Cellulose Membrane Surface Research Articles

Long-Cycling Cellulose-Based Gel Polymer Electrolyte Utilizing Nanohydrotalcite as a Li+ Transport Redistributor.

The hydroxyl groups on the surface of the cellulose-based gel polymer electrolyte lead to poor interfacial compatibility due to side reactions with lithium sheets. In this paper, a novel cellulose-based gel polymer electrolyte was prepared by uniformly coating the surface of a cellulose membrane with a nanohydrotalcite/PVDF-HFP composite using electrospinning technology. This cellulose-based gel polymer electrolyte exhibits good interfacial compatibility and excellent cycling stability (91.7% specific capacity retention after 500 cycles at 0.5C). Theory and experiments have shown that nanohydrotalcite on the surface of cellulose membrane can effectively prevent the contact of hydroxyl groups with lithium sheets to reduce the side reactions. In addition, nanohydrotalcite can also act as a Li+ transport redistributor to facilitate the uniform deposition of Li+ and reduce the formation of lithium dendrites to extend the cycle life.

Enzyme colorimetric cellulose membrane bioactivity strips based on acetylcholinesterase immobilization for inhibitors preliminary screening

To quickly screen the active pharmaceutical ingredient that can be used as acetylcholinesterase inhibitors (AChEIs) to treat Alzheimer's disease, an enzyme colorimetric cellulose membrane bioactivity strip (CBS) was developed for simple and rapid screening of AChEIs. The amino group of acetylcholinesterase (AChE) undergoes Schiff base reaction with the aldehyde group on the oxidized cellulose membranes, then the AChE was covalently cross-linking on the surface of cellulose membranes, enabling the screening based on Ellman's enzyme colorimetric method. When the enzyme activity of AChE was inhibited after incubation with inhibitors, the hydrolysis of S-Acetylthiocholine iodide decreased, consequently, the 5-thio-2-nitrobenzoic acid generated by the reaction with 5,5′-dithiobis (2-nitrobenzoic acid) also decreased, leading to a decreased color intensity. In addition, CBSs had fast chromogenic time, excellent specificity, and extraordinary storage stability. Tacrine and Donepezil were used as representative inhibitors during the detection, while their IC50 and limit of detection were determined.Therefore, our work not only established a platform for effective preliminary screening of AChEIs but also inspired the further development of other cellulose membrane-based biosensors.

Effect of Homogenization Pressure on Bacterial Cellulose Membrane Characteristic Made from Pineapple Peel Waste

Many studies were conducted to maintain the environment by reducing the waste, especially pineapple peel waste. This study aims to explore the effect of various pressure of the homogenization process on bacterial cellulose membrane surface morphology and structure produced using extract of pineapple peel waste. The methods include the preparation of pellicle samples from the product of the fermentation process of Acetobacter xylinum using a medium from the extract of pineapple peel waste. Bacterial cellulose pellicles were crushed using a blender. Mashed bacterial cellulose pellicle then homogenized in High-Pressure Homogenizer with pressure variation of 0 bar, 150 bar, 300 bar, 450 bar, dan 600 bar then cast into a mold. The bacterial cellulose solutions were dried in an oven at 60°C for 8 hours. The dried bacterial cellulose membrane was analyzed using XRD for the structure and SEM analysis for the morphology. The results indicate that the crystalline properties of BCM were shifted after being treated by various pressure processing in a High-Pressure Homogenizer. It was found that the High-Pressure Homogenizer with higher pressure reduced the peak intensity, decreased crystalline index from 87% to 70%, and decreased the degree of crystalline from 88% to 77% without changing the cellulose structure. The higher pressure of the homogenization process causes the porosity of the membrane to be decreased.

Engineered Janus cellulose membrane with the asymmetric-pore structure for the superhigh-water flux desalination

Membranes are the dominant material for seawater desalination and clean-water harvesting, which are commonly composed of synthetic polymers, showing low hydrophilicity and environmental hazard. Herein, we developed a low-cost, intrinsically green, superhigh-water flux Janus cellulose membrane (CEM) via a facile cellulase etching strategy. Coating cellulase on the single surface of cellulose membrane (such as top surface), triggers effective etching on its top section rather than bottom section, which architects an asymmetric-pore structure of the Janus CEM including porous top-and dense bottom-layer. Such distinction endows the Janus CEM with an unprecedented high-water flux of 135.75 LMH and a low salt-water ratio of 0.29 g·L−1 for 1 M NaCl solution, which is 17-time higher and 62-time lower than that of the pristine CEM. Our Janus CEM enables a promising participant for the advanced membrane materials toward versatile separation engineering.

Further modification of oil–water separation membrane based on chitosan and titanium dioxide

In this paper, chitosan/nano-TiO2-modified liquid was coated on the surface of cellulose membrane by negative pressure suction filtration and a new method of preparing oil–water separation membrane was completed based on the pure nitrocellulose membrane. The performance parameters of cellulose composite membrane modified by chitosan and titanium dioxide with different concentration ratios were studied in terms of microstructure, element distribution and composition, wettability, using SEM, XPS, contact angle and other characterization methods. The optimal ratio of chitosan and titanium dioxide in the modified solution was selected to determine the optimal process parameters for the preparation of the new membrane. Because of the existence of nano-TiO2 particles in the new membrane, further study the effect of light on the membrane flux is required.

Facile preparation of superhydrophilic/underwater superoleophobic cellulose membrane with CaCO3 particles for oil/water separation

The oily wastewater has been widely concerned owing to growing industrial wastewater and marine pollution. Herein, a cellulose-based oil/water separation membrane was fabricated using a very simple alternating soaking process (ASP). First, the sodium alginate was coated on the cellulose membrane surface (filter paper), and then CaCO3 particles were assembled onto the membrane surface through ASP, finally we can get the superhydrophilic/underwater superoleophobic cellulose membrane (FP@SA/CaCO3) for oil/water separation. The underwater oil contact angle (OCA) of FP@SA/CaCO3 is 151.1°, which indicated that FP@SA/CaCO3 has good underwater superoleophobicity. Moreover, for different oil/water mixtures, the FP@SA/CaCO3 membrane has outstanding separation efficiency of over 99.2 % and the flux of over 400 L m−2 h−1. Besides, even after 20 reuse, FP@SA/CaCO3 still showed a high flux and separation efficiency, indicating FP@SA/CaCO3 has good reusability. The FP@SA/CaCO3 membrane with low cost and high performance shows a good application market for oily wastewater remediation in the future.

Multivariate optimization of field-flow fractionation of nanoscale synthetic amorphous silica in processed foods supported by computational modelling

Separation and size characterization of SiO2 in a laminar flow mode on the surface of cellulose membrane.

Challenges to Achieving Strong but Fully Degradable Adhesive Joints between Wet Cellulose Surfaces.

The dramatic loss of strength upon exposure to water is one of the challenges preventing the widespread substitution of plastic packaging with paper and paperboard. Although treatment with conventional wet strength resins and other adhesive polymers can strengthen wet paper, it is at the expense of green credentials, including easy recycling or rapid composting. The goal of this work was to demonstrate the adhesive requirements for strong, wet cellulose-cellulose joints that can be recycled easily because the joint strength can be destroyed by the presence of a weak reducing agent. Cellulose membrane surfaces were first treated with a bound layer of carboxymethyl cellulose, modified to have covalently tethered hydrazide groups. Joints were fabricated by laminating two hydrazide-modified membranes with a polymeric adhesive bearing aldehyde functionality. Aldehydes spontaneously condense with hydrazide to give hydrazone bonds. When the adhesive was oxidized dextran, the wet laminates had an intermediate strength. Upon exposure to a reducing agent, the joint strength was reduced to nearly zero because every hydrazone moiety connecting two cellulose surfaces included a cleavable disulfide linkage. By contrast, glyoxalated cationic polyacrylamide gave very strong wet joints. However, the wet adhesion was dominated by polyelectrolyte complexation, and the presence of hydrazone linkages had little influence on the wet adhesion. We conclude that robust joint degradability will require cleavable linkages in the adhesive backbone while minimizing polyelectrolyte complexation.

Procion Blue H-5R functionalized cellulose membrane with specific removal of bilirubin

The specific removal of bilirubin is essential to cure hyperbilirubinemia. In this study, cellulose membranes were prepared by a phase inversion technique with surface functionalized Procion Blue H-5R (PB) for bilirubin adsorption. The chemical structures and morphologies of membranes were characterized by FITR, XPS and SEM. The immobilized PB amounts of membranes were investigated. Moreover the effects of immobilized PB amounts, initial concentration of bilirubin, NaCl concentration, pH value, recycle numbers and BSA concentration on adsorption capability of PB-immobilized cellulose membrane to bilirubin. Results showed that PB was immobilized onto the cellulose membrane surfaces and reached a maximum amount of 230 mg/g membrane. The bilirubin adsorption isotherm fitted Langmuir model well. Furthermore, the PB-immobilized membrane could specifically adsorb bilirubin in BSA/bilirubin mixed solution and bilirubin adsorption capacity reached 26 mg/g at pH 9.5. The membrane showed excellent reusability that the adsorption capability of bilirubin decreased 1.3% after 3 adsorption–desorption cycles. This work indicated that the Procion Blue H-5R can be expected as a ligand for specific removal of bilirubin.

Synthesis of super hydrophilic cellulose-alpha zirconium phosphate ion exchange membrane via surface coating for the removal of heavy metals from wastewater

In this study, commercial cellulose membranes were surface coated with alpha‑zirconium phosphate nanoparticles (α-ZrP-n) to study their impact on the overall removal efficiency of heavy metals from synthetic metal mixture wastewater solution. A total of four homogeneous solutions (0.25, 0.50, 0.75, and 1.00 wt%) of α-ZrP-n were prepared by sonicating the nanoparticles in deionized water. These solutions were used to surface coat the commercial cellulose membranes. The Scanning Electron Microscopy (SEM) along with Energy Dispersive Spectroscopy (EDS) were used to confirm the attachment of α-ZrP-n on the cellulose membrane surface. Furthermore, the structural characteristics of the α-ZrP-n modified cellulose membranes were also studied. The water contact angle results showed that all coated membranes remained super-hydrophilic. The porosity of the membranes decreased to 48% with the addition of 1.00 wt% α-ZrP-n compared to 65% for the pristine membrane. The mechanical strength has improved from 3.4 MPa for the pristine membrane to about 4 MPa for the 1.00 wt% α-ZrP-n membrane. Similarly, the thermal stability was found to be slightly enhanced as evidenced by the increase in decomposition temperature to 280 and 285 °C in the 0.75 and 1.00 wt% α-ZrP-n membranes, respectively. Furthermore, a removal efficiency of 97.0 ± 0.6, 98.0 ± 0.5, 99.5 ± 0.2, and 91.5 ± 2.0% for Cu (II), Zn (II), Ni (II), and Pb (II), respectively, was observed with the 0.50 wt% α-ZrP-n membrane. This removal was achieved at a flux of 41.85 ± 0.87 × 103 LMH. Increasing the α-ZrP-n concentration further did not show any improvement in the overall removal efficiency. However, it led to 46% flux reduction in the 1.00 wt% α-ZrP-n membrane. The mechanism of removal of the heavy metal ions was postulated to be a combination of ion exchange and electrostatic attraction of the strong negatively charged α-ZrP-n membranes and the free metal ions in the wastewater solution.

Self-Assembly Stereo-Specific Synthesis of Silver Phosphate Microparticles on Bacterial Cellulose Membrane Surface For Antimicrobial Applications

In situ self-assembly stereo-specific synthesis of silver phosphate (AgP) microparticles (MPs) in one side bacterial cellulose (BC) membrane surface and loading of ciprofloxacin provides BC scaffolds with a broad-spectrum antimicrobial activity against Escherichia coli and Staphylococcus aureus. The BC membranes containing AgP-MPs can be loaded >5 times with ciprofloxacin compared to naked BC. The reuse of ciprofloxacin-loaded AgP-BC scaffolds in fresh cultures of both tested microbes showed high inhibition haloes without any signal of microbial resistance or scaffold activity decay after 30 days of assays. Additionally, microbial biofilms of E. coli and S. aureus were mostly killed by AgP-BC scaffolds loaded with ciprofloxacin in 1 h. The biophysical characterization of the hybrid AgP-BC scaffolds was performed by scanning electron microscopy (SEM), vibrational spectroscopy (FTIR), calorimetric techniques and X-ray diffraction (XRD). SEM images display AgP-MP spheroid structures with a high homogenous distribution on BC scaffold surfaces. The properties of the novel AgP-BC matrices are very promissory for biomedical applications, like a therapeutic dressing patches for the prevention and treatment of microbial infections in skin wounds and burns.

Universal and one-step visualization of latent fingermarks on various surfaces using hydrophilic cellulose membrane and dye aqueous solution

A high-resolution and universal method for the rapid visualization of latent fingermarks on a broad variety of surfaces has been achieved by simply combining hydrophilic cellulose membrane with dye aqueous solution. In this approach, the relatively hydrophobic characteristic of fingermark residue enable the deposit act as a “mask”, directing dye absorption processes to regions of both furrows without the ridge residues and bare cellulose membrane substrate. This effect during the spatially selective dye absorption generates a negative pattern of the fingermark within a few seconds to minutes depending on the properties of the substrates and fingermark types. It provides observation of latent fingermarks on cellulose membrane surface with high definition of level 2 and level 3 details used for personal identification purposes. It is also highly-efficient for visualizing the latent fingermarks lifted from various common (glass, carton, ceramic cup) and problematic (banknote, human skin and leather) surfaces by using transparent adhesive tape. To examine the generality of the proposed method, eight different kinds of dye aqueous solutions have been tested for developing latent fingermarks and they all provide very good results as expected. Moreover, this approach is easily used for aged fingermarks and natural fingermarks as well. Imaging may be accomplished visibly (by dye color) and topographically (using a microscope or a camera). This approach is a simple, rapid, non-destructive, safe, low-cost, universal and high resolution method compared with conventional approaches, so it demonstrates good potentiality in individual identity validation related applications.

Enhancement of fibroblast growing on the mannosylated surface of cellulose membranes

Bacterial cellulose membrane is a biomaterial with high value in the biomedical field. Many groups have been making efforts to promote chemical modifications of its structure and, consequently, add new characteristics. Recently, our group has developed a methodology to insert monoester succinic acid in bacterial cellulose membrane without disrupting the microfibril network and bind a protein on it. Considering the role of carbohydrates in the molecular recognition process in biological events, we continued these studies by inserting covalently multiples copies of aryl monosaccharide to bacterial cellulose succinylated and to study the in vitro tissue compatibility using fibroblasts. The mix of synthetical chemistry and material modification was performed to prepare aminoaryl mannoside and conjugate it, via amide bond using ultrasonic irradiation, to succinic group of bacterial cellulose. This material was characterized chemically (IR, UV–vis, 13C NMR CP-MAS) and physically (TGA and AFM). Mannosylated cellulose showed good in vitro compatibility with fibroblasts demonstrating its potential in the tissue engineering field which could provide a tissue compatible scaffold.

Enhanced starch hydrolysis using α-amylase immobilized on cellulose ultrafiltration affinity membrane

In order to prepare ultrafiltration membranes possessing biocatalytic properties, α-amylase has been immobilized on cellulose membranes. Enzyme immobilization was based on a covalent bonding between chitosan and a surface of cellulose membrane, followed by an attachment of Cibacron Blue F3G-A dye as affinity ligand. Various factors affecting the immobilization process, such as enzyme concentration, pH of modifying solution, zeta-potential of membrane surface, and stability of immobilized enzyme were studied. The applicability of immobilized α-amylase has been investigated in ultrafiltration processes. The immobilization of α-amylase on membrane surface allows to increase the value of mass transfer coefficient and to decrease the concentration polarization effect during ultrafiltration of starch solutions. The enzyme layer on the membrane surface prevents a rapid increase of starch concentration due to the amylase hydrolysis of starch in the boundary layer. The presented affinity immobilization technique allows also for the regeneration of membranes from inactivated enzyme.

Choline phosphate functionalized cellulose membrane: A potential hemostatic dressing based on a unique bioadhesion mechanism

Wound dressings are a key component in provision of optimal conditions for bleeding control and wound healing. For absorbent dressings, electrostatic interactions are frequently utilized as one of the mechanisms driving dressing adhesion. Herein, a choline phosphate functionalized biocompatible cellulose membrane that can efficiently arrest human red blood cells was developed to have potential application in wound dressing. The bioadhesion is based on the unique multivalent electrostatic interaction between the head groups of phosphatidyl choline based lipids on the cell membrane and its inverse orientation but virtually identical structure, choline phosphate, coupled to the cellulose membrane. For functionalization, the cellulose membrane was decorated with polymer brushes bearing multiple choline phosphate groups via surface-initiator atom transfer radical polymerization followed by click chemistry. The modified cellulose membranes were characterized by ATR-FTIR and the molecular weight and the grafting density of polymer brushes grafted from the cellulose membrane surface were thoroughly evaluated by calibrated force-distance measurements with atomic force microscopy (AFM). This new method provides an approach to estimating polymer brush parameters on rough surfaces of unknown surface area based on the dependence of brush thickness on brush density and polymer molecular weight for a calibration set of brushes. The dependence of binding of human red blood cells (RBCs) to the cellulose membrane surface on the number density of choline phosphate groups (e.g. molecular weight) and the grafting density were investigated using this AFM-based approach. Bound RBCs showed “pseudopodia”-like membrane projections under scanning electron microscopy where cells contacted the microfibers of the cellulose, distorting the RBC shape, reflecting the multivalent interactions between the RBCs and the choline phosphate-doped cellulose membrane. We believe this efficient strategy provides a promising approach to blood conservation and trauma management. Statement of SignificanceUncontrolled bleeding can dramatically affect morbidity and mortality. Absorptive wound dressings provide either adherent or non-adherent layers to control bleeding. Our new adherent material is based on a universal adhesion reaction between cell membrane phosphatidyl choline (PC) headgroups and cellulose membranes (CM) decorated with polymer brushes carrying a CP group per monomer. The CP-PC multivalent interactions provide adherence to cut tissue margins and blood cells, blocking bleeding. We here demonstrate the strong specific binding of red cells to CM-CP but not CM-PC membranes and determine the requisite brush molecular weight and surface concentration via a new approach using atomic force microscopy, applicable to rough surfaces. We believe this strategy provides a promising approach to blood conservation and trauma management.

Immobilization of Papain with Ionic Liquids-regenerated Cellulose Membrane for Wool Fabric Modification†

Ionic liquid( IL) 1-butyl-3-methylimidazolium chloride( [Bmim]Cl) was used to dissolve microcrystalline cellulose Avicel to make IL-regenerated cellulose membrane for papain immobilization through silane modification method. It demonstrated that the immobilized papain could be obtained at the condition of6. 5%( mass fraction) Avicel /[BMIM]Cl for membrane as the solid support; 30% NH_2( CH_2)_3Si( OC_2H_5)_3at 50 ℃ to functionalize the carrier; adsorbing for 3 h followed by cross-linking for 4 h at 50 ℃,p H = 7. 0 and enzyme concentration of 300 mg/m L,using 10%( volume fraction) glutaraldehyde as the cross-linker. After immobilization,papain was immobilized to the both sides of the regenerated cellulose membrane surfaces with high loading density. The immobilized papain could be limited on the wool fiber surface,only digesting the scale structure instead of native papain penetrating inside the fiber and generating the significant weight and strengthen loss.

On-line electrodialytic matrix isolation for chromatographic determination of organic acids in wine

Chromatographic determination of organic acids is widely performed, but the matrix often calls for lengthy and elaborate sample preparation prior to actual analysis. Matrix components, e.g., proteins, non-ionics, lipids etc. are typically removed by a combination of centrifugation/filtration and solid phase extraction (SPE) that may include the use of ion-exchange media. Here we report the quantitative electrodialytic transfer of organic acids from complex samples to ultrapure water in seconds using cellulose membranes modified with N,N-dimethylaminoethyl methacrylate, which essentially eliminates the negative ζ-potential of a regenerated cellulose membrane surface. The transfer characteristics of the ion transfer device (ITD) were evaluated with linear carboxylic acids. While the ion transfer efficiencies may be affected by the acid dissociation constants, in most cases it is possible to achieve quantitative transfer under optimized device residence time (solution flow rate) and the applied voltage. In addition, the transfer efficiency was unaffected by the wide natural variation of pH represented in real samples. The approach was applied to organic acids in various samples, including red wine, considered to represent an especially difficult matrix. While quantitative transfer of the organic acids (as judged by agreement with standard pretreatment procedures involving SPE) was achieved, transfer of other matrix components was <5%. The processed samples could then be chromatographically analyzed in a straightforward manner. We used ion exclusion chromatography with direct UV detection; in treated samples; there was a dramatic reduction of the large early peaks observed compared to only 0.45μm membrane filtered samples.

In vivo and in vitro evaluation of an Acetobacter xylinum synthesized microbial cellulose membrane intended for guided tissue repair.

BackgroundBarrier materials as cellulose membranes are used for guided tissue repair. However, it is essential that the surrounding tissues accept the device. The present study histologically evaluated tissue reaction to a microbial cellulose membrane after subcutaneous implantation in mice. Furthermore, the interaction between mesenchymal stem cells and the biomaterial was studied in vitro to evaluate its ability to act as cellular scaffold for tissue engineering.MethodsTwenty-five Swiss Albino mice were used. A 10 × 10 mm cellulose membrane obtained through biosynthesis using Acetobacter xylinum bacteria was implanted into the lumbar subcutaneous tissue of each mouse. The mice were euthanatized at seven, 15, 30, 60, and 90 days, and the membrane and surrounding tissues were collected and examined by histology.ResultsA mild inflammatory response without foreign body reaction was observed until 30 days post-surgery around the implanted membrane. Polarized microscopy revealed that the membrane remained intact at all evaluation points. Scanning electron microscopy of the cellulose membrane surface showed absence of pores. The in vitro evaluation of the interaction between cells and biomaterial was performed through viability staining analysis of the cells over the biomaterial, which showed that 95% of the mesenchymal stem cells aggregating to the cellulose membrane were alive and that 5% were necrotic. Scanning electron microscopy showed mesenchymal stem cells with normal morphology and attached to the cellulose membrane surface.ConclusionThe microbial cellulose membrane evaluated was found to be nonresorbable, induced a mild inflammatory response and may prove useful as a scaffold for mesenchymal stem cells.

Improvement of blood compatibility on cellulose membrane surface by grafting betaines

Cellulose is widely used as hemodialysis biomaterials due to their good permeability of water and solutes and mechanical strength. Nevertheless, their blood compatibility is still not adequate for blood purification. Surface modification is an effective way to improve the blood compatibility and remain the bulk properties of biomaterials. The purpose of this study was to design and synthesize a novel nonthrombogenic biomaterial by modifying the surface of cellulose with zwitterionic monomer. In this study, betaines (carboxybetaine and sulfobetaine) were grafted onto cellulose membrane respectively by a three-step procedure. In the first step, the membrane was treated with hexamethylene diisocyanate in toluene at 50 °C in the presence of di- n-butyltin dilaurate as a catalyst. The extent of the reaction was measured by ATR-IR spectra; a maximum number of free NCO group was obtained after a reaction time of 2.5 h. In the second step, the hydroxyl groups of N, N-dimethylethylethanolamine (DMEA) or 4-dimethylamino-1-butanol (DMAB) were allowed to react in toluene with isocyanate groups bound on surface. In the third step, betaines were formed on the surface through the ring-opening reaction between tertiary amine of DMEA or DMAB with 1,3-propanesultone (PS) or β-propiolactone (PL). It was characterized by ATR-IR and XPS that the grafted surfaces were composed sulfobetaine or carboxybetaine. The platelet adhesion test showed that membranes-grafted betaines have excellent blood compatibility feature by the low platelet adhesion.

Adsorption of Binary Liquid Crystals onto Cellulose Membrane for Thermo-Responsive Drug Delivery

A thermo-responsive membrane was developed by adsorbing the binary liquid crystals (LC) onto the cellulose nitrate membrane. The binary LC mixture is consisted of 36% cholesteric oleyl carbonate (COC) and 64% cholesteryl nonanoate (CN). The physico-chemical and the thermo-responsive properties of this binary LC adsorbed-membrane were examined. The results indicate that the adsorption behavior of binary LC mixture on the cellulose membrane was quick and reached to the equilibrium about 10 min, and linearly correlated with the increase of LC concentration used. The hydrophilic membrane was hydrophobicized after adsorption of binary LC mixture. The focal conic fan textures of binary LC mixture were observed from the surface of cellulose membrane. Due to the obedience and reproducibility of the binary LC used, the binary LC mixture-adsorbed membrane continuously exhibited an on-off thermo-responsive sensitivity to control the drug penetration.