Cellulose Nanoparticles Research Articles

Functionalization and Antibacterial Applications of Cellulose-Based Composite Hydrogels.

Pathogens, especially drug-resistant pathogens caused by the abuse of antibiotics, have become a major threat to human health and public health safety. The exploitation and application of new antibacterial agents is extremely urgent. As a natural biopolymer, cellulose has recently attracted much attention due to its excellent hydrophilicity, economy, biocompatibility, and biodegradability. In particular, the preparation of cellulose-based hydrogels with excellent structure and properties from cellulose and its derivatives has received increasing attention thanks to the existence of abundant hydrophilic functional groups (such as hydroxyl, carboxy, and aldehyde groups) within cellulose and its derivatives. The cellulose-based hydrogels have broad application prospects in antibacterial-related biomedical fields. The latest advances of preparation and antibacterial application of cellulose-based hydrogels has been reviewed, with a focus on the antibacterial applications of composite hydrogels formed from cellulose and metal nanoparticles; metal oxide nanoparticles; antibiotics; polymers; and plant extracts. In addition, the antibacterial mechanism and antibacterial characteristics of different cellulose-based antibacterial hydrogels were also summarized. Furthermore, the prospects and challenges of cellulose-based antibacterial hydrogels in biomedical applications were also discussed.

Nanocellulose in Heterogeneous Water-Based Polymerization for Wood Adhesives

The interest in the development of biobased adhesives has increased due to environmental concerns. Moreover, as the production of engineered wood products (EWPs) is expected to grow, the wood adhesives market needs to transit toward formaldehyde-free products. Cellulose nanoparticles (CNPs) are a material with unique properties and advantages for producing hybrid materials as biobased wood adhesives. Besides their traditional use as reinforcing additives, CNPs can be incorporated at the beginning of the polymerization reaction to form in situ polymerized hybrid adhesives with better mechanical and physicochemical properties than the neat adhesive. Despite their outstanding characteristics, CNPs are still an emerging nanomaterial in the wood adhesive field, and the studies are incipient. This review explores the utilization of CNPs in heterogeneous polymerization for the production of polyvinyl acetate, polymeric isocyanates, waterborne polyurethane systems, and other waterborne polymer latexes. The main challenges are discussed, and some recommendations are set down for the manufacture of these novel hybrid nanocomposites.

Investigation of Polycaprolactone/Carboxymethyl Cellulose Scaffolds by Mechanical and Thermal Analysis

The objective of this work was to learn more about three-dimensional porous scaffolds made from biomaterial based on polycaprolactone (PCL) containing different amounts of carboxymethyl cellulose (CMC) nanoparticles. Composite material samples containing 0, 2, 6.5, 11, 15.5, and 20% w/w of CMC and PCL/CMC scaffolds were prepared with the use of the salt particle leached technique. The mechanical properties were evaluated with the compressive strength analysis method. The studied temperature range started at very low temperatures and ended at crosslinking temperatures. It was evaluated using the thermal analysis methods of Differential Scanning Calorimetry (DSC) in the range 0ºC-200ºC. The results revealed that the compressive modulus of blended PCL/CMC scaffold was higher than the one of pure PCL scaffold (582.2±106.2 kPa for pure PCL scaffold and 612.2±296 kPa for blended scaffold which contained 20% of CMC). For DSC analysis, in addition to the 15.5% w/w CMC PCL/CMC composite scaffold, other proportions of composite materials showed a decrease in crystallization temperature. The crystallinity of PCL-20% CMC was higher than that of PCL scaffolds.

Ethyl cellulose nanoparticles as stabilizers for Pickering emulsions

Pickering emulsions stabilized by ethyl cellulose nanoparticles have recently received –great attention for their remarkable stability and numerous industrial applications. De- spite this, the exact stabilization mechanism of such Pickering emulsions is still not fully understood. Both the stabilization of the emulsion by particle adsorption at the inter- face and through network formation in the continuous phase (leading to a yield stress) have been suggested. In this work we study soybean oil-in-water emulsions stabilized by ethyl cellulose nanoparticles and find, by the use of confocal microscopy and interfa- cial tension measurements, that the main stabilization mechanism of this nanoparticle- stabilized emulsions is the adsorption of the particles at the interface, instead of forming a network in the continuous phase. At the same time, oscillatory rheology measurements reveal that the emulsions exhibit a yield stress well below the random close-packing limit for hard spheres, suggesting short-range interactions between the droplets caused by the presence of the particles at the interface. The presence of the particles at the interface in combination with the observed rheological behavior of an attractive emulsion gives a strong indication for a particle-bridged stabilized emulsions.

DEVELOPMENT OF NANO BASED FILM FORMING GEL FOR PROLONGED DERMAL DELIVERY OF LULICONAZOLE

Objective: Luliconazole (LZL) has low aqueous solubility that limits its dermal bioavailability and acts as a barrier to topical delivery. The conventional topical formulations have a limited ability to retain the drug over the skin for a prolonged period. The main objective of the study was to formulate and characterize LZL loaded ethyl cellulose (EC) nanoparticles and formulate them as a film-forming gel (FFG) for prolonged delivery in fungal skin infections.Methods: The solvent evaporation technique was used for the preparation of nanoparticles of LZL by using EC as a polymer. The prepared nanoparticles were evaluated for physical appearance, production yield, entrapment efficiency, drug content, particle size, zeta potential, Polydispersity index (PDI), and in vitro drug release. Then the nanoparticles were incorporated into FFG formulation by using polyvinyl pyrrolidone (PVP) and polyvinyl alcohol (PVA) as the gelling agent. The prepared FFG was evaluated for pH, Viscosity, Spreadability, in vitro drug release studies, in vitro antifungal studies, and release kinetic studies.Results: The optimized nanoparticle formulation F5 having drug to polymer ratio of 1:2 showed satisfactory production yield (86.32%), entrapment efficiency (83.36%), drug content (42.86), particle size (125.3), and 93.72% of in vitro drug release after 24 h (h). The optimized FFG formulation FFG4 showed the shortest film-forming time of 5.06 min (min), percentage Cumulative drug release of 92.18% after 24 h, and had promising in vitro antifungal activity.Conclusion: The prepared FFG could be used with promising potential for fungal infection of the skin.

Synthesis and Physicochemical Properties of the Nanocomposites Based on Sodium Carboxymethyl Cellulose and Selenium Nanoparticles

Synthesis and Physicochemical Properties of the Nanocomposites Based on Sodium Carboxymethyl Cellulose and Selenium Nanoparticles

Molecular dynamics study of thermal properties of polyamide nanocomposites reinforced with natural biofillers

Bio-based fillers have been used for reinforcements in thermoplastic polymer, predominantly in the past decade, to improve its mechanical and thermal performance. This study has made use of Molecular Dynamics (MD) simulations using Large-scale Atomic/Molecular Massively Parallel Simulator package to investigate the thermal behavior of polyamide 6 nanocomposites when they are reinforced with natural biofillers such as starch, cellulose, and coconut shell nanoparticles. A comparative study is conducted to examine the degree of improvement or deterioration of thermal properties under the effect of respective nanofillers. Density, glass transition temperature (Tg), heat capacity, thermal diffusivity, and thermal conductivity were inspected with simulations run in a temperature range of 200–600 K. Glass transition temperature has been calculated from three parameters, by the dependence of density, dielectric constant, and electrostatic energy on temperature. Non-equilibrium MD simulations using Fourier's law method were followed to calculate thermal conductivity. This study has concentrated on thermal evaluations of bio-based polyamide nanocomposites helpful in determining the flame retardancy of the materials.

3D-printable chitosan/silk fibroin/cellulose nanoparticle scaffolds for bone regeneration via M2 macrophage polarization

Biopolymers-induced immune microenvironment exhibited prominent effects on bone regeneration. Osteo-immunomodulatory responses of cellulose nanoparticles incorporated chitosan hydrogel scaffolds have not yet been reported. The objective of this study was to monitor the synergistic effects of silk fibroin and cellulose nanoparticles on the immune-modulatory behavior of chitosan biopolymer scaffolds. 3D-printed biodegradable cellulose nanoparticles-reinforced chitosan/silk fibroin (CS/SF/CNPs) scaffolds were fabricated and characterized by different spectroscopic techniques. The improved rheological and recovery strength was observed in CS/SF/CNPs hydrogels than pure polymer hydrogels. A significant shift from M1 → M2 macrophages polarization occurred in the CS/SF/CNPs scaffolds treated groups than the control after 3 days of incubation, showing its immune-modulatory potential. Osteo-immunomodulatory effects of the fabricated scaffolds were analyzed on human bone marrow-derived mesenchymal stem cells (hBMSCs), with macrophages-derived conditioned media (M-CM). Enhanced bone regeneration was observed in the calvaria defect rat model, indicating that the fabricated scaffolds are promising materials for bone-healing applications.

Co-encapsulation of quercetin and resveratrol in zein/carboxymethyl cellulose nanoparticles: characterization, stability and in vitro digestion.

Oral administration of combinations of specific nutrients and nutraceuticals can provide synergistic health benefits to humans. In this work, zein/carboxymethyl cellulose composite nanoparticles were successfully prepared using antisolvent precipitation methods. Zein/carboxymethyl cellulose nanoparticles with the smallest size (204.6 nm) were formed when the mass ratio of zein to CMC was 2 : 1. Hydrogen bonding and hydrophobic interactions were dominant binding forces to stabilize the composite nanoparticles. Quercetin and resveratrol were then encapsulated within these nanocarriers, which improved their resistance to both light and thermal degradation. Encapsulation of the nutraceuticals was shown to delay their release under simulated gastrointestinal conditions, which may be beneficial for some applications. Moreover, encapsulation increased the in vitro bioaccessibility of the quercetin and resveratrol. Our results indicate that zein/carboxymethyl cellulose nanoparticles can be used to co-deliver combinations of bioactive compounds, which may be useful for the development of functional foods, supplements, and pharmaceuticals.

Highly antibacterial hydrogels prepared from amino cellulose, dialdehyde xylan, and Ag nanoparticles by a green reduction method

Highly antibacterial hydrogels prepared from amino cellulose, dialdehyde xylan, and Ag nanoparticles by a green reduction method

Removal of U(vi) from aqueous solutions by an effective bio-adsorbent from walnut shell and cellulose composite-stabilized iron sulfide nanoparticles.

FeS nanoparticles were easily aggregated and oxidized in the natural environment. It was important to stabilize the iron sulfide nanoparticle composite with a stabilizer. Biochar could be used as an effective carrier to inhibit the agglomeration and oxidization of FeS nanoparticles. An efficient and novel bio-adsorbent (CFeS-WS) from walnut shell (WS) and cellulose composites-stabilized iron sulfide nanoparticle was synthesized by the modified method. The removal of U(vi) ions from an aqueous solution by CFeS-WS was carried out. The experimental results indicated that numerous functional groups were observed on the surface of CFeS-WS. In addition, the biochar was loaded successfully with cellulose and FeS nanoparticle composites. The cellulose and biochar effectively prevented the agglomeration of FeS nanoparticles. The adsorption process of U(vi) ions by CFeS-WS was more consistent with the pseudo second-order kinetic model and Langmuir isotherm model. The adsorption process of U(vi) ions was an endothermic and chemical reaction process. The proposed reaction mechanism of the U(vi) ion removal by CFeS-WS mainly consisted of the ion exchange reaction, reduction reaction, hydrogen bonding and functional group, and pore of the adsorbent filling. According to the results of the recycle experiment, it indicated that the chemical stability of CFeS-WS was good.

Tailoring a bio-based adsorbent for sequestration of late transition and rare earth elements.

The demand for new renewable energy sources, improved energy storage and exhaust-free transportation requires the use of large quantities of rare earth (REE) and late transition (LTM, group 8-12) elements. In order to achieve sustainability in their use, an efficient green recycling technology is required. Here, an approach, a synthetic route and an evaluation of the designed bio-based material are reported. Cotton-derived nano cellulose particles were functionalized with a polyamino ligand, tris(2-aminoethyl) amine (TAEA), achieving ligand content of up to ca. 0.8 mmol g-1. The morphology and structure of the produced adsorbent were revealed by PXRD, SEM-EDS, AFM and FTIR techniques. The adsorption capacity and kinetics of REE and LTM were investigated by conductometric photometric titrations, revealing quick uptake, high adsorption capacity and pronounced selectivity for LTM compared to REE. Molecular insights into the mode of action of the adsorbent were obtained via the investigation of the molecular structure of the Ni(II)-TAEA complex by an X-ray single crystal study. The bio-based adsorbent nanomaterial demonstrated in this work opens up a perspective for tailoring specific adsorbents in the sequestration of REE and LTM for their sustainable recycling.

Sustainable decoloration of polluted water through cellulosic TiO2 nano- crystalline material composite using sono synthesis

Titanium dioxide (TiO2) nanomaterials are noteworthy for their valuable photoactive properties and applications. Their cellulosic nano-particles could be used for the decoloration of polluted water since they are eco-friendly. Therefore, this study investigated the cellulose powder coated with a layer of nano-crystalline-titanium dioxide (TiO2) through the sonosynthesis process to minimize the hazardous of contaminated water containing reactive dyes. Powder X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Zeta Potential Spectroscopy were utilized to examine the subsequent composition. Decoloration of the compositions was perceived through Ultra Violet (UV) light at 30 min. It was observed that the composition simultaneously improved the quality (cleaning) of polluted water. It absorbed the reactive dye hastily in 2 min which is the fastest time reported up to now and transformed the polluted water quality into hygienic condition. Additionally, the cleaning efficiency of the polluted water was increased with the number of functional repeats. Thus, assisted in an eco-friendly remedy of wastewater and minimizing the pollution.

Strategy Towards Active Food Packaging Material From Cellulose Nanoparticles and its Characterization

The utilization of agro-industrial wastes such as sugarcane bagasse (SCB) as a source of cellulose has influenced a wide range of interest in various applications such as food packaging, drug delivery, paper production, etc. Owing to the rich source of cellulose in SCB, the nanoparticle was prepared efficiently. The pure form of cellulose was isolated from SCB by eliminating the remaining components such as hemicellulose and lignin by treating SCB with a soluble base and a bleaching agent. Cellulose nanoparticles were synthesized from the purified cellulose by acid hydrolysis using H2SO4 followed by dialysis to remove sulfate ions and attain neutrality. The obtained nanoparticles were characterized using FTIR spectroscopy that helped to confirm the exclusion of lignin and hemicellulose. The crystalline nature of the cellulose nanoparticles (CNPs) was confirmed using X-Ray Diffraction (XRD). The morphology of CNPs was studied by scanning electron microscopy (SEM), and the particle size of CNPs was found to be 189 nm by particle size analysis (PSA). Further, this study proved the nanomaterial preparation from agro-wastes can be utilized to develop food packaging film in food industries.

Magnetic dispersive solid phase extraction based on carbonized cellulose–ferromagnetic nanocomposite for screening phthalate esters in aqueous samples

In this work, a sorbent of the carbonized cellulose–ferromagnetic nanocomposite has been proposed for the magnetic dispersive solid phase extraction of some plasticizers in aqueous samples. Carbonized cellulose nanoparticles were prepared by treatment of cellulose filter paper with concentrated sulfuric acid and then loaded on Fe3O4 nanoparticles using coprecipitation. This sorbent is compatible with aqueous samples and can be considered as a viable sorbent for extraction of plasticizers from aqueous samples. In this study, magnetic dispersive solid phase extraction is followed by a dispersive liquid–liquid microextraction method. This combination makes the proposed approach as an efficient clean–up method with high enrichment factors for the selected analytes. The enriched analytes are monitored by gas chromatography equipped with a flame ionization detector. Parameters affecting the method efficiency were investigated in details. Under the optimized extraction conditions, limits of detection could reach up to of 0.15–0.50 µg L−1. The satisfactory enrichment factors of 286–403 were obtained, and the extraction recoveries were found to be in the range of 57–80%. Relative standard deviations were in the range of 3–7% for intra–day and inter–day precisions for six replicate extractions at 25 µg L−1 of each plasticizer. Calibration curves were linear in wide ranges with coefficients of determination ≥ 0.995. Eventually, efficiency of the prepared sorbent was confirmed by the extraction of some plasticizers from real samples including fruit juices, mineral water, injection solution, cola, and yoghourt drink packed in plastic containers.

Highly efficient detection of chloramphenicol in water using Ag and TiO2 nanoparticles modified laser-induced graphene electrode

Chloramphenicol (CAP) is a typical broad-spectrum antibiotic, which is still frequently detected in various water environments. In this work, a novel electrochemical sensor was developed to detect CAP in water environment by loading TiO2 modified with sodium carboxymethyl cellulose (CMC) and silver nanoparticles (AgNPs) onto the laser-induced graphene (LIG). The Ag/CMC@TiO2/LIG electrode was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and contact angle (CA) analysis. The mechanism of the enhancement of electrochemical signal is that the dispersion of CMC promotes the synergistic catalysis of AgNPs and TiO2NPs. The electrochemical properties of the Ag/CMC@TiO2/LIG electrode were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The Ag/CMC@TiO2/ LIG electrode shows a low CAP detection limit of 0.007 μM and a linear response in the range of 0.01 to 100 μM. The sensor has been successfully applied to the detection of CAP in tap water and lake water with recoveries of 93.60% to 105.70% and relative standard deviations of less than 2.08%. These results provide new insights on using carbon based electrochemical sensor for rapid detection of CAP in water environment.

High dielectric flexible thin films based on cellulose nanofibers and zinc sulfide nanoparticles

Nanocomposites have become potential candidate materials for integration into high-frequency electronics. In the current work, ZnS nanocomposite films were successfully prepared from cellulose nanofibers (CNF) - isolated from bagasse pulp- with different weight ratios of ZnS nanoparticles (ZnS NPs). The structure was characterized by infrared and ultraviolet–visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM)/ Energy dispersive X-ray spectroscopy (EDX). Infrared spectroscopy proved the presence of interactions between cellulose and ZnS nanoparticles. The SEM and EDX analysis showed that ZnS nanoparticles were well dispersed in the cellulose matrix. Band gap width of Zn/CNF nanocomposites film calculated from UV–Vis spectra was 2.64 eV which is lower than pure CNF (4.5 eV). Electrical properties were investigated within the frequency range of 100 Hz−5 MHz, and temperature range of 25–120 °C. DC- electrical conductivity was investigated and the activation energy Ea was estimated from the Arrhenius relation. The effect of wt. % of ZnS nanoparticles on electrical properties as dielectric constant, and ac-electrical conductivity (σac) were studied. The results showed that the all ZnS/CNF nanocomposite thin films had semiconductor properties and the 5 wt% ZnS NP sample had the highest conductivity value. The results indicate that the prepared flexible ZnS/ CNF nanocomposites thin films are promising candidates for semiconductor materials used in electronic devices.

Cellulose-Silver Composites Materials: Preparation and Applications.

Cellulose has received great attention owing to its distinctive structural features, exciting physico−chemical properties, and varied applications. The combination of cellulose and silver nanoparticles currently allows to fabricate different promising functional nanocomposites with unique properties. The current work offers a wide and accurate overview of the preparation methods of cellulose–silver nanocomposite materials, also providing a punctual discussion of their potential applications in different fields (i.e., wound dressing, high-performance textiles, electronics, catalysis, sensing, antimicrobial filtering, and packaging). In particular, different preparation methods of cellulose/silver nanocomposites based on in situ thermal reduction, blending and dip-coating, or additive manufacturing techniques were thoroughly described. Hence, the correlations among the structure and physico–chemical properties in cellulose/silver nanocomposites were investigated in order to better control the final properties of the nanocomposites and analyze the key points and limitations of the current manufacturing approaches.

Rheological and Tribological Properties of Nanocellulose-Based Ecolubricants.

Based on the response surface methodology, a rheological and tribological study carried out on eco-friendly lubricants is described. Such ecolubricants consisted of fibrillated or crystalline nanocellulose in vegetable oil (castor oil, high oleic sunflower oil or their mixtures). Cellulose nanoparticles showed noticeable friction-reducing and anti-wear properties within the boundary and mixed lubrication regimes, which were found to be dependent on nanocellulose concentration, base oil composition and applied normal force. In general, both types of nanocellulose performed equally well. An excellent tribological performance, with large wear scar diameter reductions, was achieved with 3.3 wt.% (or higher) nanocellulose dispersions in castor oil-rich mixtures. The observed behavior was explained on the basis of enhanced viscosity of castor oil-rich suspensions and the preferential action of the most polar components, nanocellulose and ricinoleic acid, in the vicinity of the contact surfaces.

Synthesis of Composite from Bacterial Cellulose and Gold Nanoparticles

A process of bacterial cellulose gold nanocomposite has been investigated based on experimental work and cited literature. A literature review on the production process is carried out in this study. Bacterial cellulose is a high crystalline fabric material generally used in biomedical applications. A Nanocomposite was made by synthesis from gold and bacterial cellulose. The experimental work includes growing, and isolating bacterial cellulose, preparation of gold Nanoparticles and preparation of Nano composite. Nanoparticle’s formation and adsorption on the cellulose tissue have been observed visually, where a colour change was observed. The predicted particle size for the gold nanoparticles was (2-100) nm.