang, Y., Cellulose NanocrystalTemplated Synthesis of Mesoporous TiO2 with Dominantly Exposed (001) Facets for Efficient Catalysis. ACS Sustainable Chem. Eng. 2017, 5, 3721-3725. 44. Xu,

C.;

Feng,

R.;

Song,

F.;

Wang,

X.;

Wang,

Y.,

Desert

Beetle-Inspired

Superhydrophilic/Superhydrophobic Patterned Cellulose Film with Efficient Water Collection and Antibacterial Performance. ACS Sustainable Chem. Eng. 2018, 6, 14679-14684. 45. Wang, X.; Song, F.; Xue, J.; Qian, D.; Wang, X.; Wang, Y., Mechanically strong and tough hydrogels with excellent anti-fatigue, self-healing and reprocessing performance enabled by dynamic metal-coordination chemistry. Polymer 2018, 153, 637-642. 46. Iguchi, M.; Yamanaka, S.; Budhiono, A., Bacterial cellulose — a masterpiece of nature's arts. J. Mater. Sci. 2000, 35, 261-270. 47. Wu, Z.; Liang, H.; Chen, L.; Hu, B.; Yu, S., Bacterial cellulose: a robust platform for design of three dimensional carbon-based functional nanomaterials. Acc. Chem. Res. 2016, 49, 96-105. 48. Shao, Q.; Jiang, S., Molecular Understanding and Design of Zwitterionic Materials. Adv. Mater. 25


Langmuir 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

2015, 27, 15-26. 49. Mi, L.; Jiang, S., Integrated Antimicrobial and Nonfouling Zwitterionic Polymers. Angew. Chem. Int. Ed. 2014, 53, 1746-1754. 50. Zhang, G.; Gao, F.; Zhang, Q.; Zhan, X.; Chen, F., Enhanced oil-fouling resistance of poly(ether sulfone) membranes by incorporation of novel amphiphilic zwitterionic copolymers. RSC Adv. 2016, 6, 7532-7543. 51. Sai, H.; Xing, L.; Xiang, J.; Cui, L.; Jiao, J.; Zhao, C.; Li, Z.; Li, F., Flexible aerogels based on an interpenetrating network of bacterial cellulose and silica by a non-supercritical drying process. J. Mater. Chem. A 2013, 1, 7963-7970. 52. Xu, X.; Zhou, J.; Nagaraju, D. H.; Jiang, L.; Marinov, V. R.; Lubineau, G.; Alshareef, H. N.; Oh, M., Flexible, Highly Graphitized Carbon Aerogels Based on Bacterial Cellulose/Lignin: Catalyst-Free Synthesis and its Application in Energy Storage Devices. Adv. Funct. Mater. 2015, 25, 3193-3202. 53. Li, C.; Wu, Z.; Liang, H.; Chen, J.; Yu, S., Ultralight multifunctional carbon-based aerogels by combining graphene oxide and bacterial cellulose. Small 2017, 13, 1700453. 54. Si, Y.; Yu, J.; Tang, X.; Ge, J.; Ding, B., Ultralight nanofibre-assembled cellular aerogels with superelasticity and multifunctionality. Nat. Commun. 2014, 5, 1-9. 55. Xiong, Y.; Wang, C.; Wang, H.; Jin, C.; Sun, Q.; Xu, X., Endowing graphene with superior cation/anion co-purification and visible photocatalysis performances by in situ deposition of silver compounds. J. Mater. Chem. A 2017, 5, 20903-20910. 56. Artus, G. R. J.; Jung, S.; Zimmermann, J.; Gautschi, H. P.; Marquardt, K.; Seeger, S., Silicone Nanofilaments and Their Application as Superhydrophobic Coatings. Adv. Mater. 2006, 18, 2758-2762. 57. Zheng, Q.; Cai, Z.; Gong, S., Green synthesis of polyvinyl alcohol (PVA)–cellulose nanofibril (CNF) hybrid aerogels and their use as superabsorbents. J. Mater. Chem. A 2014, 2, 3110-3118. 58. Vasconcelos, N. F.; Feitosa, J. P. A.; Da Gama, F. M. P.; Morais, J. P. S.; Andrade, F. K.; de Souza Filho, M. D. S. M.; Rosa, M. D. F., Bacterial cellulose nanocrystals produced under different hydrolysis conditions: Properties and morphological features. Carbohydr. Polym. 2017, 155, 425-431. 59. Lu, Y.; Liu, H.; Gao, R.; Xiao, S.; Zhang, M.; Yin, Y.; Wang, S.; Li, J.; Yang, D., CoherentInterface-Assembled Ag2O-Anchored Nanofibrillated Cellulose Porous Aerogels for Radioactive Iodine Capture. ACS Appl. Mater. Interfaces 2016, 8, 29179-29185. 60. Zhou, W.; Liu, H.; Wang, J.; Liu, D.; Du, G.; Cui, J., Ag2O/TiO2 Nanobelts Heterostructure with Enhanced Ultraviolet and Visible Photocatalytic Activity. ACS Appl. Mater. Interfaces 2010, 2, 23852392. 61. Wang, X.; Li, S.; Yu, H.; Yu, J.; Liu, S., Ag2O as a New Visible-Light Photocatalyst: Self-Stability and High Photocatalytic Activity. Chem. Eur. J. 2011, 17, 7777-7780. 62. Tbessi, I.; Benito, M.; Llorca, J.; Molins, E.; Sayadi, S.; Najjar, W., Silver and manganese co-doped titanium oxide aerogel for effective diclofenac degradation under UV-A light irradiation. J. Alloys Compd. 2019, 779, 314-325. 63. Tan, L.; Yu, C.; Wang, M.; Zhang, S.; Sun, J.; Dong, S.; Sun, J., Synergistic effect of adsorption and photocatalysis of 3D g-C3N4-agar hybrid aerogels. Appl. Surf. Sci. 2019, 467-468, 286-292. 64. Ma, Y.; Wang, J.; Xu, S.; Feng, S.; Wang, J., Ag2O/sodium alginate-reduced graphene oxide aerogel beads for efficient visible light driven photocatalysis. Appl. Surf. Sci. 2018, 430, 155-164.

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Abstract Graphic

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Shape Recovery Zwitterionic Bacterial Cellulose Aerogels with

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