Natural Cellulosic Materials Research Articles

Equilibrium and optimization of water-heat transfer in natural cellulose-based hybrid hydrogel for efficient solar desalination

Solar interfacial evaporation for seawater desalination and wastewater purification is considered a promising strategy to alleviate the water scarcity crisis. Currently, the ways to improve evaporators usually revolve around iteration of photothermal materials (enhancing heat generation) or macrostructural remodeling (altering water transport rate), but these means have limitations and do not achieve simultaneous and precise regulation of water-heat utilization. Herein, a simple hydrothermal method is used to synthesize natural cellulose-based hybridized hydrogels, exhibiting a high evaporation efficiency (97.67%) and a full range of water purification capabilities, including antimicrobial, anti-salt accumulation, and degradation of organic dyes. Significantly, the enhancement mechanism of the energy-mass utilization of this evaporator can be explained from two aspects. Firstly, the hybridization of natural cellulose and inorganic carbon materials can supplement a large number of hydrophilic functional groups, thus fully activating the water molecules and reducing the evaporation energy consumption. Furthermore, the COMSOL simulation is used to clarify the distribution of water and heat, and by adjusting the height of the hydrogel, the balance of water-heat transfer is cleverly achieved with the maximization of energy utilization. Overall, the optimization idea of water-heat transfer provides a new direction for future evaporator design and a fresh opportunity for the improvement of energy-mass management model.

Traditional and biodegradable plastics host distinct and potentially more hazardous microbes when compared to both natural materials and planktonic community

Microplastic particles are persistent micropollutants that provide a substrate for the growth of bacterial biofilms, posing a threat to the environment. This study explores the changes in commercially available food containers made of conventional (polypropylene PP, polyethylene terephthalate PET), innovative biodegradable (Mater-Bi) and natural (wood and cellulose) materials, when introduced in the surface waters of Lake Maggiore for 43 days. Spectral changes revealed by FT-IR spectroscopy in PET and Mater-Bi, and changes in thermal properties of all human-made material tested indicated a degradation process occurred during environmental exposure. Despite similar bacterial richness, biofilms on PET, PP, and Mater-Bi differed from natural material biofilms and the planktonic community. Human-made material communities showed a higher proportion of potential pathogens, with PET and PP also exhibiting increased abundances of antibiotic resistance genes. Overall, these findings stress the need for dedicated strategies to curb the spread of human-made polymers in freshwaters, including innovative materials that, due to their biodegradable properties, might be perceived less hazardous for the environment.

Laser speckle-based estimation of surface condition for designing quieter material

Laser speckle is a non-contact, non-interfering, non-destructive, rapid and controllable technique with a large area of coverage that has attracted much attention for surface analysis of materials. The emergence of different natural cellulosic materials as potential candidates for the replacement of synthetic ones is promising, but their sustainability from the point of view of material design is still in question. Machining of the surface of cellulosic components for making sound-dampening materials has a critical effect on determining their surface condition. Laser speckle is an emerging tool for surface analysis of a variety of materials, and it has important applications in material design and analysis. As a cutting-edge research tool, ultrasonic wave technology has maintained a significant contribution to the design and structural monitoring of composite materials. The present work uses date palm leaf fibers for composite reinforcement. The sound-dampening properties, such as sound absorption and transmission, were analyzed on the basis of surface roughness observed with the laser speckle technique and modified by ultrasonically blended surfactants. The surface roughness of the synthesized material was found to increase with sonication time with an R 2 value of 0.944 and observed fluctuation in roughness data on the surface of the material. The sound absorption coefficient is 0.98 with a transmission loss of 60 dB, for which the material is classified as an ASTM E1050 Class A acoustic material. Further, the method of laser speckle-based roughness estimation is found to be potential tool for the design of any type of quieter material.

Cellulose-based materials for carbon capture and conversion

With the worldwide attention on decreasing carbon dioxide (CO2) emissions, carbon capture and storage (CCS) is utilized to stop CO2 from escaping into the atmosphere. Selecting appropriate materials is crucial for the establishment of a dependable and secure carbon capture and storage technology infrastructure. The natural cellulose materials possess inherent characteristics such as eco-friendliness, high utility, remarkable physical and mechanical properties, which make them particularly available for CCS. In the field of carbon capture, utilization and sequestration technologies, cellulose-based materials can be used as adsorbents for CO2 capture and as catalyst carriers for CO2 conversion. Firstly, the application of cellulose-based materials in carbon capture and conversion is introduced. Secondly, the research progress of cellulose-based films, aerogels and solid adsorbents in the field of carbon capture are summarized. Subsequently, the research mechanisms of cellulose-based materials for the conversion of CO2 to methanol format, carbonate and CO are also described in detail. Finally, the challenges and the key problems of cellulose-based materials in carbon capture and utilization are described.

Wet-resistant, dustproof, and germproof self-powered lignocellulosic triboelectric filters for respiratory protection, monitoring, and diagnosis

The moisture sensitivity and structural defects found in natural cellulose materials limit their ability to serve as substitutes for petroleum-based masks. This study uses a combination of methods, including retaining lignin, embedding silver particles in situ, and using a mixture of coarse and fine fibers to enhance the wet resistance, antibacterial properties, and triboelectric output of lignocellulosic materials. This approach also aimed to balance pressure drop and filtration efficiency. A triboelectric filter (Ag-LCTEF) using a perforated fluorinated ethylene propylene (FEP) film sandwiched between two sheets of Ag-embedded lignocellulose (Ag-LC) was assembled. The resulting Ag-LCTEF enabled self-powered continuous monitoring of breathing signals, boasting impressive submicron particle removal (99.70 %) and antibacterial efficiency (99.18 %), all while maintaining a relatively low-pressure drop of 76 Pa. Notably, the Ag-LCTEF displayed consistent performance and long-term durability even in high humidity conditions of 80 % RH. These remarkable achievements have spurred the suggestion of integrating respiratory protection, monitoring, and diagnostic functions, showcasing its potential for the next generation of wearable electronics. Moreover, naturally safe and biodegradable lignocellulose serves as an environmentally friendly replacement for petroleum-based materials.

Natural Cellulose-Based Multifunctional Nanofibers for the Effective Removal of Particulate Matter and Volatile Organic Compounds.

Multifunctional nanofibers for particulate matter (PM) and volatile organic compounds (VOCs) removal from the indoor atmospheric environment were manufactured from eco-friendly natural cellulose materials via electrospinning using an optimized solvent system containing 1-ethyl-3-methylimidazolium acetate (EmimAC) and dimethylformide (DMF) in a 3:7 volume ratio. EmimAC improved the cellulose stability, whereas DMF improved the electrospinnability of the material. Various cellulose nanofibers were manufactured using this mixed solvent system and characterized according to the cellulose type, such as hardwood pulp, softwood pulp, and cellulose powder, and cellulose content ranging from 6.0-6.5 wt%. The correlation between the precursor solution alignment and electrospinning properties indicated an optimal cellulose content of 6.3 wt% for all cellulose types. The hardwood pulp-based nanofibers possessed the highest specific surface area and exhibited high efficiency for eliminating both PM and VOCs, with a PM2.5 adsorption efficiency of 97.38%, PM2.5 quality factor of 0.28, and toluene adsorption of 18.4 mg/g. This study will contribute to the development of next-generation eco-friendly multifunctional air filters for indoor clean-air environments.

Filtration Capacity and Radiation Cooling of Cellulose Aerogel Derived from Natural Regenerated Cellulose Fibers

ABSTRACT Natural cellulosic materials are attractive biopolymers for their naturally abundant source, mechanical toughness, bioactivity, etc. However, porosity and flexibility remain challenges for the preparation of aerogels from natural cellulose. To maintain the characteristics of cellulose aerogels possessing the toughness of fibers and high porosity of aerogels, cellulose aerogels with three-dimensional void structures and high compressive resilience were prepared by mixing cellulose fiber suspension and polyvinyl alcohol (PVA). The PM 2.5 removal rate and thermal conductivity of cellulose aerogel reached 92.4% and 0.028 W/mK, respectively, when a PVA content of 0.7% was added, and the radiation cooling temperature was about 10.0°C lower than that of PE foam. The three-dimensional void structure and surface morphology of the cellulose aerogels were investigated by scanning electron microscopy (SEM). The cellulose aerogel porosity and pore size distribution were evaluated by a mercury intrusion meter. The crystal structure of cellulose was analyzed by X-ray diffraction (XRD). UV-Vis-NIR spectroscopy was used to investigate the infrared reflectance of cellulose aerogels. Then the air purification efficiency and radiation cooling effect of porous cellulose aerogels were evaluated in a homemade device, respectively.

Isolation and characterization of novel agrowaste‐based cellulosic micro fillers from Borassus flabellifer flower for polymer composite reinforcement

AbstractNowadays, interest in new natural cellulosic materials is increasing due to their higher properties and the motivation for researchers to advance high‐performance bio‐based composites. This study aimed at understanding the physicochemical and morphological properties, crystallinity, and thermal behavior of Borassus flabellifer flower micro‐sized cellulosic fillers. Cellulose has some unique properties, such as good mechanical properties, low density, biocompatibility, thermal stability, and biodegradability. The acid hydrolysis method was used to extract cellulose from the dried B. flabellifer flower. The crystallinity index value and crystalline size were calculated through X‐ray diffraction for the extracted microcrystalline cellulose and found to be 69.81% and 70.73 nm, respectively. The morphology of the extracted cellulosic filler was investigated by scanning electron microscopy and ImageJ software. The average size of the micro filler was found to be 26 μm. The Fourier transform infrared spectroscopy showed the extracted cellulose fillers being free from lignin, hemicelluloses, and other non‐cellulosic materials. Atomic force microscopy revealed that the surface roughness of the cellulose was less than 66 nm. The results showed that an agricultural residue can be converted into a valuable micro‐sized cellulosic filler material for polymeric composite applications that can withstand processing temperature up to 200°C. Here, the naturally occurring source of B. flabellifer flower could be used as a valuable substitute for more traditional sources like wood and cotton for the production of nanocellulose, nano‐additives, or nano‐reinforcing agents for water‐soluble biopolymers.

Self-assembling hierarchical flexible cellulose films assisted by electrostatic field for passive daytime radiative cooling

Natural cellulose materials possess hierarchical microstructures and high crystallinity, which gives the possibility to develop high-performance cellulose structural materials. However, the hierarchical microstructures of natural cellulose materials will be disappeared in regenerated cellulose materials owing to the dissolution process. Achieving hierarchical microstructures and high crystallinity as natural cellulose materials in flexible regenerated cellulose materials is an arduous challenge. Herein, a simple electrostatic-field-assisted self-assembly strategy is proposed to greatly boost the crystallization of regenerated cellulose materials and obtain hierarchical flexible fibrous cellulose film. Large areas of cellulose crystallites with the lattice spacing close to monoclinic cellulose II are presented, and crystallinity as high as 71.0 % is achieved for the self-assembled fibrous cellulose film. Moreover, the self-assembled cellulose film has a bioinspired fibrous morphology with anisotropic hierarchical microstructures, and therefore can be used as flexible passive daytime radiative cooling materials with subambient cooling up to 11.3 °C in hot summer. It is the first time to realize high crystallinity and hierarchical microstructures in regenerated cellulose materials by the self-assembly of cellulose macromolecules at the molecular level. This strategy provides new perspectives for the development of advanced flexible cellulose materials with hierarchical microstructures and high crystallization from natural cellulose resources.

Development of Water Repellency on Jute Fabric by Chemical Means for Diverse Textile Uses

Jute is one of the natural cellulosic textile materials. It has many advantageous properties similar to cotton. Jute fibre has potential to impart different functionality by different chemical finishing for its diversification. In this research, Water repellent jute fabrics have been prepared by treating Nova TTC (fluorocarbon compound) different ratio and to find out the best formulation recipe. Treating fabrics have been impaired with a water repellent characteristic and showing good rating result on jute fabric .This water repellent fabric was suitable of various jute products for diverse textile uses.

Investigation of Egyptian Chorisia spp. fiber as a natural sorbent for oil spill cleanup

Egyptian hollow fiber has been explored as natural feasible cellulosic materials that acquired great lumen and hydrophobic characteristics, which empower it to show high oil sorption capacity. The effect of solvent and sodium chlorite treatments and oil type on the sorption characteristics of Egyptian Chorisia spp. hollow fibers have been investigated. The outcomes demonstrate that with the exception of non-polar solvent, ether, Chorisia hollow fiber treated with other solvents show reduction of oil sorption capacity. NaClO2-treated fiber appears the highest and selective absorption of oil from oil/water mixtures and stayed stable after ten sorption/desorption cycles of reutilization with only 15% of sorption limit decrease. Besides, in view of SEM, NaClO2-treated fiber was retained its overall tubular and lumen structures after desorption of oils. These achievements will be reflected in the challenges for purification of other sources of water if there should arise an occurrence of water lack in Egypt.

High-efficiency and durable removal of water-in-heavy oil emulsions enabled by delignified and carboxylated basswood with zwitterionic nanohydrogel coatings

HypothesisIt is hypothesized that grafting zwitterionic nanohydrogel (ZNG) helps to achieve anti-asphaltene properties on cellulosic substrates, thus overcoming the fouling issue of natural cellulosic materials for treating oily emulsions. It is also hypothesized that ZNG coatings enhance the water-binding affinity of the substrates, resulting in an outstanding water-removal performance on asphaltene-stabilized emulsions with long-term stability. ExperimentsA cellulosic substrate was derived from nature basswood via a sequence of delignification and carboxylation processes. The ZNG-DBS composite was then developed by esterification to covalently graft ZNGs on the inner channels of the substrate. The water-binding affinity, wettability, water-removal performance for treating water in asphaltene-stabilized emulsions were evaluated via characterizing the filtration/absorption, and anti-fouling mechanism of the ZNG-DBS. FindingsZNG coatings enhance the hydration capability of the basswood substrate, allowing it to absorb water emulsion droplets protected by asphaltenes in the oil medium without being contaminated. Moreover, superior and stable removal capabilities were achieved by using this unique material to treat asphaltenes-stabilized water-in-oil emulsions with the water residue content of <1.0 and ∼0.065 wt% via cyclic filtration and absorption tests, respectively. Our results demonstrate the successful conversion of widely accessible wood resources to functional materials with great potential in the practical treatment of oily wastewater.

Cellulose Nanocrystals Facilitate Needle-like Ice Crystal Growth and Modulate Molecular Targeted Ice Crystal Nucleation.

Ice nucleators are of crucial and important implications in various fields including chemistry, climate, agriculture, and cryobiology. However, the complicated extract and biocompatibility of ice nucleators remain unresolved, and the mechanism of ice nucleation remains largely unknown. Herein, we show that natural nanocrystalline cellulose materials possess special properties to enhance ice nucleation and facilitate needle-like ice crystal growth. We reveal the molecular level mechanism that the efficient exposure of cellulose hydroxyl groups on (-110) surface leads to faster nucleation of water. We further design chitosan-decorated cellulose nanocrystals to accomplish molecular cryoablation in CD 44 high-expression cells; the cell viability shows more than ∼10 times decrease compared to cryoablation alone and does not show evident systematic toxicity. Collectively, our findings also offer improved knowledge in molecular level ice nucleation, which may benefit multiple research communities and disciplines.

Novel fabrication of cellulose sprinkled crystalline nanocomposites using economical fibrous sources: High performance, compatible catalytic and electrochemical properties

We report an innovative green synthesis of cellulose based copper oxide nanomaterials by simple sol-gel derived solvo-thermal method. The physio-chemical properties of nanocomposite has enhanced by dissolving filter paper, cotton (Gossypium) and kapok cotton (Ceiba pendantra) as natural cellulose materials in cuprammonium hydroxide (Schweizer's reagent). Hybrid of polysaccharide-copper oxide nanocomposite has exhibited versatility. The composites were characterized by XRD, FESEM-EDAX, HRTEM, FT-IR, UV–Vis, CV, GCD and EIS studies. The sharp XRD peaks have confirmed the crystalline monoclinic phase of CuO as well as crystalline cellulosic materials with crystalline size of 55.7 nm. The observed FT-IR peaks at 523.19 and 1118 cm−1 has proved the Cu–O stretching as well as C–O linkage in cellulose material respectively. The UV–Vis study of nanocomposites has confirmed the specific absorption property of synthesized nanomaterials. The redox peaks in CV and GCD curve have confirmed that the synthesized nanocomposites are the very good energy storage material with the specific capacitance value of 120 F g-1 at the current density of 1 A g-1. They have showed an effective antimicrobial activity against gram positive as well as gram negative bacterial strains and also exhibited good catalytic activity as heterogeneous catalyst in esterification of biodiesel production for industrial applications.

Green modification of cellulose-based natural materials by HRP-initiated controlled “graft from” polymerization

Considerable attention has been focused on the application of natural cellulosic materials due to the cost-effectiveness, renewability, and biodegradability of cellulose. However, gaps between cellulose-based and petroleum-based materials still exist. In this study, a green, environmental modification method for cellulose by enzyme-initiated reversible addition fragmentation chain transfer (RAFT) graft polymerization was reported. First, the grafting of acryloyl chloride (AC) provided reaction sites on cellulosic fiber surfaces, followed by the enzymatic RAFT graft polymerization of acrylamide (AM). The grafting of well-controlled polyacrylamide (PAM) chains on the cellulosic material surface was verified by Fourier transform infrared spectrometer (FTIR), X-ray photoelectron spectroscopy (XPS), and the controlled grafting ratio was also estimated. The transition of wetting behaviors after the modification of AC and PAM also provided evidence for successful grafting on cellulosic materials. In addition, this method can be well applied for the preparation of various functional cellulosic materials.

Cellulose Nanomaterials in Interfacial Evaporators for Desalination: A "Natural" Choice.

Herein, the recent advances in realizing highly efficient cellulose-based solar evaporators for alleviating the global water crisis are summarized. Fresh water scarcity is one of the most threatening issues for sustainable development. Solar steam generation, which harnesses the abundant sunlight, has been recognized as a sustainable approach to harvest fresh water. In contrast to synthetic polymeric materials that can pose serious negative environmental impacts, cellulose-based materials, owing to their biocompatibility, renewability, and sustainability, are highly attractive for realizing solar steam generators. The molecular and macromolecular features of cellulose and the physicochemical properties of extracted cellulose nanoparticles (cellulose nanocrystals and cellulose nanofibrils (CNF)) and natural cellulose materials (wood and bacterial nanocellulose (BNC)) that make them attractive as supporting substrate materials in solar steam generators are briefly discussed. Recent progress in designing highly efficient cellulose-based solar evaporators, including utilizing extracted cellulose nanoparticles via bottom-up assembly CNF, natural cellulose materials with intrinsic hierarchical structure (wood and BNC), and commercial planar cellulose substrates (air-laid paper, cellulose paper, and cotton fabric) is reviewed. The outstanding challenges that need to be addressed for these materials and devices to be utilized in the real-world and in overcoming global water crisis are also briefly highlighted.

Microplastic study reveals the presence of natural and synthetic fibres in the diet of King Penguins (Aptenodytes patagonicus) foraging from South Georgia

Marine ecosystems are experiencing substantial disturbances due to climate change and overfishing, and plastic pollution is an additional growing threat. Microfibres are among the most pervasive pollutants in the marine environment, including in the Southern Ocean. However, evidence for microfibre contamination in the diet of top predators in the Southern Ocean is rare. King Penguins (Aptenodytes patagonicus) feed on mesopelagic fish, which undergo diel vertical migrations towards the surface at night. Microfibres are concentrated in surface waters and sediments but can also be concentrated in fish, therefore acting as contamination vectors for diving predators feeding at depth. In this study, we investigate microfibre contamination of King Penguin faecal samples collected in February and March 2017 at South Georgia across three groups: incubating, chick-rearing and non-breeding birds. After a KOH digestion to dissolve the organic matter and a density separation step using a NaCl solution, the samples were filtered to collect microfibres. A total of 77% of the penguin faecal samples (36 of 47) contained microfibres. Fibres were measured and characterized using Fourier-Transform Infrared spectroscopy to determine their polymeric identity. Most fibres (88%) were made of natural cellulosic materials (e.g. cotton, linen), with only 12% synthetic (e.g. polyester, nylon) or semi-synthetic (e.g. rayon). An average of 21.9 ± 5.8 microfibres g−1 of faeces (lab dried mass) was found, with concentrations more than twice as high in incubating penguins than in penguins rearing chicks. Incubating birds forage further north at the Antarctic Polar Front and travel longer distances from South Georgia than chick-rearing birds. This suggests that long-distance travelling penguins are probably more exposed to the risk of ingesting microfibres when feeding north of the Antarctic Polar Front, which might act as a semi-permeable barrier for microfibres. Microfibres could therefore provide a signature for foraging location in King Penguins.

Impact of plasma treatment on acoustic properties of natural cellulose materials

Low-temperature plasma is widely used in many surface treatment technologies for modifications of the physical properties of different polymeric materials. In the present work, we have examined the modification of acoustical properties of natural cellulose materials (cotton, hemp) by the radio-frequency argon plasma. We have observed an increase of the sound absorption coefficient due to the plasma treatment for certain range of applied powers. An analysis of elementary processes which happened during plasma–material interaction was conducted. Additional analyses related to material characterizations were performed in order to resolve structural and chemical changes of plasma treated materials. The micro-mechanical modification of treated materials, which happened upon the retrieved structural and chemical changes, was related to the modification of its acoustical properties in order to explain the observed effect.

Increased loadability of transformers using natural ester and cellulosic materials as high temperature insulation systems

The use of natural ester–filled transformers started in 1996, with two industrial transformers installed at the Cooper Power System factory to provide power for two core annealing ovens. Investigations conducted according to the IEEE C57.100 accelerated transformer life test method (Lockie Test) [1] and the sealed tube accelerated insulating system material life test method [2]–[4] indicated a possible extension of transformer life, associated with reduction of the paper degradation rate when impregnated with natural ester liquids.

Investigation of Waste Paper Cellulosic Fibers Utilization into Cement Based Building Materials

Recently, the utilization of renewable natural cellulosic materials, such as wood, plants, and waste paper in the preparation of building materials has attracted significant interest. This is due to their advantageous properties, low environmental impact and low cost. The objective of this paper is to investigate the influence of recycled cellulosic fibers (in the amount 0.5 wt % of the filler and binder weight) and superplasticizer (in the amount 0.5 wt % of the cement weight) on the resulting properties of cement composites (consistency of fresh mixture, density, thermal conductivity, and compressive and flexural strength) for hardening times of 1, 3, 7, 28, and 90 days. Plasticizer use improved the workability of fresh cement mixture. In comparison to the reference sample, the results revealed a decrease in density of 6.8% and in the thermal conductivity of composites with cellulosic fibers of 34%. The highest values of compressive (48.4 MPa) and flexural (up to 7 MPa) strength were achieved for hardened fiber cement specimens with plasticizer due to their significantly better dispersion of cement particles and improved bond strength between fibers and matrix.