Enhanced Dye Adsorption and Bacterial Removal of Magnetic Nanoparticle-Functionalized Bacterial Cellulose Acetate Membranes

Utilizing biomass waste as a potential resource for cellulose production holds promise in mitigating environmental consequences.The current study aims to utilize pineapple biowaste extract in producing bacterial cellulose acetate-based membranes with magnetic nanoparticles(Fe_(3)O_(4)nanoparticles)through the fermentation and esterification process and explore its characteristics.The bacterial cellulose fibrillation used a high-pressure homogenization procedure,and membranes were developed incorporating 0.25,0.50,0.75,and 1.0 wt.%of Fe3O4 nanoparticles as magnetic nanoparticle for functionalization.The membrane characteristics were measured in terms of Scanning Electron Microscope,X-ray diffraction,Fourier Transform Infrared,Vibrating Sample Magnetometer,antibacterial activity,bacterial adhesion and dye adsorption studies.The results indicated that the surface morphology of membrane changes where the bacterial cellulose acetate surface looks rougher.The crystallinity index of membrane increased from 54.34%to 68.33%,and the functional groups analysis revealed that multiple peak shifts indicated alterations in membrane functional groups.Moreover,adding Fe_(3)O_(4)-NPs into membrane exhibits paramagnetic behavior,increases tensile strength to 73%,enhances activity against E.coli and S.aureus,and is successful in removing bacteria from wastewater of the river to 67.4%and increases adsorption for anionic dyes like Congo Red and Acid Orange.

Preparation of Cellulose Acetate Butyrate Porous Micro/Nanofibrous Membranes and Their Properties

Cellulose acetate butyrate(CAB)is a cellulose ester that is commonly used in applications such as coatings and leather brighteners.However,its appearance in a fibrous form is rarely reported.CAB porous micro/nanofibrous membranes with a large number of nanopores on the fiber surface were successfully prepared by electrospinning with dichloromethane(DCM)/acetone(AC)as the mixed solvent.Apparent morphology,porosity,moisture permeability,air permeability,static water contact angles,and thermal conductivity of the fibrous membranes were investigated at different spinning voltages.The results showed that with the increase of the spinning voltage,the average fiber diameter of the CAB porous micro/nanofibrous membranes gradually decreased and the fiber diameter distribution was more uniform.When the spinning voltage reached 40 kV,the porosity reached 91.38%,the moisture permeability was up to 7430 g/(m^(2)·d),the air permeability was up to 36.289 mm/s,the static water contact angle was up to 145.0°,while the thermal conductivity of the fibrous membranes reached 0.030 W/(m·K).The material can be applied as thermal-insulation,waterproof and moisture-permeable membranes.

Nano-alumina@cellulose-coated separators with the reinforcedconcrete-like structure for high-safety lithium-ion batteries

Separators play a critical role in the safety and performance of lithium-ion batteries.However,commercial polyolefin separators are limited by their poor affinity with electrolytes and low melting points.In this work,we constructed a reinforced-concrete-like structure by homogeneously dispersing nano-Al_(2)O_(3) and cellulose on the separators to improve their stability and performance.In this reinforcedconcrete-like structure,the cellulose is a reinforcing mesh,and the nano-Al_(2)O_(3) acts as concrete to support the separator.After constructing the reinforced-concrete-like structure,the separators exhibit good stability even at 200℃(thermal shrinkage of 0.3%),enhanced tensile strain(tensile stress of 133.4 MPa and tensile strains of 62%),and better electrolyte wettability(a contact angle of 6.5°).Combining these advantages,the cells with nano-Al_(2)O_(3)@cellulose-coated separators exhibit stable cycling performance and good rate performance.Therefore,the construction of the reinforced-concretelike structure is a promising technology to promote the application of lithium-ion batteries in extreme environments.

ZIF-67@Cellulose nanofiber hybrid membrane with controlled porosity for use as Li-ion battery separator

Zeolitic imidazolate framework-67(ZIF-67) was synthesized on the surface of cellulose nanofibers(CNFs)in methonal to address the problems of unhomogeneous pore size and pore distribution of pure CNF membrane.A combination of Energy Dispersive X-Ray Spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS) and X-ray powder diffraction(XRD) patterns were used to determine the successful synthesis of ZIF-67@CNFs.The size of the ZIF-67 particles and pore size of the ZIF-67@CNF membrane were50-200 nm and 150-350 nm, respectively.The prepared ZIF-67@CNF membrane exhibited excellent thermal stability,lower thermal shrinkage and high surface wettability.The discharge capacity retention of the Li-ion batteries(LIBs) made with ZIF-67@CNF,glass fiber(GF),CNF and commercial polymer membranes after 100 th cycle at 0.5 C rate were 88.41%,86.22%,83.27%,and 81.03%,respectively.LIBs with ZIF-67@CNF membrane exhibited a better rate capability than these with other membranes.No damage of porous structure or peel-off of ZIF-67 was observed in the SEM images of ZIF-67@CNF membrane after100 th cycle.The improved cycling performance,rate capability,and good electrochemical stability implied that ZIF-67@CNFs membrane can be considered as a good alternative LIB separator.

Preparation and Characterization of Waterborne Polyurethane/Cellulose Nanocrystal Composite Membrane from Recycling Waste Paper

Cellulose plays a key role in abundant organic natural materials meeting the increasing demand for green and biocompatible products.The highly crystalline nanoscale component of cellulose nanocrystals has recently attracted great attention due to the versatile performance as filler or matrix in producing functional materials.In this work,we prepared the waterborne polyurethane via a prepolymer process,and obtained cellulose and cellulose nanocrystals from waste paper via a facile acid hydrolysis process.After that,the cellulose nanocrystals were assembled into film and mixed with polyurethane to prepare flexible polyurethane/cellulose nanocrystals composite membrane with different soaking time.The correlation between the bulk structure and applied properties including thermal resistance and mechanical property was investigated by using Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),thermogravimetric analysis(TGA),differential scanning calorimetry(DSC)and folding test.The structure analysis indicates that cellulose nanocrystals prepared from used paper have a quality similar to that of commercial cellulose.Meanwhile,the cellulose nanocrystals have been mixed with polyurethane uniformly.Polyurethane can significantly benefit to the thermal resistance and mechanical property of the cellulose nanocrystals film.The polyurethane/cellulose nanocrystals composite membrane present good flexibility and may hold a significantly potential application as visual and flexible material.

CELLULOSE MEMBRANE USED AS STATIONARY PHASE OF MEMBRANE AFFINITY CHROMATOGRAPHY

Cellulose membrane was used as Stahonary phase Of affinity chromeqraphy. A ￣ for theprepeboon Of microPOre cellulose membone born cellulose balm is describ6d. Terne dyeS,Cibacron BIne F3GA and cave Red KZBP were immobilbe as amnty figeds. UP tO IO0 mgCibacron BIne F3G^ can be coupled ontO 1 g merebrane mainx. A membene cadridge cocainingblue affinty membranes was also Prepared. The flux of the cadridge was much superior to that Ofcolumn PaCked ed agarose as sepadsn odium. On this cable, the Chromatography ofhuman seam albumin was performed.

Preparation of High Quality Indium Tin Oxide Film on a Microbial Cellulose Membrane Using Radio Frequency Magnetron Sputtering

Microbial cellulose （MC） membranes produced by Acetobacter xylinum NUST4.1,were used as flexible substrates for the fabrication of transparent indium tin oxide （ITO） electrodes.Transparent and conductive ITO thin films were deposited on MC membrane at room temperature using radio frequency （RF） magnetron sputtering.The optimum ITO deposition conditions were achieved by examining crystalline structure,surface morphology and op-toelectrical characteristics with X-ray diffraction （XRD）,scanning electron microscopy （SEM）,atomic force mi-croscopy （AFM）,and UV spectroscopy.The sheet resistance of the samples was measured with a four-point probe and the resistivity of the film was calculated.The results reveal that the preferred orientation of the deposited ITO crystals is strongly dependent upon with oxygen content （O2/Ar,volume ratio） in the sputtering chamber.And the ITO crystalline structure directly determines the conductivity of ITO-deposited films.High conductive [sheet resis-tance ～120 Ω·square-1 （Ω·sq-1）] and transparent （above 76%） ITO thin films （240 nm thick） were obtained with a moderate sputtering power （about 60 W） and with an oxygen flow rate of 0.25 ml·min-1 （sccm） during the deposi-tion.These results show that the ITO-MC electrodes can find their potential application in optoelectrical devices.

Concentration of Bio-Ethanol through Cellulose Ester Membranes during Temperature-Difference Controlled Evapomeation

To evaluate the high-performance of membrane materials in the concentration of an aqueous solution of dilute bioethanol under temperature-difference controlled evapomeation (TDEV), asymmetric porous cellulose nitrate (CN) and cellulose acetate (CA) membranes were prepared by a phase inversion method. In the concentration of dilute ethanol under TDEV, these membranes showed a high permeation rate and high ethanol/water selectivity. In membranes with almost the similar pore size, the ethanol/water selectivity was considerably higher for the CN membrane than the corresponding CA membrane. This result suggested that the affinity between the membrane material and the permeant is an important factor in the separation selectivity.

CHARACTERIZATION OF REGENERATED CELLULOSE MEMBRANES HYDROLYZED FROM CELLULOSE ACETATE

A series of cellulose acetate membranes were prepared by using formamide as additive, and then were hydrolyzed in 4 wt% aqueous NaOH solution for 8 h to obtain regenerated cellulose membranes. The dependence of degree of substitution, structure, porous properties, solubility and thermal stability on hydrolysis time was studied by chemical titration, Fourier transform infrared spectroscopy, scanning electron microscopy, wide-angle X-ray diffraction, and differential scanning calorimetry, respectively. The results indicated that the pore size of the regenerated cellulose membranes was slightly smaller than that of cellulose acetate membrane, while solvent-resistance, crystallinity and thermostability were significantly improved. This work provides a simple way to prepare the porous cellulose membranes, which not only kept the good pore characteristics of cellulose acetate membranes, but also possessed solvent-resistance, high crystallinity and thermostability. Therefore, the application range of cellulose acetate membranes can be expanded.

Immobilization of Glucose Oxidase on Cellulose/Cellulose Acetate Membrane and its Detection by Scanning Electrochemical Microscope (SECM)

s: Cellulose/cellulose acetate membranes were prepared and functionalized by introducing amino group on it, and then immobilized the glucose oxidase (Gox) on the functionalizd membrane. SECM was applied for the detection of enzyme activity immobilized on the membrane. Immobilized biomolecules on such membranes was combined with analysis apparatus and can be used in bioassays.

Evaluation of Several Procedures for Immobilizing Cholesterol Oxidase Based on Cellulose Acetate Membrane

Immobilized cholesterol oxidase (COD) membrane with higher catalytic activity is important for biosensor. In this paper, several procedures for immobilizing COD based on cellulose acetate (CA) membrane are studied. Reasons causing different catalytic activities are also discussed.

Application and Characterization of Cellulose Acetate Membrane Produced from Herbaceous Plant: Solidago Canadensis L.

In this work,the viability of Solidago Canadensis L. for cellulose acetate membrane production was tested. The cellulose was extracted from Solidago Canadensis L. stem by organic solvents,and the cellulose diacetate was obtained by acetylization of cellulose. The properties of the intermediate products of cellulose pulp and cellulose diacetate were characterized by FT-IR and XRD. Compared with commercial cellulose diacetate,the properties of cellulose diacetate were similar to those of the commercial cellulose diacetate. The cellulose acetate membrane with desirable pure water flux and rejection rate was obtained from cellulose diacetate by solution casting. The membrane showed favorable hydrophilic property so that it had good anti-pollution performance. The maximum pure water flux of the membrane was 27. 21 m L /( cm2· h) and the maximum rejection rate was 80. 39%. The results demonstrated that the membrane obtained from herbaceous plant: Solidago Canadensis L. had good performance of ultrafiltration.

Fabrication of Solvent-Resistant Nanofiltration Membrane via Interfacial Polymerization Based on Cellulose Acetate Membrane

Although a great progress has been achieved for the development of NF membranes and technologies and SRNF do show a great potential in the separation of organic components, an NF membrane with good separation performance and good resistance to organic solvents are urgently needed for a more complicated situation in practical. In this study, a kind of solvent-resistant nanofiltration (SRNF) membrane was fabricated via interfacial polymerization on a laboratory optimized cellulose acetate (CA) basic membrane. The effects of interfacial polymerization parameters, such as water phase concentration, immersed time in the water phase and in the organic phase, on the pure water flux and rejection rate of C-2R yellow dyestuffs were investigated. A highest dye rejection rate of 72.9% could be obtained by water phase solution containing 1% m-xylylenediamine (mXDA) and organic phase solution with 0.2% trimesoyl chloride (TMC) under immersed time in water phase of 6 minutes and in organic phase of 40 seconds. This membrane demonstrated better resistance to methyl alcohol compared to commercial membrane. This study may offer an avenue to develop a solvent-resistant nanofiltration membrane.

TEMPERATURE DEPENDENCE OF AIR SEPARATION OF LIQUID CRYSTALLINE TRIHEPTYL CELLULOSE/ETHYL CELLULOSE MEMBRANES

Triheptyl cellulose/ethyl cellulose(3/97)binary blend membranes were prepared from tetrahydrofuran,chloroform and dichloromethane solutions and their air separation capabit- ities were studied at different temperatures.With increasing temperature from 25 to 85℃,the flux QOEA of O_2-enriched air(OEA),O_2 permselectivity and the O_2 concentration Yo_2 in the OEA all increase.The membranes show a unique trend in their Yo_2～QOEA relationship,that is,the air separation capability increases simultaneously with the OEA permeation capability.The magnitudes of QOEA and Yo_2 for 17μm-thick membrane after the testg time of 36hours at 70℃ are 5×10^(-4)cm^3 (STP)/s·cm^2 and 37.6%,respectively.The air separation capability depends slightly on membrane forming solvents.

Cellulose Acetate Reverse Osmosis Membranes for Desalination:A Short Review

Freshwater scarcity is a critical challenge that human society has to face in the 21st century.Desalination of seawater by reverse osmosis(RO)membranes was regarded as the most promising technology to overcome the challenge given that plenty of potential fresh water resources in oceans.However,the requirements for high desalination efficiency in terms of permeation flux and rejection rate become the bottle-neck which needs to be broken down by developing novel RO membranes with new structure and composition.Cellulose acetate RO membranes exhibited long durability,chlorine resistance,and outstanding desalination efficiency that are worthy of being recalled to address the current shortcomings brought by polyamide RO membranes.In terms of performance enhancement,it is also important to use new ideas and to develop new strategies to modify cellulose acetate RO membranes in response to those complex challenges.Therefore,we focused on the state of the art cellulose acetate RO membranes and discussed the strategies on membrane structural manipulation adjusted by either phase separation or additives,which offered anti-fouling,anti-bacterial,anti-chlorine,durability,and thermo-mechanical properties to the modified membranes associated with the desalination performance,i.e.,permeation flux and rejection rate.The relationship between membrane structure and desalination efficiency was investigated and established to guide the development of cellulose acetate RO membranes for desalination.

Preparation and Characterization of Sulfated Cellulose Nanocrystalline and its Composite Membrane for Removal of Tetracycline Hydrochloride in Water

The removal of antibiotic pollutants remaining in the environmental media has been a big challenge nowadays.Herein,we report a facile and green approach to fabricate an eco-friendly composite membrane without addition of any toxic polymers or chemical cross-linking agents to effectively remove the tetracycline hydrochloride in Water.Firstly,the sulfated cellulose nanocrystalline(CNC) was obtained via hydrolysis of sulfuric acid by using microcrystalline cellulose(MCC) as raw material under ultrasonic condition.The as-prepared CNC has a nanowhisker dimension with 200.2 ± 110.2 nm in length,15.7 ± 9.3 nm in width,and 7.2 ± 3.1 nm in height.The obtained CNC is cellulose type I as determined by X-ray diffraction(XRD),while its crystallinity index(Crl) can reach 82.3%.Then,the composite membrane derived from the obtained CNC and commercial mixed cellulose ester(MCE)membrane was facilely prepared through vacuum dewatering process,which is applied to remove tetracycline hydrochloride(Th) in solution.The results showed that the removal efficiency of Th through the neat MCE was only28 ± 4%,while it could be improved to 58 ± 5% and 89 11%,respectively,by filtering through composite membranes with different contents of CNC deposition.Such effect is derived from the combine factors based on both steric hindrance(sieving) and electrostatic interaction(Donnan) effect of the composite membranes.The development of related CNC materials and composite fabrication processes is in favor of cost-effective and "green"polymer composites for the remediation of increasing antibiotic pollution and the purification of contaminated water nowadays.

Ion-conducting Membranes Based on Bacterial Cellulose Nanofibers Modified by Poly(sodium acrylate-co-2-acrylamido-2-methylpropanesulfonic acid)

Green method for preparation of ion-conducting membranes(ICM) based on bacterial cellulose nanofibers(CNF) modified by a copolymer of sodium acrylate and 2-acrylamido-2-methylpropanesulfonic acid was elaborated. FTIR and NMR data confirmed grafting of polyacrylate onto cellulose surface. Formation of porous structure of the ICM was controlled by SEM and AFM. The maximal ionic conductivity of the membranes reaches 1.5 and 3.1 mS·cm^(-1)(60 ℃ and 98% relative humidity) when they are saturated with water or H_2SO_4(1 mol·L^(-1)) electrolyte,respectively. Prepared ICM was tested as a separator in a symmetrical supercapacitor with electrodes based on polyaniline hydrogel. The assembled cell demonstrate ability to operate at high current density up to 100 A·g^(-1) maintaining specific capacitance 165 F·g^(-1). Maximal specific capacitance of 289 F·g^(-1) was achieved at current density 1 A·g^(-1). Retaining of 90% of initial capacitance after 10000 of charge-discharge cycles proves high electrochemical stability of prepared ICM.

Fabrication and Characterization of Pulp/Chitosan Composite Membranes Crosslinked with 3-Methylglutaric Anhydride for Pervaporation of Ethanol/Water Mixture

Chitosan/Cellulose (CTS/CL) composite membranes were prepared by cross-linking reaction with 3-methy- lglutaric anhydride (3MGA). The cross-linked membranes with CTS/CL were obtained at different CTS con- tents in variations from 50 to 100 wt%, and these membranes were applied in the dehydration of ethanol/wa- ter mixtures. Especially, it was observed that in the case of a composite membrane containing chitosan 80% (CTS/CL-80/20) showed a performance with a separation factor of α = 17.1 and a total permeation flux of J = 326 g/(m2h). It was observed that the total permeation flux decreased when the cross-linking increased and the increase in the ethanol content in the feed solution showed an increase in the separation factor. The CTS/ CL-80/20 showed excellent performance with good mechanical strength and dehydration performance in the ethanol/water mixture separation.

Efficiency of Advanced Membrane Wastewater Treatment Plant towards Removal of Aspirin, Salicylic Acid, Paracetamol and p-Aminophenol

The efficiency of membrane separation technology for wastewater treatment was employed to check its efficiency in removing pharmaceuticals, their degradation products and their metabolites from wastewater. Aspirin and paracetamol were found to degrade in wastewater furnishing salicylic acid and p-aminophenol, respectively. The kinetics for the degradation reactions of both drugs were investigated in wastewater environment and both have shown first order kinetics with rate constants 0.845 × 10^-8 Ms^-1 and 1.0 × 10^-8 Ms^-1 at room temperature, respectively. These values are an order of magnitude larger than those obtained in pure water under the same conditions. The over all performance of the plant has shown complete removal of these compounds from spiked wastewater within the detection limit of the analytical method. The most effective components for removing those drugs within the plant were activated carbon and clay micelle filters. The adsorption isotherms for these compounds have been studied using both activated carbon and newly developed adsober named clay-micelle complex. All studied isotherms were found to fit Langmuir isotherm. The Langmuir constant and the adsorption capacity were evaluated and discussed.

Efficient Facilitated Transport of Lead and Cadmium Across a Plasticized Triacetate Membrane Mediated by D2EHPA and TOPO

Cellulose triacetate membranes doped with organo-phosphoric carriers (2-ethylhexyl) phosphoric acid noted (D2EHPA) or trioctyl phosphine oxide noted (TOPO) as fixed carriers and 2-nitro phenyl octyl ether noted (NPOE) or tris ethylhexyl phosphate noted (TEHP) as a plasticizers have been prepared and applied for investigation to the facilitated transport of Pb(II) and Cd(II) ions from aqueous nitrate source phase. The membranes Polymer-Plasticizer- Carrier were characterised using chemical techniques as well as Fourier Transform Infra-Red (FTIR), X-ray Diffraction and Scanning electron microscopy (SEM). A study of the transport across a polymer inclusion membrane has shown that the lead or cadmium transport efficiency was increased using D2EHPA as carrier at pH 1-2.