Multifunctional Cellulose Research Articles

Multifunctional Nanomaterials Modification of Cellulose Paper for Efficient Triboelectric Nanogenerators

AbstractThere is a need to develop inexpensive, lightweight, and flexible high‐performance triboelectric nanogenerators (TENGs) from renewable resources. Here, a multifunctional cellulose filter paper (CFP)‐based TENG consisting of dielectric Ti0.8O2 nanosheets (Ti0.8O2 NSs) and conducting Ag nanoparticles (Ag NPs) is prepared by a simple dip coating method. The incorporation of dielectric Ti0.8O2 NSs onto the CFP significantly improves charge generation, while the inclusion of Ag NPs provides an electrically conductive path for charge transportation. The presence of these fillers can be deduced from XRD, SEM, EDS, X‐ray photoelectron spectroscopy, and Raman spectroscopy. Their distribution is visualized in 3D by synchrotron radiation X‐ray tomography. The present CFP‐based TENG provides an output voltage and current density of ≈42 V and ≈1 µA cm−2, respectively with the power density of ≈25 µW cm−2. It is capable of lighting up 40 light‐emitting diode bulbs and charging a 0.22 µF capacitor to 8 V in only 5 s. The developed TENG is also capable of detecting simple human motions, i.e., finger tapping, finger rubbing, and foot trampling. This work offers a facile design of low cost yet efficient paper‐based TENG by dual modification with multifunctional nanomaterials, and also demonstrates its use as a feasible power source that not only drives small electronics, but also scavenges energy from human actions.

Fabrication of multifunctional microfibrous and nanofibrous cellulose carriers and comparison of cell adhesion and spreading potential on them

Fibrous biomaterials have received much attention in tissue engineering and regenerative medicine due to their morphology, resembling extracellular matrix. In comparison to synthetic fibers, cellulose based fibers have interesting properties for cellular applications such as biodegradability, biocompatibility, simple preparation and their potential for chemical modification. Among cellulose derivatives, carboxymethyl cellulose and quaternized cellulose are the most important and valuable cellulose ethers which have anionic and cationic surface charge. In this research, we report the fabrication of multifunctional cellulose microfibrous and nanofibrous scaffolds and the comparison of adhesion and spreading potential of human fibroblast cell on them. The fabricated fibrous scaffolds were characterized by several instrumental techniques. The results showed that multifunctional cellulose nanofibers and microfiber had 8.6 and 8.2 mV surface potential, 7.1 and 6.8 MPa tensile strength, 560 and 510 MPa Young modules, 610 and 595% water uptake and 41o and 44o contact angle, respectively. The MTT assay showed that proliferation of fibroblast cells was enhanced in nanofibrous, compared to microfibrous mat. The SEM analysis of fixed cells on scaffolds showed that cells spreading on nanofibrous samples became more noticeable than microfibrous ones.

Multifunctional Cellulose Nanocrystals as a High-Efficient Polysulfide Stopper for Practical Li-S Batteries.

Because of the severe shuttle effect of polysulfides, achieving durable Li-S batteries is still a great challenge, especially under practical operation conditions including the high sulfur content, high loading, and high operation temperature. Herein, for the first time, low-cost, eco-friendly, and hydrophilic cellulose nanocrystals (CNCs) are proposed as a multifunctional polysulfide stopper for Li-S batteries with high performance. CNCs display an intrinsically high aspect ratio and a large surface area and contain a large amount of hydroxyl groups offering a facile platform for chemical interactions. Density functional theory calculations suggest that the electron-rich functional groups on CNCs deliver robust binding energies with polysulfides. In this work, CNCs not only firmly confine sulfur and polysulfides in the cathode as a robust binder, but also further hinder polysulfide shuttling to the Li anode as a polysulfide stopper on a separator. Consequently, the as-prepared Li-S batteries demonstrate outstanding cycling performance even under the conditions of high sulfur content of 90 wt % (63 wt % in the cathode), high loading of 8.5 mg cm-2, and high temperature of 60 °C. These results sufficiently demonstrate that CNCs have significant application potential in Li-S battery technologies.

Multifunctional cellulose nanocrystal structural colored film with good flexibility and water-resistance

Chiral nematic cellulose nanocrystal (CNC) structural colored materials are the focus of extensive research in recent years on account of their unique helical structure and excellent optical properties. However, the general weak mechanical properties and poor water-resistance of CNC limit its utility. Here, we fabricated highly flexible, water-resistant chiral nematic CNC/Poly(ethylene glycol) diacrylate(PEGDA) composite films, which was realized by co-assembling CNC and PEGDA precursor then via UV curing to construct a three-dimensional crosslinking network. Due to the water stimulus-responsive feature of the CNC and PEGDA, the CNC/PEGDA (8/2) composite film could be used as a water-content detector, photonic paper. In addition, it could produce different crosslinking degrees by coating the PEGMA solution or not, which could be applied to an anti-counterfeit label. The composite film with excellent stability of cycles is expected to be a promising candidate in optical sensors, display, and security fields.

Multifunctional cellulose nanocrystal /metal oxide hybrid, photo-degradation, antibacterial and larvicidal activities

Cellulose nanocrystal (CNC) and ZnO/CuO nanostructure were successfully synthesized by acid hydrolysis and sol-chemical methods, respectively. For the first time, CNC was used as a host polymer for synthesis of CNC/ZnO/CuO through In-situ solution casting technique. Morphological and structural of CNC, ZnO/CuO and hybrid CNC/ZnO/CuO were investigated by TEM, SEM-EDX, FT-IR, XRD and XPS analyses. The analysis revealed that, poly-dispersed, smooth and rod like CNC with an average length of ∼ 85.4 nm, average diameter of ∼13.9 nm and surface charge of 0.01 mmol/gm. As well, irregular shapes as hexagonal, spherical and cluster or star like of ZnO/CuO were formed. EDX and XRD spectra exhibited highly purified CNC/ZnO/CuO and pointed to cellulose II crystallite form with a monoclinic structure. The results demonstrated that, 91.3 % and 99.7 % dye degradation was achieved after 40 min of irradiation due to ZnO/CuO and CNC/ZnO/CuO treatment. Moreover, the inhibition zones formed due to 100 ppm ZnO/CuO were duplicated after integrating CNC (from 7.7:10.3 mm to 14.3:20.3 mm). The hybrid nanostructure exhibit larvicidal activity against Anopheles stephensi better than CNC and ZnO/CuO nanostructures.

Multifunctional UV-shielding nanocellulose films modified with halloysite nanotubes-zinc oxide nanohybrid

The design and fabrication of multifunctional UV-shielding materials based on naturally abundant and biodegradable raw materials have far-reaching significance for various practical applications and sustainable development. In the present work, novel multifunctional cellulose nanofibrils (CNFs)/halloysite nanotubes-zinc oxide (HNTs-ZnO) hybrid films with synergic feature of excellent UV-shielding, superhydrophobic properties and thermal stability were firstly fabricated via vacuum-assisted filtration strategy and following hydrophobic modification. The successful immobilization of ZnO nano-protrusions on HNTs surface effectively suppressed the aggregation of ZnO nanoparticles, giving a positive contribution for the UV-shielding performance. Particularly, the CNFs/HNTs-ZnO hybrid films achieved a high UV-blocking efficiency in both UVA (95.7%), UVB (98.7%) and UVC (99.8%). Besides, the filtration membrane template endowed the CNFs/HNTs-ZnO hybrid films with hierarchical rough architecture, and as-fabricated hybrid films presented superhydrophobicity with a contact angle over 155° and simultaneous self-cleaning function. Moreover, the CNFs/HNTs-ZnO hybrid films also displayed an outstanding thermal and UV stability. The findings conceivably indicate that the CNFs/HNTs-ZnO hybrid films provide a versatile way for the development of sustainable multifunctional UV-shielding films and have promising applications in packaging, intelligent windows and other outdoor UV-sensitive materials areas.

Fabrication and evaluation of carboxymethylated diethylaminoethyl cellulose microcarriers as support for cellular applications

Cellulose based microcarriers can be used in biomedical science as supports for cell adhesion and proliferation. However, to facilitate cell attachment to their surface, they require appropriate functional surface charge. Cell function such as adhesion and growth is increased on the modified surfaces with cationic and anionic groups. In this research, diethylaminoethyl cellulose was carboxymethylated to produce soluble multifunctional cellulose with simultaneous presence of cationic and anionic functional groups. Then, carboxymethylated diethylaminoethyl cellulose (CM-DEAEC) were produced by ionic crosslinking. Various instrumental techniques were applied to characterize the microcarriers. Biological tests were also performed to determine cell seeding efficiency, proliferation and attachment on microcarriers. Fabricated CM-DEAEC microcarriers had 1500–1800 μm diameter, +26.0 surface potential, 376% swelling behavior and 233 °C glass transition temperature respectively. The findings showed that CM-DEAEC microcarriers support cellular attachment and proliferation very well and hence are promising materials for cell therapy and tissue engineering applications.

Natural Biodegradable Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Nanocomposites with Multifunctional Cellulose Nanocrystals/Graphene Oxide Hybrids for High-Performance Food Packaging.

High-performance and useful graphene oxide (GO) and cellulose nanocrystals (CNCs) are easily extracted from natural graphite and cellulose raw materials, and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is produced by bacterial fermentation from natural plant corn stalks, etc. In this study, novel ternary nanocomposites consisting of PHBV/cellulose nanocrystal-graphene oxide nanohybrids were prepared via a simple solution casting method. The synergistic effect of CNC with GO nanohybrids obtained by chemical grafting (CNC-GO, covalent bonds) and physical blending (CNC/GO, noncovalent bonds) on the physicochemical properties of PHBV nanocomposites was evaluated and the results compared with a single component nanofiller (CNC or GO) in binary nanocomposites. More interestingly, ternary nanocomposites displayed the highest thermal stability and mechanical properties. Compared to neat PHBV, the tensile strength and elongation to break increased by 170.2 and 52.1%, respectively, and maximum degradation temperature (Tmax) increment by 26.3 °C, were observed for the ternary nanocomposite with 1 wt % covalent bonded CNC-GO. Compared to neat PHBV, binary, and 1:0.5 wt % noncovalent CNC/GO based nanocomposites, the ternary nanocomposites with 1 wt % covalent bonded CNC-GO exhibited excellent barrier properties, good antibacterial activity (antibacterial ratio of 100.0%), reduced barrier properties, and lower migration level for both food simulants. Such a synergistic effect yielded high-performance ternary nanocomposites with great potential for bioactive food packaging materials.

Functionalized cellulose with multiple binding sites for a palladium complex catalyst: synthesis and catalyst evaluation in Suzuki–Miyaura reactions

Due to their eco-friendly nature, polysaccharides are desirable supporting materials in organic transformations. Nevertheless, as is the case for other supports, polysaccharides have to face the issue of seeking more binding sites via multifunctional structures to capture metal species in the catalyst, which enhance stability and promote catalytic performance in aforementioned process. In this paper, an environmentally-friendly and multifunctional cellulose supported Pd(II)-Schiff base complex is fabricated and applied in the formation of different biaryls under mild ambient conditions. The results of thermal analysis reveal that the composite has high thermal stability. The as-prepared catalyst demonstrates to be a robust and efficient catalyst with more than 90% yields in H2O: EtOH (1:1) at 70 °C by using 0.30 mol% of catalyst under air towards the coupling of various substituted aryl halides and phenylboronic acids. Moreover, identified by ICP-OES analysis, the green Pd(II) catalyst displays higher metal content (1.93%) in comparison with the direct deposition of Pd particles on cellulose (0.93%), and prevents the metal leaching (< 1%) via the coordination interaction of multiple capturing sites (–OH, Schiff base and pyridyl moieties) with palladium. The resultant catalyst is characterized by FT-IR, TGA, XRD, SEM, TEM, XPS, CP/MAS 13C-NMR, and ICP-OES examination. Also, this green catalyst is able to be retrieved in five cycles with simple centrifugation. Notably, we propose a plausible multifunctional catalyst complex. The present study offers a novel and effective supported catalyst, which broadens the contributions of polysaccharides in green catalysis.

Multifunctional Cellulose Ester Containing Hindered Phenol Groups with Free-Radical-Scavenging and UV-Resistant Activities.

Excessive radicals and UV irradiation can trigger oxidative and physiological stresses, which cause tissue aging, human disease, food spoilage, and material degradation. In this study, a multifunctional cellulose ester containing hindered phenol groups, cellulose 3,5-di- tert-butyl-4-hydroxybenzoate (CBH), with free-radical-scavenging and UV-resistant activities was synthesized and used as a functional material. The obtained CBHs can effectively scavenge reactive nitrogen free radicals and hydroxyl free radicals in both solid and solution states. Moreover, CBHs have no cytotoxicity, and, on the contrary, they promote the proliferation of human epidermal keratinocytes. Benefiting from excellent solubility, processability, and formability, CBHs have been readily processed into flexible films, transparent coatings, and nanoribbons membranes. The highly transparent and flexible CBH film completely absorbs the light of 200-300 nm range and partially absorbs the light of 300-400 nm range, indicating a UV-shielding capability. After the CBHs were loaded on an ordinary facial mask by electrospinning or added into a hand cream, the resultant facial mask and hand cream exhibited outstanding free-radical-scavenging properties. In addition, CBHs can also be used to fabricate functional sprays with antioxidative and UV-shielding activities. Accordingly, the obtained CBHs have a huge potential in cosmetics, personal care products, biopharmaceuticals, papermaking, and art protection because of their excellent antioxidation, nontoxicity, UV resistance, formability, and odorless properties.

Multi-functional regenerated cellulose fibers decorated with plasmonic Au nanoparticles for colorimetry and SERS assays

Multi-functional cellulose fiber-Au composites were fabricated through a simple and cost-effective procedure by decorating regenerated cellulose fibers with Au nanoparticles. The cellulose fibers were regenerated from waste paper through the Ioncell-F process, an environmental friendly approach. After grafting positive charge, the surface of the cellulose fibers were decorated with citrate-stabilized plasmonic Au nanoparticles (NPs). X-ray photoelectron spectroscopy, scanning electron microscopy, X-ray diffraction, and optical images were used to characterize the regenerated cellulose fibers and fiber-Au NP composites. The fiber-Au composites exhibited different colors as the localized surface plasmon resonance property of Au NPs, which enables visual sensing of the water content in the fiber-Au composites through a colorimetric method. Furthermore, the regenerated cellulose fiber-Au composite was used as an enhanced substrate for the sensing of malachite green via surface-enhanced Raman scattering, in which the limit of detection was lower than 10 ppb. The multi-functional cellulose fibers are potentially suitable for the detection of toxins and the monitoring of water quality.

Three-dimensional cellulose based silver-functionalized ZnO nanocomposite with controlled geometry: Synthesis, characterization and properties

Cellulose based Ag-functionalized ZnO nanocomposite (AZC) films were prepared using a green and easy scale-up strategy. Firstly, ZnO embedded cellulose (ZC) nanocomposite was synthesized from a cellulose-NaOH/zincate/urea solution through a biomimetic approach. Secondly, Ag nanoparticles (NPs) with a mean diameter of 53.2 nm were efficiently deposited onto the surface of embedded ZnO in cellulose matrix under UV irradiation (16 w), yielding the multi-hybrid AZC film. Owing to the porous structure of cellulose substrate and its rich hydroxyl group, the NPs in the ACZ films displayed good stability. Because of the formation of Schottky barriers in the Ag-ZnO regions, the catalytic activity of ACZ films increased by 20 times when compared to that of ZC sample. Furthermore, the AZC films could completely inhibit both S. aureus and E. coli growth. This facile and eco-friendly approach is expected to pave the way for constructing multifunctional cellulose material for various niche applications.

A General Aqueous Silanization Protocol to Introduce Vinyl, Mercapto or Azido Functionalities onto Cellulose Fibers and Nanocelluloses.

The effective and straight-forward modification of nanostructured celluloses under aqueous conditions or as “never-dried” materials is challenging. We report a silanization protocol in water using catalytic amounts of hydrogen chloride and then sodium hydroxide in a two-step protocol. The acidic step hydrolyzes the alkoxysilane to obtain water-soluble silanols and the subsequent addition of catalytic amounts of NaOH induces a covalent reaction between cellulose surficial hydroxyl groups and the respective silanols. The developed protocol enables the incorporation of vinyl, thiol, and azido groups onto cellulose fibers and cellulose nanofibrils. In contrast to conventional methods, no curing or solvent-exchange is necessary, thereby the functionalized celluloses remain never-dried, and no agglomeration or hornification occurs in the process. The successful modification was proven by solid state NMR, ATR-IR, and EDX spectroscopy. In addition, the covalent nature of this bonding was shown by gel permeation chromatography of polyethylene glycol grafted nanofibrils. By varying the amount of silane agents or the reaction time, the silane loading could be tuned up to an amount of 1.2 mmol/g. Multifunctional materials were obtained either by prior carboxymethylation and subsequent silanization; or by simultaneously incorporating both vinyl and azido groups. The protocol reported here is an easy, general, and straight-forward avenue for introduction of anchor groups onto the surface of never-dried celluloses, ready for click chemistry post-modification, to obtain multifunctional cellulose substrates for high-value applications.

Fabrication of functional magnetic cellulose nanocomposite membranes for controlled adsorption of protein

Cellulose nanocomposite membranes with predesigned functions were prepared and evaluated as adsorbents for protein adsorption. Maghemite nanoparticles (MNP) with amino groups and carboxyl groups were obtained by modifying maghemite nanoparticles with glycine and sodium citrate, respectively. The functional maghemite nanoparticles were then dispersed into NaOH/urea aqueous solution for dissolving cellulose, and the magnetic membranes were constructed using a tape casting method. The modified MNP were evaluated by zeta potential and FTIR measurements. The developed cellulose nanocomposite membranes possess microporous structure with porosity higher than 88.3%. The introduction of MNP with carboxyl groups into the cellulose nanocomposite membranes could absorb the highest amount of protein at a pH of 4, and gradually decreased with the increase of pH from 4 to 6. However, cellulose nanocomposite membranes with introduced MNP with amino groups absorb the highest and lowest amount of protein at pH of 5 and 4, respectively. This study provides a green and simple method for the design of multifunctional cellulose nanocomposite membranes for controllable protein adsorption, and is expected to open new venues for biomolecule binding by choice of various nanofillers and pH of the medium.

Naked Au nanoparticles monodispersed onto multifunctional cellulose nanocrystal–graphene hybrid sheets: towards efficient and sustainable heterogeneous catalysts

A synthesis method has been developed for deposition of ∼3 nm monodisperse gold nanoparticles onto cellulose nanocrystal–graphene hybrid sheets.

Decorating silver nanoparticles on electrospun cellulose nanofibers through a facile method by dopamine and ultraviolet irradiation

In this paper, a new method is introduced for producing multi-functional cellulose nanofibers in order to achieve the biodegradable materials for various applications with a minimal amount of potentially toxic materials. Cellulose nanofibers (CNFs) were fabricated by electrospinning cellulose acetate solution followed by deacetylation. The CNFs were then treated with silver nitrate, ammonia, and sodium hydroxide and subsequently with dopamine as reducing and adhesive agent. Ag ions on the CNF surface were photo-reduced to Ag nanoparticles (NPs) using UVA irradiation to produce a dense layer of silver nanoparticles on the nanofibers. This is based on the simultaneous formation of polydopamine and Ag NPs on CNFs. Overall, this is a fast, simple, and efficient procedure that takes place in a conventional method at ambient temperature. The crystalline structure of CNFs decorated with AgNPs was studied by X-ray diffraction. Field-emission scanning electron microscopy and energy-dispersive X-ray patterns showed uniform distribution of silver nanoparticles on the CNF surface. Incorporation of AgNPs on the CNF surface via dopamine improved the electrical conductivity and also the tensile strength of the nanomat. The CNFs decorated with AgNPs exhibited a low electrical resistivity around 35 KΩ/square and a tensile strength of 87% higher than untreated CNFs.

Fluorescent Multifunctional Polysaccharides for Sustainable Supramolecular Functionalization of Fibers in Water

The paper describes the synthesis of multifunctional cellulose derivatives (MCDs) containing a fluorescent and a cationic moiety and their application in the functionalization of pulp fibers. The cellulose derivatives, namely N-(3-propanoic acid)- and N-(4-butanoic acid)-1,8-naphthalimide esters of cellulose, differed in the degree of substitution (DS) and by the aliphatic chain connecting naphthalimide photoactive groups to the polymer backbone. The derivatives were decorated with a cationic moiety, namely (3-carboxypropyl)trimethylammonium chloride. The fluorescent pulp fibers were prepared by direct self-assembly of the water-soluble fluorescent MCDs on the fibers in water at room temperature. The results indicated that the adsorption was mainly driven by an ion exchange mechanism. UV–vis and fluorescence spectroscopic studies showed that the adsorption yield of the fluorescent MCDs depended on the length of the aliphatic chain of the photoactive groups. Because of the adsorption, the modified pulp fib...

Layer-by-layer structured polysaccharides-based multilayers on cellulose acetate membrane: Towards better hemocompatibility, antibacterial and antioxidant activities

The development of multifunctional cellulose acetate (CA) membranes with enhanced hemocompatibility and antibacterial and antioxidant activities is extremely important for biomedical applications. In this work, significant improvements in hemocompatibility and antibacterial and antioxidant activities of cellulose acetate (CA) membranes were achieved via layer-by-layer (LBL) deposition of chitosan (CS) and water-soluble heparin-mimicking polysaccharides (i.e., sulfated Cantharellus cibarius polysaccharides, SCP) onto their surface. The surface chemical compositions, growth manner, surface morphologies, and wetting ability of CS/SCP multilayer-modified CA membranes were characterized, respectively. The systematical evaluation of hemocompatibility revealed that CS/SCP multilayer-modified CA membranes significantly improved blood compatibility including resistance to non-specific protein adsorption, suppression of platelet adhesion and activation, prolongation of coagulation times, inhibition of complement activation, as well as reduction in blood hemolysis. Meanwhile, CS/SCP multilayer-modified CA membranes exhibited strong growth inhibition against Escherichia coli and Staphylococcus aureus, as well as high scavenging abilities against superoxide and hydroxyl radicals. In summary, the CS/SCP multilayers could confer CA membranes with integrated hemocompatibility and antibacterial and antioxidant activities, which might have great potential application in the biomedical field.

Multifunctional cellulose esters by olefin cross-metathesis and thiol-Michael addition

Post-cross-metathesis thiol-Michael addition affords functionally diverse cellulose esters.

Fabrication of multifunctional cellulose nanocrystals/poly(lactic acid) nanocomposites with silver nanoparticles by spraying method

The poly (lactic acid) (PLA)/functionalized cellulose nanocrystals formates (CNFs) were prepared by solution casting and then the binary films were sprayed with silver ammonia aqueous solution to fabricate PLA/CNF/Ag ternary nanocomposites. It was found that both deposited silver (Ag) nanoparticles and CNFs showed efficient reinforcing effect on the thermal, mechanical, barrier properties and antibacterial activity of PLA matrix. Especially, the maximum decomposition temperature (Tmax) and Young's modulus of PLA/CNF/Ag(6) nanocomposite film increased by 15.5°C and 48.7%, respectively. Meanwhile an obvious reduction in the water vapor permeability was detected. Furthermore, the migration levels of the ternary nanocomposite films were well below the permitted limits in both non-polar and polar food simulants (60mgkg−1), and they showed a significant antibacterial activity influenced by the Ag contents. This study reveals that the novel nanocomposite films will offer a good perspective for food packaging applications.