Cellulose Membrane Research Articles

Effect of sampling face velocity on the ultrafine particle surface collection efficiency of a cellulose membrane filter and a cellulose-glass fiber filter for environmental airborne radioactivity monitoring.

Surface collection efficiency (SCE) of a cellulose membrane filter (CMF) and a cellulose-glass fiber filter used in environmental monitoring for alpha-emitting radionuclides from nuclear facilities and natural radioactivity sources was evaluated for particles in the size range of 0.03-0.1μm at different levels of face velocity. The SCE of the CMF was higher than that of the cellulose-glass fiber filter, and only the membrane filter showed the dependence of SCE on the particle size at higher face velocity. The use of the CMF at higher face velocity in environmental radioactivity monitoring leads to measurements of the background alpha spectrum with more degradation under the changing particle size condition in the atmosphere. Consequently, that fact needs to be taken into account, along with the expected particle size distribution and concentration of the airborne radioactivity being sampled, when selecting a face velocity to achieve the best possible detection limit.

Improvement of Adsorption Capacity by Refined Encapsulating Method of Activated Carbon into the Hollow-Type Spherical Bacterial Cellulose Gels for Oral Absorbent

To reduce the risk of adsorption of granular activated carbon (AC) in the gastrointestinal tract, we successfully prepared a hollow-type spherical bacterial cellulose gel encapsulated with AC (ACEG) and evaluated its pH tolerance and adsorption capacity. The bacterial cellulose gel membrane of ACEG features a three-dimensional mesh structure of cellulose fibers, allowing the selective permeation of substances based on their size. In this study, the preparation method of ACEGs was investigated, and the indole saturation adsorption capacity of the obtained gel was measured. We modified the gel culture nucleus gel from calcium alginate gel to agar gel, facilitating the encapsulation of previously challenging particles. The new preparation method used sodium hydroxide solution for sterilization and dissolution to remove the debris of Komagataeibacter xylinus, which was feared to remain in the bacterial cellulose membrane. This treatment was also confirmed to have no effect on the adsorption capacity of the AC powder. Therefore, this new preparation method is expected not only to improve the performance of ACEGs but also to be applied to a wide range of adsorbent-encapsulated hollow-type bacterial cellulose gels.

Bioengineering approach for the design of magnetic bacterial cellulose membranes

Biopolymer research has led to the development of novel products through innovative strategies. Their functionalization is typically achieved by physical/chemical methods that require harsh chemicals or mechanical treatments. These functionalities could be alternatively achieved by employing bioengineering design methods. We demonstrate, a bioengineered dual-microbial approach to create functional bacterial cellulose from microbial workhorses. Komagataeibacter hansenii ATCC 53582 is used to produce bacterial cellulose and engineered E. coli is used to functionalize the matrix with a recombinant fibrous protein. The E. coli harbours synthetic genes for the secretion of amyloid curli protein subunit (CsgA) tagged with short functional M6A peptide domains. The incorporation of M6A-functionalized amyloid proteins into bacterial cellulose facilitates magnetite nanoparticle nucleation. We achieved a saturation magnetization of 40 emu g−1, a three-fold increase compared to existing strategies. The magnetic bacterial cellulose films demonstrate cytocompatibility and accelerate cell migration in the presence of magnetic field.

Bacterial Cellulose Membrane Experimentally Implanted in the Peritoneum of Wistar Rats—Inflammatory Immunoreactivity and Oxidative Stress

Bacterial cellulose (BC) has been used for various applications; however, studies investigating the immunohistochemical characteristics of the inflammatory and scarring component in BC implanted in the peritoneum in vivo have not yet been fully described. This study aimed to evaluate the systemic and organic safety of BC through oxidative stress, blood, and serum biochemical markers, as well as the late inflammatory response in rats, using histopathology and immunohistochemistry. Forty-three rats (26 males; 17 females) received BC in the peritoneal cavity (implanted group—IG), while twenty-seven rats (12 males; 15 females) served as the control (sham group—SG). Sixty days after surgery, oxidative stress in tissues, blood biochemical markers, and histopathological and immunohistochemical analyses for lymphocytes, macrophages, collagen, and vascular response around the BC were assessed. Only one oxidative stress marker, glutathione peroxidase, was elevated in the liver of IG rats. Creatine kinase MB and lactate dehydrogenase levels were significantly lower in IG animals. Histopathological analysis showed granulomatous inflammation in 93% of IG rats, with 74% of mild intensity. Immunohistochemistry revealed a significant macrophage presence (F4/80), with CD3, CD20, and F4/80 markers indicating differences favoring macrophages. In conclusion, BC implantation in the peritoneum induces a foreign body granulomatous response with prominent macrophage presence (F4/80). Type I and III collagen were observed around the membrane, and vascularization was intense 60 days post-implantation. From a biochemical and oxidative stress perspective, BC seems to be a safe material to be used in the peritoneal cavity.

Surface Functionalization Strategy for Cellulose Membranes Based on Silanization and Thiol–Ene Click Chemistry

Surface Functionalization Strategy for Cellulose Membranes Based on Silanization and Thiol–Ene Click Chemistry

Cutting-Edge Applications of Cellulose-Based Membranes in Drug and Organic Contaminant Removal: Recent Advances and Innovations

The increasing environmental challenges caused by pharmaceutical waste, especially antibiotics and contaminants, necessitate sustainable solutions. Cellulose-based membranes are considered advanced tools and show great potential as effective materials for the removal of drugs and organic contaminants. This review introduces an environmentally friendly composite membrane for the elimination of antibiotics and dye contaminants from water and food, without the use of toxic additives. The potential of cellulose-based membranes in reducing the impact on water quality and promoting environmental sustainability is emphasized. Additionally, the benefits of using biobased cellulose membranes in membrane biological reactors for the removal of antibiotics from pharmaceutical waste and milk are explored, presenting an innovative approach to achieving a circular economy. This review provides recent and comprehensive insights into membrane bioreactor technology, making it a valuable resource for researchers seeking efficient methods to break down antibiotics in industrial wastewater, particularly in the pharmaceutical and dairy industries.

Eco-Friendly Photocatalytic Solutions: Synthesized TiO2 Nanoparticles in Cellulose Membranes for Enhanced Degradation of Indigo Carmine Dye.

This study focuses on comparing the efficiency of commercially available TiO2 (P25) with synthesized TiO2 nanoparticles (TiO2NP) impregnated in nonmodified cellulose membranes, specifically targeting the degradation of Indigo Carmine (IC) dye. We developed a novel method to enhance the interaction between cellulose and TiO2, thereby improving efficiency and reusability. This involves dissolving microcrystalline cellulose in 1-butyl-3-methylimidazolium chloride (BMImCl) and dispersing the TiO2 samples within this solution. The resulting cellulose membrane embedded with TiO2 nanoparticles (TiO2NP) exhibited a higher adsorption capacity and greater photocatalytic efficiency against IC compared to that of P25. This improvement is attributed to the larger surface area and increased reactivity of the synthesized TiO2NPs. Furthermore, the CEL_TiO2NP membranes demonstrated excellent stability and reusability, maintaining their catalytic efficiency over multiple cycles. This study presents new opportunities for developing efficient, reusable photocatalytic materials for environmental remediation using eco-friendly cellulose.

Analysis of a constant-volume diafiltration system with the ability to remove lithium cations when using poly(2-acrylamido-2-methyl-1-propanesulfonic acid) in water

This study describes the synthesis of a poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) and its application for the removal of Li+ in water using a constant-volume diafiltration system. PAMPS with molecular weights exceeding 100 kDa (88 % w/w), polymerisation yields of 97 % and high acidity was obtained. A block experimental design characterized the diafiltration system reporting: Regenerated cellulose (RC) and polyethersulfone (PES) ultrafiltration membranes with a molecular cut-off of 100 kDa can retain up to 1 % Li+ ions through surface charges. But when PAMPS 2000 kDa was used, 89 % of Li+ was removed (%R). Permeate flux (Js) decreases with increasing PAMPS:Li+ ratio, whereas the %R value increases. The filtration process is controlled by diffusion mechanisms according to the Peclet dimensionless number. Using PAMPS 100 kDa with a PAMPS:Li+ ratio (20:1), %R decreases to 76 %, whereas Js increases slightly. PAMPS can be reused 3 consecutive times, maintaining a Li+ cation rejection efficiency of >60 %. Additionally, it was found that the percentage of Li+ rejection capacity exercised with PAMPS is reduced to 60 % when Ca2+, K+, Mg2+ and Na+ cations are present.

In Vitro and In Vivo Biocompatibility of Bacterial Cellulose.

Bacterial cellulose is a unique biomaterial produced by various species of bacteria that offers a range of potential applications in the biomedical field. To provide a cost-effective alternative to soft-tissue implants used in cavity infills, remodeling, and subdermal wound healing, in vitro cytotoxicity and in vivo biocompatibility of native bacterial cellulose were investigated. Cytotoxicity was assessed using a metabolic assay on Swiss 3T3 fibroblasts and INS-1832/13 rat insulinoma. Results showed no cytotoxicity, whether the cells were seeded over or under the bacterial cellulose scaffolds. Biocompatibility was performed on Sprague-Dawley rats (males and females, 8 weeks old) by implanting bacterial cellulose membranes subcutaneously for 1 or 12 weeks. The explanted scaffolds were then sliced and stained with hematoxylin and eosin for histological characterization. The first series of results revealed acute and chronic inflammation persisting over 12 weeks. Examination of the explants indicated a high number of granulocytes within the periphery of the bacterial cellulose, suggesting the presence of endotoxins within the membrane, confirmed by a Limulus amebocyte lysate test. This discovery motivated the development of non-pyrogenic bacterial cellulose scaffolds. Following this, a second series of animal experiments was done, in which materials were implanted for 1 or 2 weeks. The results revealed mild inflammation 1 week after implantation, which then diminished to minimal inflammation after 2 weeks. Altogether, this study highlights that unmodified, purified native bacterial cellulose membranes may be used as a cost-effective biomedical device provided that proper endotoxin clearance is achieved.

Lithiophilic Protective Dual Layer Enabling Stable Electrodeposition of Lithium at High Current Density

Lithium (Li) is an ideal anode material for rechargeable batteries and thus manufacturing Li metal is crucial for the practical development of Li metal batteries. Electrodeposition is an efficient technique for producing ultrathin and scalable Li metal electrodes. However, the dendritic growth and the side reactions of Li with electrolyte during the electrodeposition are the main obstacles to overcome. In this study, we designed a pre-coated protective dual layer (PDL) composed of a poly(ethylene oxide)-based solid polymer electrolyte (SPE) and a polydopamine-coated cellulose membrane (PD-CM). The adhesive and ion-conductive SPE layer suppressed the growth of Li dendrites and side reactions with liquid electrolyte. The PD-CM layer with high porosity and lithiophilicity promoted a facile and uniform Li-ion flux. By applying the pre-coated PDL, Li was uniformly electrodeposited on the Ag-coated Cu at a high current density of 6 mA cm−2. The Li/LiFePO4 cell composed of an electrodeposited Li anode with PDL and a LiFePO4 cathode was assembled without an additional separator, and its cycling performance was evaluated. The cell initially delivered a high discharge capacity of 154.8 mAh g−1 at 45 °C and exhibited excellent cycling stability with a capacity retention of 97.0% after 200 cycles.

Hydrothermally rearranged cellulose membranes for controlled size sieving

Biodegradable polymers are important for reducing pollution and promoting sustainability as they break down more easily than traditional petroleum-based polymers. One such polymer is regenerated cellulose (RC), which is widely used in water purification and pharmaceuticals due to its chemical resistance and hydrophilicity. Since its direct use of cellulose is limited by its insolubility, derivatives like cellulose acetate (CA) are first converted through a regeneration process back into RC to make use of its functional properties. During this process, however, the membrane structure may be compromised, impairing its separation performance. Here we show that simply soaking CA membranes in hot water before regeneration significantly improves the structural integrity of RC membranes, retaining the sieving properties. The pretreatment causes planar shrinkage without disrupting the general characteristics of cellulose, allowing for sole adjustment of pore size. This straightforward approach enables precise tuning of membrane pore properties to suit specific application, such as adjusting pore size for efficient sieving of materials with particular molecular masses, all while maintaining high water permeance. Our findings suggest that hydrothermal processing has the potential to enhance the filtration performance of RC membranes and broaden their range of applications.

Enhancing the Separation Performance of Cellulose Membranes Fabricated from 1-Ethyl-3-methylimidazolium Acetate by Introducing Acetone as a Co-Solvent

Cellulose, a sustainable raw material, holds great promise as an ideal candidate for membrane materials. In this work, we focused on establishing a low-cost route for producing cellulose microfiltration membranes by adopting a co-solvent system comprising the ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) and acetone. The introduction of acetone as a co-solvent into the casting solution allowed control over the viscosity, thereby significantly enhancing the morphologies and filtration performances of the resulting cellulose membranes. Indeed, applying this co-solvent allowed the water permeability to be significantly increased, while maintaining high rejections. Furthermore, the prepared cellulose membrane demonstrated excellent fouling resistance behavior and flux recovery behavior during a challenging oil-in-water emulsion filtration. These results highlight a promising approach to fabricate high-performance cellulose membranes.

Self-Assembly of Soft and Conformable Broadband Absorbing Nanocellulose-Gold Nanoparticle Composites.

Broadband light-absorbing materials are of large interest for numerous applications ranging from solar harvesting and photocatalysis to low reflection coatings. Fabrication of these materials is often complex and typically utilizes coating techniques optimized for flat and hard materials. Here, we show a self-assembly based strategy for generating robust but mechanically flexible broadband light-absorbing soft materials that can conform to curved surfaces and surface irregularities. The materials were fabricated by adsorbing large quantities of gold nanoparticles (AuNPs) on the nanofibrils of hydrated bacterial cellulose (BC) membranes by tailoring the interaction potential between the cellulose nanofibrils and the AuNPs. The highly efficient self-assembly process resulted in very dense multilayers of AuNPs on the nanofibrils, causing extensive broadening of the localized surface plasmon resonance band and a striking black appearance of the BC membranes. The nanocomposite materials showed an absorptance >96% in both the visible and the near-infrared wavelength range. The AuNP-functionalized BC membranes demonstrated excellent conformability to curved and structured surfaces and could adopt the shape of highly irregular surface structures without any obvious changes in their optical properties. The proposed self-assembly based strategy enables the fabrication of soft and conformable broadband light-absorbing nanocomposites with unique optical and mechanical properties using sustainable cellulose-based materials.

Optimization and Modification of Bacterial Cellulose Membrane from Coconut Juice Residues and Its Application in Carbon Dioxide Removal for Biogas Separation

Driven by environmental and economic considerations, this study explores the viability of utilizing coconut juice residues (CJRs), a byproduct from coconut milk production, as a carbon source for bacterial cellulose (BC) synthesis in the form of a versatile bio-membrane. This work investigates the use of optimization modeling as a tool to find the optimal conditions for BC cultivation in consideration of waste minimization and resource sustainability. Optimization efforts focused on three parameters, including pH (4–6), cultivation temperature (20–30 °C), and time (6–10 days) using Design Expert (DE) V.13. The maximum yield of 9.31% (g/g) was achieved when the cultivation took place at the optimal conditions (pH 6, 30 °C, and 8 days). This approach aligns with circular economy principles, contributing to sustainable resource management and environmental impact reduction. The experimental and predicted optimal conditions from DE V.13 were in good agreement, validating the study’s outcomes. The predictive model gave the correlations of the optimal conditions in response to the highest yield and maximum eco-efficiency. The use of prediction modeling resulted in a useful tool for forecasting and obtaining guidelines that can assist other researchers in calculating optimal conditions for a desired yield. Acetylation of the BC resulted in cellulose acetate (CA) membranes. The CA membrane exhibited the potential to separate CO2 from a CH4/CO2 mixed gas with a CO2 selectivity of 1.315 in a membrane separation. The promising gas separation results could be further explored to be utilized in biogas purification applications.

Engineering a Biomimetic Glomerular Filtration Barrier: Coculturing Endothelial Podocytes on Kidney ECM-Bacterial Cellulose Membrane Hybrid.

A novel avenue for advancing our understanding of kidney disease mechanisms and developing targeted therapeutics lies in overcoming the limitations of the existing in vitro models. Traditional animal models, while useful, do not fully capture the intricacies of human kidney physiology and pathophysiology. Tissue engineering offers a promising solution, yet current models often fall short in replicating the complex microarchitecture and biochemical milieu of the kidney. To address this challenge, we propose the development of a sophisticated in vitro glomerular filtration barrier (GFB) utilizing advanced biomaterials and a kidney decellularized extracellular matrix (kdECM). In our approach, we employ a bacterial cellulose membrane (BC) as a scaffold, providing a robust framework for cell growth and interaction. Coating this scaffold with kdECM hydrogel derived from caprine kidney tissue via a detergent-free decellularization method ensures the preservation of vital extracellular matrix proteins crucial for cellular compatibility and signaling. Our engineered GFB not only supports the growth of endothelial and podocyte cells but also exhibits the presence of key markers such as CD31 and nephrin, indicating successful cellular integration. Furthermore, the expression of collagen IV, an essential extracellular matrix (ECM) protein, validates the fidelity of our model in simulating cellular interactions within a kdECM matrix. Additionally, we assessed the filtration efficiency of the developed GFB model using albumin, a standard protein, to evaluate its performance under conditions that closely mimic the native physiological environment. This innovative approach, which faithfully recapitulates the native microenvironment of the glomerulus, holds immense promise for elucidating kidney disease mechanisms, conducting permeability studies, and advancing personalized therapeutic strategies. By leveraging cutting-edge biomaterials and tissue-specific coculture technology, this study can be further extended to develop GFB for the treatment of renal diseases, ultimately improving patient outcomes and quality of life.

Composite Membranes of Polyhydroxyalkanoate and Cellulose for Depth Filtration

Composite Membranes of Polyhydroxyalkanoate and Cellulose for Depth Filtration

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.

Bacterial Cellulose Incorporating Multicolor Fluorescent Probes for Visual Acidity Detection in Paper-Based Cultural Relics.

Paper-based cultural relics often undergo acidification and deterioration during long-term preservation. Accurate detection of paper acidity is of great significance to assess aging status and extend the preservation lifetime of paper-based cultural relics. Rapid identification of the acidification degree and acid distribution across multiple regions of paper is essential. Inspired by fluorescent sensing technology, pH-sensitive cadmium telluride (CdTe) quantum dots (QDs) and rhodamine B (RB) fluorescent probes are synthesized and incorporated onto the nanofibers of a bacterial cellulose (BC) membrane to enable visual acidity detection of paper. Due to the complementary pH detection range of CdTe QDs and RB probes, the composite BC membrane exhibits a clear pH response across an acidic to neutral range (pH 3.0-7.5). Notably, the contrasting fluorescent colors of the two probes within the BC membrane allow for easy visualization of paper pH and acidity distribution with the naked eyes. A distinct color transition from red to green was observed on the fluorescent BC membrane when it is applied to a model paper with a gradient pH distribution. The feasibility of this method was verified by using the flat-headed pH electrode method. Additionally, common metal ions in most paper fillers, inks, pigments, as well as some sugars and amino acids showed minimal interference with the pH response of the composite BC membrane, highlighting its potential and broad applicability for visual acidity detection in paper-based cultural relics.

Reduction in Olfactory Discomfort in Inhabited Premises from Areas with Mofettas through Cellulosic Derivative-Polypropylene Hollow Fiber Composite Membranes.

Hydrogen sulfide is present in active or extinct volcanic areas (mofettas). The habitable premises in these areas are affected by the presence of hydrogen sulfide, which, even in low concentrations, gives off a bad to unbearable smell. If the living spaces considered are closed enclosures, then a system can be designed to reduce the concentration of hydrogen sulfide. This paper presents a membrane-based way to reduce the hydrogen sulfide concentration to acceptable limits using a cellulosic derivative-propylene hollow fiber-based composite membrane module. The cellulosic derivatives considered were: carboxymethyl-cellulose (NaCMC), P1; cellulose acetate (CA), P2; methyl 2-hydroxyethyl-cellulose (MHEC), P3; and hydroxyethyl-cellulose (HEC), P4. In the permeation module, hydrogen sulfide is captured with a solution of cadmium that forms cadmium sulfide, usable as a luminescent substance. The composite membranes were characterized by SEM, EDAX, FTIR, FTIR 2D maps, thermal analysis (TG and DSC), and from the perspective of hydrogen sulfide air removal performance. To determine the process performances, the variables were as follows: the nature of the cellulosic derivative-polypropylene hollow fiber composite membrane, the concentration of hydrogen sulfide in the polluted air, the flow rate of polluted air, and the pH of the cadmium nitrate solution. The pertraction efficiency was highest for the sodium carboxymethyl-cellulose (NaCMC)-polypropylene hollow fiber membrane, with a hydrogen sulfide concentration in the polluted air of 20 ppm, a polluted air flow rate (QH2S) of 50 L/min, and a pH of 2 and 4. The hydrogen sulfide flux rates, for membrane P1, fall between 0.25 × 10-7 mol·m2·s-1 for the values of QH2S = 150 L/min, CH2S = 20 ppm, and pH = 2 and 0.67 × 10-7 mol·m-2·s-1 for the values of QH2S = 50 L/min, CH2S = 60 ppm, and pH = 2. The paper proposes a simple air purification system containing hydrogen sulfide, using a module with composite cellulosic derivative-polypropylene hollow fiber membranes.

Development of charged membranes for the ultrafiltration of siRNA

RNA interference (RNAi) is an exciting new therapeutic approach, using small interfering RNA (siRNA) to silence specific genes for treating various diseases. Ultrafiltration has been widely used for the concentration and purification of monoclonal antibodies and other biotherapeutics; however, its application in the downstream processing of double-stranded oligonucleotides remains underexplored. This study investigates the use of ultrafiltration in the final formulation for concentrating a siRNA drug substance. Initial experiments were conducted with Ultracel™ composite regenerated cellulose membranes over a range of molecular weight cutoffs (MWCO) at different siRNA feed concentrations. Results demonstrated significant effects of both fouling and concentration polarization, with the maximum achievable concentration falling well below the target required for subcutaneous injection. Novel surface-modified ultrafiltration membranes were made by reaction of the cellulose with bromopropanesulfonic acid. These negatively charged membranes showed improved siRNA retention, reduced fouling, and a large increase in the maximum achievable siRNA concentration (from 52 to >180 mg/mL). These findings offer critical insights into novel approaches for developing high performance ultrafiltration processes for siRNA concentration.