Thermal and mechanical properties of chitosan nanocomposites with cellulose modified in ionic liquids

In this paper, ionic liquid treatment was applied to produce nanometric cellulose particles of two polymorphic forms. A complex characterization of nanofillers including wide-angle X-ray scattering, Fourier transform infrared spectroscopy, and particle size determination was performed. The evaluated ionic liquid treatment was effective in terms of nanocrystalline cellulose production, leaving chemical and supermolecular structure of the materials intact. However, nanocrystalline cellulose II was found to be more prone to ionic liquid hydrolysis leading to formation larger amount of small particles. Each nanocrystalline cellulose was subsequently mixed with a solution of chitosan, so that composite films containing 1, 3, and 5% mass/mass of nanometric filler were obtained. Reference samples of chitosan and chitosan with micrometric celluloses were also solvent casted. Thermal, mechanical, and morphological properties of films were tested and correlated with properties of filler used. The results of both, tensile tests and thermogravimetric analysis showed a significant discrepancy between composites filled with nanocrystalline cellulose I and nanocrystalline cellulose II

A novel enzymatic approach to nanocrystalline cellulose preparation

In this work, conditions for an enzymatic pretreatment prior to NCC isolation from cotton linter were assessed. Different cellulase doses and reaction times were studied within an experimental design and NCC were obtained. At optimal enzymatic conditions (20U, 2 h), a total yield greater than 80% was achieved and the necessary enzymatic treatment time was reduced 90%. Different intensities of enzymatic treatments led to proportional decreases in fiber length and viscosity and also were inversely proportional to the amount of released oligosaccharides. These differences within fibers lead to quantitative differences in NCC: increase in acid hydrolysis yield, reduction of NCC surface charge and crystallinity increase. Benefits produced by enzymatic treatments did not have influence over other NCC characteristics such as their sulfur content (˜1%), size (˜200 nm), zeta potential (˜-50 mV) or degree of polymerization (˜200). Evidence presented in this work would reduce the use of harsh sulfuric acid generating a cleaner stream of profitable oligosaccharidesPostprint (author's final draft

Rheological properties of cellulose nanocrystal-embedded polymer composites: a review

Nanotechnology provides useful insights into the behavioural properties of materials from the nanoscale point of view, enabling researchers to develop new materials that were previously inconceivable. Cellulose is an ideal candidate for nanomaterial for nanotechnology because of its nanofibrillar structure, abundance, renewability, biodegradability and eco-friendly nature. Nanocrystalline cellulose materials have become the focus many studies related to these materials and their applications. This review summarises the current knowledge on the field of nanomaterials, focussing mainly on the rheological behaviour of polymer nanocomposites embedded with nanocrystalline cellulose. This review will enable better understanding of the use of nanocrystalline cellulose for the development and applications of cellulose nanocrystal-based nanocomposites

Review on nanocrystalline cellulose in bone tissue engineering applications

Nanocrystalline cellulose is an abundant and inexhaustible organic material on Earth. It can be derived from many lignocellulosic plants and also from agricultural residues. They endowed exceptional physicochemical properties, which have promoted their intensive exploration in biomedical application, especially for tissue engineering scaffolds. Nanocrystalline cellulose has been acknowledged due to its low toxicity and low ecotoxicological risks towards living cells. To explore this field, this review provides an overview of nanocrystalline cellulose in designing materials of bone scaffolds. An introduction to nanocrystalline cellulose and its isolation method of acid hydrolysis are discussed following by the application of nanocrystalline cellulose in bone tissue engineering scaffolds. This review also provides comprehensive knowledge and highlights the contribution of nanocrystalline cellulose in terms of mechanical properties, biocompatibility and biodegradability of bone tissue engineering scaffolds. Lastly, the challenges for future scaffold development using nanocrystalline cellulose are also included

Manufacturing of nanocrystalline cellulose

Nanocrystalline cellulose (CNC) has attracted considerable attention over the last several decades in many fields. Sulfuric acid hydrolysis is utilized as the state-of-the-art for producing nanocrystalline cellulose nowadays. The common conditions of H2SO4 standard method used 1 735% of acid dosage, 64% of acid concentration, 45oC of temperature and 45 minutes of reaction time. The purpose of this thesis is to develop and determine a novel modified manufacturing method for CNC production process by adjusting the reaction circumstances. More precisely, this study investigates the possibility for using lower acid amount and higher temperature (65oC-85oC) to produce nanocrystalline cellulose. The raw material in the production procedures was microcrystalline cellulose (MCC). CNCs were extracted from MCC by sulfuric acid. Various reaction conditions (acid dosage, temperature, acid concentration, reaction time) were changed based on the performance of CNC yield and quality in order to obtain the optimal circumstances. The morphology and dimensions of CNCs were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The chemical structure and crystallinity were measured by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Thermogravimetric analysis (TGA) was utilized to study the thermal stability of CNCs. The results from the characterization methods demonstrated that using lower sulfuric acid dosage and higher temperature could also produce CNCs with promising yield and qualities as standard method. The optimal hydrolysis conditions for modified method are described as follow: 700% of acid dosage, 65oC of temperature, 63% of acid concentration and 20 minutes of reaction time. Based on the modified method, CNCs could have a maximum yield of 30.6% of and crystallinity of 79.3%. The average length of CNCs could be 183.1nm and the mean diameter was 7.6nm. The preliminary economy analysis illustrated that applying modified method provided better economy than the existing standard method

Optimization of Biocomposite Film Based on Whey Protein Isolate and Nanocrystalline Cellulose from Pineapple Crown Leaf Using Response Surface Methodology

This study employed response surface methodology to optimize the preparation of biocomposites based on whey protein isolate, glycerol, and nanocrystalline cellulose from pineapple crown leaf. The effects of different concentrations of nanocrystalline cellulose as a filler and glycerol as a plasticizer on the thickness, the tensile strength, and the elongation at break on the resulting biocomposite films were investigated. The central composite design was used to determine the optimum preparation conditions for biocomposite films with optimum properties. The regression of a second-order polynomial model resulted in an optimum composition consisting of 4% glycerol and 3.5% nanocrystalline cellulose concentrations, which showed a desirability of 92.7%. The prediction of the regression model was validated by characterizing the biocomposite film prepared based on the optimum composition, at which the thickness, tensile strength, and elongation at break of the biocomposite film were 0.13 mm, 7.16 MPa, and 39.10%, respectively. This optimum composition can be obtained in range concentrations of glycerol (4–8%) and nanocrystalline cellulose (3–7%). Scanning electron microscope images showed that nanocrystalline cellulose dispersed well in the pure whey protein isolate, and the films had a relatively smooth surface. In comparison, a rough and uneven surface results in more porous biocomposite films. Fourier transform infrared spectroscopy revealed that nanocrystalline cellulose and glycerol showed good compatibility with WPI film by forming hydrogen bonds. The addition of nanocrystalline cellulose as a filler also decreased the transparency, solubility, and water vapor permeability and increased the crystallinity index of the resulting biocomposite film

The Effect of Nano Crystalline Cellulose-Filled to Tensile Strength of Oil Palm Trunk Starch-Based Adhesive

Has conducted research on the effect of nanocrystals of cellulose produced from oil palm trunk. Nano crystalline cellulose-field into the oil palm trunk starch modified. There was a increase in the quality of oil palm trunk starch which be used to as adhesives. Their modified starch added DSTB. Nano crystalline cellulose produced by oil palm empty fruit bunches used isolation method. Adhesive  characterized by tensile strength, and SEM. Durability and adhesion strength of the nanocomposites were compared to those of the Indonesian Standard for wood adhesives which there have been gave us a new information for adhesive. Nanocrystalline cellulose added 2% into nanocomposite were the optimal yield. Keywords: modified-starch, nanocrystalline cellulose, tensile strength, and SE

PENGARUH AGING PADA KEKUATAN TARIK (TENSILE STRENGTH) FILM LATEKS KARET ALAM BERPENGISI NANOKRISTALIN SELULOSA DAN PENYERASI ALKANOLAMIDA

Nanocrystalline cellulose is nano sized filler with high crystallinity and obtanained by hydrolysis of alpha cellulose from sugarcane bagasse. Tensile test of natural rubber latex film filled nanocrystalline cellulose and alkanolamide as compatibilizer after aging treatment have been done. Natural rubber latex films were prepared by coagulant dipping method and followed by vulcanization process at temperature 100 oC and 20 minutes. Aging treatment of natural rubber latex films have done at temperature 70 oC for 24 hours. Tensile test result of natural rubber latex filled nanocrystalline cellulose showed the tensile strength value of aged natural rubber latex film were lower than unaged one. However, tensile strength value of aged natural rubber latex film filled nanocrystalline cellulose modified alkanolamide were higher than unaged film

The Effect of Nanocrystalline Cellulose (NCC) Filler on Polylactic Acid (PLA) Nanocomposite Properties

This paper discusses the effect of nanocrystalline cellulose (NCC) when used as filler on polylactic acid (PLA)-based nanocomposites and on its mechanical properties and permeability. NCC was produced from commercial cellulose and another cellulose source, i.e. oil palm empty fruit bunch, by hydrolysis of microcrystalline cellulose with sulphuric acid and by oxidation with ammonium persulfate. The nanocomposites were made by adding nanocrystalline cellulose with varying compositions into PLA. A solvent casting method was used to produce a nanocomposite film with 5% v/v triacetin as a coupling agent. Both methods produced crystalline celluloses within the micro and nano range with mean particle size at 99.5 nm and 157.9 nm for the sulphuric acid hydrolysis and the ammonium persulfate oxidation method, respectively. The utilization of NCC as PLA composite filler increased the percentage of elongation at break with a highest percentage 19.02% for addition of 1% NCC filler. However, higher compositions of cellulosic filler resulted in a decreasing trend of tensile strength and elongation at break. Higher content of NCC filler in the PLA matrix increased the nanocomposite's water vapor permeability

Production, Processes and Modification of Nanocrystalline Cellulose from Agro-Waste: A Review

Nanocrystalline cellulose is a renewable nanomaterial that has gained huge attention for its use in various applications from advanced biomedical material to food packaging material due to its exceptional physical and biological properties, such as high crystallinity degree, large specific surface area, high aspect ratio, high thermal resistance, good mechanical properties, abundance of surface hydroxyl groups, low toxicity, biodegradability, and biocompatibility. However, they still have drawbacks: (1) sources of raw materials and its utilization in the production of nanocomposites and (2) high chemical and energy consumption regarding the isolation of macro-sized fibers to nano-sized fibers. The incorporation of hydrophilic nanocrystalline cellulose within hydrophobic polymer limits the dispersion of nano-sized fibers, thus resulting in low mechanical properties of nanocomposites. Hence, surface modification on nano-sized fiber could be a solution to this problem. This review focuses on the advanced developments in pretreatment, nanocrystalline production and modifications, and its application in food packaging, biomedical materials, pharmaceutical, substitution biomaterials, drug excipient, drug delivery automotive, and nanopaper applications