Cellulose Nanoparticles Research Articles

Preparation of Gentamicin Conjugated Cellulose Nanocrystals and Evaluation of Efficacy on Different Microorganisms

Large amounts of waste cotton material generated in textile production cause environmental problems and resource depletion. The production of nanocrystalline cellulose is one of the effective way to the recycling of waste cotton. Cellulose nanoparticles are of great interest in biomedical applications due to their various properties. In this study cellulose nanocrystals were produced from waste cotton through acid hydrolysis in a single step. The extraction of cellulose from waste cotton was carried out by alkalin treatment, afterthat the cellulose nanocrystals were isolated by the nitric acid (68% w/w) and hydrochloride acid (37% w/w) mixture acid hydrolysis. Cellulose nanocrystals were oxidized by sodium periodate (NaIO4) for functionalization. The prepared cellulose nanocrystals were characterized by Transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) then gentamicin conjugation studies were carried out. Gentamicin conjugated cellulose nanoparticles were examined for antimicrobial activity against Escherichia coli (E. coli), Staphylococcus aureus (S. Aureus), Pseudomonas aeruginosa(aeruginosa), Klebsiella pneumoniae (K. pneumoniae) and antifungal activity against Candida albicans (C. Albicans). The results confirmed that the periodate oxidized cellulose nanocrystals are effective on bacterai and fungus.

High-resolution study of garlic and agave cellulose nanoparticles crystalline structures using transmission electron microscopy (TEM)

High-resolution study of garlic and agave cellulose nanoparticles crystalline structures using transmission electron microscopy (TEM)

Spherical Cellulose Micro and Nanoparticles: A Review of Recent Developments and Applications.

Cellulose, the most abundant natural polymer, is a versatile polysaccharide that is being exploited to manufacture innovative blends, composites, and hybrid materials in the form of membranes, films, coatings, hydrogels, and foams, as well as particles at the micro and nano scales. The application fields of cellulose micro and nanoparticles run the gamut from medicine, biology, and environment to electronics and energy. In fact, the number of studies dealing with sphere-shaped micro and nanoparticles based exclusively on cellulose (or its derivatives) or cellulose in combination with other molecules and macromolecules has been steadily increasing in the last five years. Hence, there is a clear need for an up-to-date narrative that gathers the latest advances on this research topic. So, the aim of this review is to portray some of the most recent and relevant developments on the use of cellulose to produce spherical micro- and nano-sized particles. An attempt was made to illustrate the present state of affairs in terms of the go-to strategies (e.g., emulsification processes, nanoprecipitation, microfluidics, and other assembly approaches) for the generation of sphere-shaped particles of cellulose and derivatives thereof. A concise description of the application fields of these cellulose-based spherical micro and nanoparticles is also presented.

Solubility analysis of nano particles, cellulose crystalline region and cellulose molecule, and the impact study of crystalline region on properties of cellulose insulating paper

ABSTRACT For the first time, molecular dynamics simulation was used to analyse the solubility of five kinds of nanoparticles (SiO2, ZnO, Al2O3, Fe2O3, TiO2), cellulose crystalline region and cellulose molecules in this paper. The results show that the solubility of cellulose nanoparticles is positively related to the number of –OH groups on the surface of nanoparticles. The solubility between nano particles and cellulose molecules is smaller than that between cellulose crystalline region and cellulose molecules, which leads to the direct introduction of nano particles for physical modification reducing the solubility parameters of insulating paper. Through the analysis of mechanical properties, thermal stability and insulation properties, it is concluded that the comprehensive performance of the model with 70% crystalline region ratio is the best. The proportion of crystalline region further increased, the improvement of thermal stability is not obvious; the relative permittivity and the content of crystalline region are in line with the binomial fitting curve, and the constant term in the fitting curve is the relative permittivity of the amorphous region model; increasing the proportion of crystalline region is beneficial to improve the insulation performance of cellulose insulation paper.

Preparation and applications of chitosan and cellulose composite materials

Chitosan is a natural fiber, chemically cellulose-like biopolymer, which is processed from chitin. Its use as a natural polymer is getting more attention because it is non-toxic, renewable, and biocompatible. However, its poor mechanical and thermal strength, particle size, and surface area restrict its industrial use. Consequently, to improve these properties, cellulose and/or inorganic nanoparticles have been used. This review discusses the recent progress of chitosan and cellulose composite materials, their preparation, and their applications in different industrial sectors. It also discusses the modification of chitosan and cellulose composite materials to allow their use on a large scale. Finally, the recent development of chitosan composite materials for drug delivery, food packaging, protective coatings, and wastewater treatment are discussed. The challenges and perspectives for future research are also considered. This review suggests that chitosan and cellulose nano-composite are promising, low-cost products for environmental remediation involving a simple production process.

Analisis Pengaruh Perlakuan Microwave Plasma dalam Cairan Terhadap Kadar Glukosa dan Produk Nano Material Pada Ampas Tebu

Sugarcane (Saccharum officinarum L.) is a raw material that is processed to produce crystal sugar and bioethanol. The process produces sugarcane bagasse. In this study, The liquid-plasma treatment based on microwave plasma in the liquid was used to treat sugarcane bagasse to observe the effect on glucose concentration and gain byproducts. The energy input parameters were varied by 340, 360, and 400 W with irradiation time variations of 1, 3, and 5 minutes. Nelson Somogyi's method was used to determine the percentage of glucose as well as Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscope (SEM), and Image-J software to characterize the side-product of the samples. The results showed that the glucose concentration reduced around 27.6% - 99.2 % after microwave plasma in-liquid treatment at the energy input of 340 Watt and 360 Watt, respectively, with an irradiation time of 5 minutes. The side-product is cellulose nanoparticles which have an average diameter of 92, 106, and 169 nm

An ethyl cellulose-based supramolecular gel composite coating for metal corrosion protection and its self-healing property from electromagnetic heating effect

The barrier coating is the most important and effective method for corrosion protection. However, inevitable defects of various scales from micro to macro on coatings due to mechanical damage, aging, corrosive medium penetration, etc. will lead to coating failure. Usually, the damaged coating can only be removed and then recoated. At present, most of coatings are disposable coating and can not be recycled or healing repeatedly. In this paper, a supramolecular gel composite coating was prepared with ethyl cellulose, castor oil, mineral oil, and Fe3O4 nanoparticle, which are bonded together by hydrogen bonds and Van Der Waals forces. This coating could be multiple healed in situ by an alternating magnetic field based on the electromagnetic heating effect of Fe3O4 particles. The SEM/EDS results indicating that the best content of Fe3O4 in coating is 10% for good dispersion. Under an alternating magnetic field, the composite coating can be uniformly heated through hysteresis loss, and starts to heal when the temperature of the composite coating reaches 80 °C. After self-healing process, the mechanical properties and corrosion resistance of the composite coating have almost no difference with the original intact coating. Since the supramolecular gel is bonded by hydrogen bonding and Van Der Waals forces, these bonds are opened when heated and recombined after cooling without any change of properties. Therefore, the microstructure of supramolecular gel composite coating has no significant change and the corrosion protection performance has not decreased after 10 times of healing.

Precise Measurements of the Temperature Influence on the Complex Permittivity of Power Transformers Moistened Paper-Oil Insulation

The reference characteristics of complex permittivity of the transformers insulation solid component were determined for use in the precise diagnostics of the power transformers insulation state. The solid component is a composite of cellulose, insulating oil and water nanoparticles. Measurements were made in the frequency range from 10−4 Hz to 5000 Hz at temperatures from 293.15 to 333.15 K. Uncertainty of temperature measurements was less than ±0.01 K. Pressboard impregnated with insulating oil with a water content of (5.0 ± 0.2) by weight moistened in a manner maximally similar to the moistening process in power transformers was investigated. It was found that there are two stages of changes in permittivity and imaginary permittivity components, occurring for low and high frequency. As the temperature increases, the frequency dependencies of the permittivity and imaginary permittivity component shifts to the higher frequency region. This phenomenon is related to the change of relaxation time with the increase in temperature. The values of relaxation time activation energies of the permittivity ΔWτε′ ≈ (0.827 ± 0.0094) eV and the imaginary permittivity component ΔWτε″ = 0.883 eV were determined. It was found that Cole-Cole charts for the first stage are asymmetric and similar to those described by the Dawidson–Cole relaxation. For stage two, the charts are arc-shaped, corresponding to the Cole-Cole relaxation. It has been established that in the moistened pressboard impregnated with insulating oil, there is an additional polarization mechanism associated with the occurrence of water in the form of nanodrops and the tunneling of electrons between them.

A novel method for producing cellulose nanoparticles and their possible application as thickeners for biodegradable low-temperature greases

A novel method for producing cellulose nanoparticles and their possible application as thickeners for biodegradable low-temperature greases

NANOCELLULOSE FROM REED STALKS TO IMPROVE THE PROPERTIES OF PAPER FOR PACKAGING FOOD PRODUCTS

Background. The development of technologies for obtaining materials from plant raw materials, the use of which improves the consumer properties of cardboard and paper products and does not pollute the environment with harmful substances from synthetic polymers, is an urgent problem of our time. Objective. The purpose of the paper is to obtain pulp and nanocellulose from reed stalks by environmentally friendly methods and apply nanocellulose to improve the quality parameters of paper for packaging food products on automatic machines. Methods. To obtain pulp from reed stalks with a minimum residual content of lignin and minerals, two processing stages were used: alkaline extraction and organosolv cooking at a temperature of 97 ± 2 °C. Nanocellulose was obtained by the oxidation of organosolv reed pulp with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) in the TEMPO / NaBr / NaClO system, which is more environmentally friendly than acid hydrolysis. The resulting nanocellulose was applied to paper samples from waste paper and sulphate unbleached pulp at a consumption from 1 to 3 g/m2. Results. Organosolv pulp was obtained from reed stalks with a residual lignin content of 0.53 % and an ash content of 0.045 %, which was used to obtain nanocellulose. The resulting nanocellulose particles have a transverse size in the range of 5–20 nm, a length of up to several micrometers, and the tensile strength of nanocellulose films is up to 60 MPa. It is shown that the application of nanocellulose to the surface of the samples increases the breaking strength and breaking length, and reduces the surface absorbency of paper. It was determined that with a nanocellulose consumption of up to 3 g/m2, paper samples have indicators that meet the requirements of the standard for paper for packaging food products on automatic machines. Conclusions. The use of nanocellulose from reed stalks as a hardening substance for paper production will allow replacing environmentally harmful polymer additives and up to 50 % of more expensive softwood pulp with waste paper, while maintaining paper quality indicators at the level of standard requirements.

Ultrasonic-mediated production of carboxylated cellulose nanospheres

In this study, carboxy-functionalized spherical cellulose nanoparticles have been produced from Alfa plant-derived cellulose microfibers (CMF) using ultrasonic-induced cellulose fragmentation process. CMF, with fiber diameter of 7.26 µm and crystallinity of 87%, were firstly produced from Alfa plant fibers and then subjected to surface carboxylation using TEMPO-mediated oxidation process. The as-resulted TEMPO-oxidized CMF (T-CMF), with an average diameter of 2.72 µm, a crystallinity of 89% and carboxyl groups content of 1032 mmol COO-/Kg cellulose, were then exposed to ultrasonication treatment for 45 min, resulting in the formation of cellulose nanospheres (CNS) with an average diameter of 33.96 ± 7.01 nm and a crystallinity of 76%. The carboxyl groups content on the surface of CNS was measured at 945 mmol COO-/Kg cellulose. This study demonstrated the importance of the ultrasonication process as a green method for producing CNS with interesting properties, which can be used in various potential functional applications.

Modulating the controlled release of hydroxychloroquine mobilized on pectin films through film-forming pH and incorporation of nanocellulose

Materials from renewable resources like pectin and nanocelluloses are useful for the controlled release of drugs such as hydroxychloroquine (HCQ), whose potential for treating tumor cells was recently verified. In this study, pectin films with HCQ were produced by casting at different pH values (4, 7, and 10). Additionally, pectin/HCQ membranes formed at pH 4 were incorporated with cellulose nanocrystals (CNC) and nanofibrils (CNF). Films are mainly amorphous with good compatibility between HCQ and pectin matrix. Release tests showed that films containing CNC and formed at pH 4 released the drug more slowly in phosphate buffer medium compared to other membranes. Additionally, film formed at pH 4 presented slower HCQ release at acid medium. The pectin platform proved to be an easy way to deliver HCQ with different kinetic rates by changing the pH and incorporating nanocellulose particles into the pectin film-forming solutions.

Multifunctional 3D cationic starch/nanofibrillated cellulose/silver nanoparticles nanocomposite cryogel: Synthesis, adsorption, and antibacterial characteristics

We report a new 3D nanocomposite cryogel combines the advantages of cationic starch (Cs), nanofibrillated cellulose (NFC) and silver nanoparticles (Ag NPs). Cs was the main component of the cryogel while NFC was used as a filling agent to enhance the mechanical properties of the produced cryogel. Both Cs and NFC endow the cryogel with adsorption properties while Ag NPs enhances its antibacterial properties. Ag NPs was green synthesized with the aid of microwave radiation using NFC as reducing and stabilizing agent. The prepared Ag particles were free of impurities with sizes <10 nm and good stability in solution. Two different concentrations of the prepared Ag NPs were added to a mixture of Cs and NFC and subjected to freeze drying to get porous cryogel (3D microstructure). The Ag NPs free cryogel has highly porosity smooth surface with large surface area. Adding Ag NPs decreased these features and increased the 3D roughness. Optimum adsorption of reactive blue 49 was observed after 30 min of contact with 1.5 g/L of the cryogel at pH 1. The adsorption kinetics and isotherm were best described by the pseudo-first-order and Freundlich equations, respectively. All prepared cryogels have notable antibacterial properties that were significantly improved by adding Ag NPs. Overall, the new 3D composite cryogel can efficiently remove dyes and bacteria from wastewater.

Preparation of Cellulose Nanoparticles from Foliage by Bio-Enzyme Methods

There are vast reserves of foliage in nature, which is an inexhaustible precious resource. In this study, the chemical components of five foliage types (pine needles, black locust tree leaves, bamboo leaves, elm leaves and poplar leaves) were analyzed, including cellulose content, hemicellulose content, and lignin content. The bio-enzymatic method was then used to prepare cellulose nanoparticles (CNPs) from these five kinds of leaves, and the prepared CNPs were analyzed using TEM, FTIR, FESEM, and XRD. The results showed that the content of hemicellulose in bamboo leaves was the highest, and the lignin content in the other four leaves was the highest. The cellulose content in the five kinds of foliage was arranged from large to small as pine needles (20.5%), bamboo leaves (19.5%), black locust leaves (18.0%), elm leaves (17.6%), and poplar leaves (15.5%). TEM images showed that the CNPs prepared by the five kinds of foliage reached the nanometer level in width and the micrometer level in length; therefore, the CNPs prepared in this study belonged to cellulose nanofibers (CNFs). The results of FTIR and XRD showed that CNFs prepared by the enzyme treatment exhibited a typical crystalline structure of cellulose II. The degree of crystallinity (DOC) of CNFs prepared from pine needle, poplar leaves, and bamboo leaves are 78.46%, 77.39%, and 81.51%, respectively. FESEM results showed that the CNFs prepared from pine needles, poplar leaves and bamboo leaves by enzymatic method presents a three-dimensional (3D) network structure, and their widths are 31 nm, 36 nm, and 37 nm, respectively. This study provides a meaningful reference for broadening the use of foliage types and improving their added value.

Electrostatic-triggered exothermic antibody adsorption to the cellulose nanoparticles

Antibody-conjugated nanoparticles are used in a fields ranging from medicine to engineering. NanoAct® nanobeads are cellulose nanoparticles used in lateral flow assays that are highly water dispersible. In order to promote the adsorption of antibodies onto NanoAct® particles while maintaining their activity, we analyzed the adsorption onto NanoAct® particles thermodynamically and elucidated the adsorption mechanism. In an immunochromatographic assay, the amount of adsorbed antibody and the color intensity of the test line increased as the pH decreased. The zeta potential of the nanoparticles remained constant at around −30 mV over the pH range from 2 to 10. The model antibody had pI values between 6.2 and 6.8. Isothermal calorimetry analysis showed that adsorption of antibody to the NanoAct® particle is an endothermic reaction under low pH conditions, an exothermic reaction between pH 6 and pH 7, and a weakly exothermic reaction above pH 7. These data indicate that the changes in net charge of the antibody surface as a function of pH influence the pH dependence of antibody adsorption to the negatively charged NanoAct®. This suggests that increased positive charge on the antibody surface will result in a more sensitive NanoAct®-based immunoassay.

Integrating polyacrylonitrile (PAN) nanoparticles with porous bacterial cellulose hydrogel to produce activated carbon electrodes for electric double-layer capacitors

Activated carbons, BC-PANnp-ACs and BC-PANnp-KACs, have been synthesized from a composite (BC-PANnp) derived from bacterial cellulose (BC) and polyacrylonitrile nanoparticles (PANnp) by physical and chemical activation, respectively. Commercially available nata de coco has been used as the source of BC whereas PAN nanoparticles of ca. 100 nm have been synthesized in situ in the BC gel by emulsion polymerization which covers the nanofibers of BC. FE-SEM images confirm that hierarchical lamellar structure of BC is retained in the activated carbon frameworks. Detailed electrochemical studies carried out with the electrodes designed with the activated carbons reveal their good performance as electric double layer capacitors (EDLC) with fast response and high-speed charging and discharging. The activated carbons prepared by KOH activation have much higher specific surface area and exhibit better electrochemical properties compared to the carbon materials obtained by CO2 activation or the commercially available YP50F activated carbon derived from coconut shell. The three-dimensional network structure peculiar to BC reduces the grain boundary resistance between the carbonized PAN nanoparticles in these composites compared to PAN nanoparticles carbonized alone imparting good conductivity without the addition of a conductive agent.

Simultaneous Effect of Ultrasonic and Chemical Treatment on the Extraction of Nanocellulose From Sugarcane Bagasse

The focus of this study was the simultaneous effect of ultrasonic and chemical treatment on the extraction of nanocellulose from sugarcane bagasse. Ultrasonic waves can accelerate the dispersion process of nanocellulose particles so that extraction runs faster and is environmentally friendly. The bagasse was treated by chemical treatment with ultrasonic waves, and then the nanocellulose was prepared using acid hydrolysis with ultrasonic waves. The effect of ultrasonication was investigated. The crystallinity of sugarcane bagasse, cellulose, and nanocellulose was analyzed by X-ray diffraction. Based on the diffractogram, there was an increase in the crystallinity of nanocellulose. The chemical composition of extracted cellulose and nanocellulose was analyzed by Fourier-transformed infrared spectroscopy. The results of the analysis showed that lignin and hemicellulose were removed from the bagasse during the extraction process. The analysis results also showed that the breaking of intramolecular hydrogen and glycosidic bonds occurred during the hydrolysis process. The morphology of bagasse, cellulose, and nanocellulose was analyzed by Scanning electron microscopy. While the particle size of nanocellulose was analyzed by the Particle Size Analysis instrument. The average size of nanocellulose particles was 132.67 nm.

Bioaccessibility and intracellular antioxidant activity of phloretin embodied by gliadin/sodium carboxymethyl cellulose nanoparticles

In this work, gliadin/sodium carboxymethyl cellulose nanoparticles (G/CMC) were prepared to encapsulate bioactive phloretin (Phl) for improving the stability and bioaccessibility by simple antisolvent precipitation. Scanning electron microscopy (SEM) and dynamic light scattering showed that G/CMC nanoparticles were spherical with the diameter below 350 nm. Electrostatic interaction and hydrogen bond were dominant driving force during the formation of G/CMC nanoparticles. Phloretin-loaded G/CMC nanoparticles (G/CMC-Phl) had robust resistance to pH shift, heat treatment and UV irradiation. The bioaccessibility of encapsulated phloretin increased from 23% to 55% via the strategy, as compared with free phloretin. Meanwhile, G/CMC-Phl had a strongly protective effect on erythrocyte hemolysis induced by 2, 2′-azobis-2-methyl-propanimidamide dihydrochloride (AAPH), and inhibited the generation of reactive oxygen species (ROS). It could recover the intracellular antioxidant enzymes (superoxide dismutase, SOD and glutathione peroxidase, GSH-Px) activity to normal levels and inhibit the production of malondialdehyde (MDA). Moreover, the protection and control release behavior of G/CMC nanoparticles was investigated by B16 mouse melanoma cells. This study provides a simple way to fabricate food-grade nanoparticles for the encapsulation of water-insoluble phloretin to broaden the application in pharmaceutical, cosmetics and food industry.

Solvent Free Synthesis of the Carboxymethyl Cellulose/Polyaniline Silver nanoparticles Composite thin Films

Flexible polymer composite films comprising carboxymethyl cellulose (CMC), polyaniline (PANI) and silver nanoparticles (AgNps) were successfully fabricated through an in-situ polymerization method. The composite structure of the fabricated film was confirmed by X-ray diffraction and infrared spectroscopy, indicating the successful incorporation of AgNps into the CMC/PANI blend. The scanning electron microscope (SEM) images have indicated a homogenous loading and dispersion of AgNps into the CMC/PANI blend. The optical parameters such as band gap (Eg) was determined using the UV optical absorbance. The inclusion of AgNps and PANI has enhanced the optical properties of the CMC polymer, providing a new composite suitable for energy conversion systems, solar cells, biosensors, and nonlinear optical applications. The electrical properties of the composites were examined using temperature-dependent DC conductivity within 293–373 oK. The composites with increasing AgNps in the PANI-CMC composites shows the enhancement in the higher crystallinity, thermal stability, and higher electrical conductivity. the antimicrobial properties were evaluated with the aid of agar diffusion tests. The results showed distinct zones of inhibition against major microorganisms.

Detection of nanoplastics based on surface-enhanced Raman scattering with silver nanowire arrays on regenerated cellulose films

Plastic pollution has steadily become a global issue due to its ubiquity and degradation into micro and nanoparticles. Herein, we report the construction of surface-enhanced Raman scattering (SERS)-active array substrates with regenerated cellulose (RC) and plasmonic nanoparticles (AuNRs and AgNWs) via a simple vacuum-assisted filtration method using a silicon mask for rapid nanoplastic detection. The AgNWs/RC film exhibited a SERS intensity of crystal violet approximately six times higher than that of the AuNRs/RC film with a high enhancement factor of 1.8 × 107. Moreover, the AgNWs/RC film exhibits a better SERS activity for polystyrene nanoplastic detection than the AuNRs/RC film because the dense AgNW network structures are well suited for nanoplastic detection. The AgNWs/RC film can detect PS nanoplastics down to 0.1 mg/mL with a good reproducibility of the SERS signal. The low-cost, flexible, and highly sensitive AgNWs/RC films could provide an efficient and rapid SERS-based method for nanoplastic detection.