Cellulose Microcrystals Research Articles

Toward mechanical recyclability of high barrier food packaging films through filler incorporation on the EVOH layer

AbstractTo preserve food from moisture and oxygen, polymers, such as ethylene vinyl alcohol (EVOH) are used in multilayer structures to provide oxygen barrier, while low‐density polyethylene (LDPE) is used for a water vapor barrier. While this material combination is functionally ideal, it may not comply with the new packaging recycling guidelines. Some European markets have implemented rules that limit the weight percentage of EVOH in LDPE films. One way to increase recyclability is by reducing the amount of EVOH in the film structure while maintaining the packaging's oxygen barrier properties. To achieve this, it is necessary to improve the barrier properties of EVOH. With this objective in mind, this study evaluated the incorporation of nanoclays (NC), cellulose microcrystals (MCC), silicon dioxide nanoparticles (SiO2), and cellulose nanocrystals (CNC) into an EVOH matrix. The results indicate that NC and MCC facilitate a stable blown film extrusion process and have a better dispersion in the EVOH matrix. Based on this finding, three‐layer films (with an ABA configuration) consisting of LDPE (A) and EVOH (7 μm layer) with 0.5 or 1 wt.% MCC or NC (B) were produced to protect the EVOH from moisture and enable blown film processing. The oxygen transmission rate (OTR) values were lowest for 0.5 wt.% NC and 1 wt.% MCC incorporation. Although the films with micro and nanoparticles had increased haze, this did not affect the visibility of the packaged food.

The influence of cellulose microcrystals and nanofibrils in XSBR polymers on the mechanical properties of jute textile-reinforced cementitious composites

The influence of cellulose microcrystals and nanofibrils in XSBR polymers on the mechanical properties of jute textile-reinforced cementitious composites

The Effect of Microcrystal Cellulose Filling from Coconut Fiber and Betel Leaf Extract as Antimicrobials on Sago Starch Bioplastic Composite

Starch-derived bioplastics have weaker mechanical properties than conventional polymers and a short lifespan due to their susceptibility to microbial degradation. This study examines the impact of microcrystalline cellulose (MCC) and betel leaf extract on the characteristics of sago starch bioplastic composites. Microcrystalline cellulose extracted from coconut coir improves tensile strength, and betel leaf extract improves antibacterial properties. This study began by isolating alpha-cellulose from coconut coir and continued by isolating microcrystalline cellulose via the hydrolysis procedure employing hydrochloric acid. As an antibacterial, this research extracted betel leaf using 96% ethanol and a rotary evaporator. MCC variations of 0, 2, and 4(b) and betel leaf extract variations of 0, 3, and 6%(v) in 100 g of sago starch were examined. Up to 20% of the combination comprises glycerol as a plasticizer(v). MCC and betel leaf extract altered bioplastic composites’ properties. A bioplastic composite with 2% MCC and 6% betel leaf extract can inhibit the growth of Bacillus cereus bacteria. It has a tensile strength of 274,531 kPa, an elongation at break of 3.72%, a density of 0.724 g/cm3, and a water absorption of 7.79%. It concludes that MCC and betel leaf extract had an antibacterial effect in starch bioplastic composite.

Study on the microcrystal cellulose and the derived 2D graphene and relative carbon materials

Microcrystal cellulose (MCC) is a green and sustainable resource that widely exists in various lignocellulose species in percentage 10% to 30%. The fine powder of MCC is often discarded in industrial productions that use lignocellulose as feedstock. The crystal structure of two types of MCC (sugarcane pith and bamboo pith) and their derived carbon materials are studied, and the key findings are summarized as follows. (1) In the MCC refined from sugarcane pith, there are large amount of cellulose 2D crystal, which can be converted to valuable 2D graphene crystal. (2) In the MCC refined from bamboo pith there are large amount of cluster microcrystal cellulose, which can be converted to soft and elastic graphene microcrystal (GMC). (3) The 2D cellulose in MCC of sugarcane pith has large surface area and is easily to be degraded to sugars by acid–base hydrolysis reaction, which can be carbonized to Fullerenes-like carbon spheres. (4) The crystal structures of MCC derived carbon materials are strongly impacted by the crystal structures of MCC, and the carbonization reaction of MCC follows “in situ carbonization” and “nearby recombination” mechanism. In general, the results from this study may open a new way for value-added applications of microcrystal cellulose.

Performance of thermally conductive NR composites reinforced with stearic acid‐modified microcrystalline cellulose: A combined experimental and molecular dynamic simulation study

AbstractWith the increasing environmental requirements for improving products and materials using renewable and sustainable resources, cellulose has been seen as one of the most attractive and promising alternatives to traditional inorganic fillers. We developed a new modification method to improve the interface compatibility between natural rubber and sisal cellulose, to improve the mechanical and thermal conductivity properties of rubber composite. Microcrystalline cellulose (MCC) was extracted from sisal cellulose and then the hydrophobic cellulose (SA‐MCC) was prepared by grafting stearic acid on the surface of MCC. MCC and SA‐MCC were added to the thermal conductivity composite material composed of natural rubber and boron nitride. The results showed that the thermal conductivity and tensile properties of the natural rubber composites increased by 17.3% and 20%, respectively, under the addition of 1.8 wt% SA‐MCC. Furthermore, the interfacial interaction between the components in the composite was studied by molecular dynamics simulation. The solubility parameters, free volume fraction, and molecular binding energy were calculated to verify the effectiveness of the modification. This work is expected to provide a theoretical basis for the design and preparation of high‐performance natural rubber composite materials.Highlights Cellulose microcrystals were successfully extracted from sisal fiber and modified. Through the combination of boron nitride and the modified cellulose microcrystals, the thermal conductivity and tensile properties of thermal rubber were successfully improved synchronously. A reasonable molecular simulation model was established to analysis the strengthening mechanism from the microscopic point of view. The molecular simulation conclusions on interface enhancement are in good agreement with the experimental properties.

Synthesis and characterization of microcrystals cellulose from citronella waste (Cymbopogon nardus L.) as a filler in graphene oxide

One of the energy storage materials that is interesting to research is graphene-based. Electrodes from multiple layers of graphene oxide can produce dense porous materials capable of trapping charged ions of various sizes. Graphene-based materials generally need to be composited to prevent layer buildup, resulting in less than optimal energy storage characteristics. Microcrystal cellulose should be added to reduce the formation of the graphene layer and increase the pore size. Microcrystal cellulose are produced by decomposing and separating the parts of natural cellulose crystals. One type of grass in Bangka Belitung is the citronella (Cymbopogon nardus). The cellulose yield from citronella waste is 22%. Based on FTIR spectroscopy, there are typical functional groups of cellulose such as C=O, C-H, C-O, and C-O-C groups. The size of the cellulose microcrystals obtained is 49.47 µm.

Humidity‐Responsive Polyvinyl Alcohol/Microcrystalline Cellulose Composites with Shape Memory Features for Hair‐Styling Applications

AbstractThis study investigates the maintenance of humidity‐responsive shape memory polymer composites comprising polyvinyl alcohol (PVA) and cellulose microcrystal for maintaining hair curls in humid environments. The composite films are prepared by a simple blending method using aqueous solutions of different polymer ratios and characterized for thermal properties, chemical structure, and surface morphology. The hydroxyl groups in the PVA and cellulose provided hydrogen‐bonding interactions and improved the miscibility of the composites. Increasing the cellulose content in the composites enhanced mechanical properties and curl‐shape recovery performance, with 20–25 wt.% cellulose achieving maximum recovery. When the PVA/cellulose solution is applied to natural hair, it effectively maintains the shape of curled hair bundles for at least 6 h under 80% humidity and promotes the hair shape recovery rate to 8–10%. Overall, The proposed humidity‐responsive PVA/cellulose composites present promising application potential in the field of hairstyling to withstand humid weather.

Effect of quercetin addition on chitosan film composite of cellulose microcrystals from coconut fibers (Cocos Nucifera)

This study aimed to synthesize chitosan biodegradable films and cellulose microcrystals (CMC) from coconut fibres (Cocos nucifera) with quercetin as a filler. Chitosan (CS) film is mixed with cellulose microcrystals with a composition of 1% w/w, and quercetin bioflavonoids are added with various concentrations (0%;1%;3%;5%;7% w/w) by solution casting method. Adding quercetin to the chitosan-microcrystalline cellulose film is expected to add antioxidant properties. Cellulose microcrystals were isolated from the primary material of coconut fibres by delignification, bleaching which was then hydrolysis by 58% w/w sulfuric acid. Isolation results were characterized by FTIR, XRD and SEM. The results of research for the synthesis of chitosan-microcrystalline cellulose-quercetin films showed the addition of quercetin 7% resulted in tensile strength of 17.21 MPa, biodegradation rate of 1.62 mg/day, antioxidant activity of 79.95%. However, adding 7% quercetin decreases the nature of film development and water vapour permeability, with the optimum quercetin concentration for film development being 1% and water vapour permeability being 3%.

Insight into the physicochemical properties and thermal behavior of cellulose microcrystals isolated from Aleppo pine using different delignification approaches

Insight into the physicochemical properties and thermal behavior of cellulose microcrystals isolated from Aleppo pine using different delignification approaches

Investigation of the structural variations of cellulose microcrystals obtained after acid hydrolysis of waste cotton: a statistical approach

The intricate and complex network of inter- and intramolecular hydrogen bonds in cellulose exerts a significant influence on the overall crystallographic structure of the cellulose polymer. Hence, understanding the hydrogen bonding interactions during cellulose hydrolysis is vital for tailoring the degree of crystallinity of cellulose-based materials like cellulose microcrystals (CMCs). In this study, we used a Box–Behnken statistical tool to optimize the experimental parameters for synthesizing CMCs with a high total crystallinity index (TCI). We then used field emission scanning electron microscopy, X-ray photoelectron spectrometry, X-ray diffraction, and Fourier transform infrared spectroscopy to investigate the morphological, chemical, crystalline, and structural changes that occurred in the CMC sample with the highest TCI. Our results showed that the hydrolysis process modified the hydrogen bonding network in cellulose, which resulted in an enhanced TCI. The changes in hydrogen bonding significantly affected CH bending and stretching absorption, resulting in an increased TCI of the cellulose samples. This increased TCI plays a significant role in enhancing the reinforcing properties of CMCs. Our findings highlight new insights into the role of hydrogen bonding in the TCI of CMCs and could lead to the development of new methods for controlling the TCI of cellulose. Highlights of the article Optimization of the acid hydrolysis process of waste cotton using Box–Behnken design to obtain cellulose microcrystals (CMCs). Extraction of the mathematical model that influences the total crystallinity index of CMCs. Investigation of morphological, chemical, crystalline, and structural changes in CMCs. Comparison of hydrogen bonding network between waste cotton fibers and CMCs. Increased TCI enhances CMCs’ reinforcing properties in composites.

Biodegradation of various forms of cellulose and chitin in natural waters with different salinity

This study evaluated the ultimate aerobic biodegradability of cellulose and chitin samples in natural water. The as-prepared cellulose powder, microcrystals, and gel, together with the chitin microcrystals, were observed under an electron microscope and characterized using Fourier transform infrared spectroscopy, X-ray diffraction, and nitrogen-adsorption measurement techniques. The samples were then subjected to biochemical oxygen demand testing at 20 °C, in the dark, for 30 d, in fresh water, brackish water, and seawater collected from the Kamogawa River and Osaka Bay, Japan. The biodegradability of the cellulose and chitin samples was greater than that of the poly(ε-caprolactone) film used as a positive control sample and was in the order of chitin microcrystals > cellulose hydrogel ≈ cellulose microcrystals > cellulose powder. These results indicate that the higher the specific surface area, the higher the degree of degradation of the cellulose samples. Chitin microcrystals displayed a higher degree of degradation than cellulose microcrystals although both had near-identical specific surface areas, indicating that chitin is more easily degraded than cellulose in natural waters. The degree of degradation in natural water was in the order of fresh water > brackish water > seawater. This trend implies that the higher the salinity, the more the degradation was suppressed.

An eco-friendly method using deep eutectic solvents immobilized in a microcrystal cellulose-polyvinyl alcohol sponge for parabens analysis in food samples

An eco-friendly, simple, and reusable deep eutectic solvents (DESs)–microcrystal cellulose (MCC)–polyvinyl alcohol (PVA) sponge was synthesized using DESs adsorbed on MCC (DESs–MCC), which was subsequently entrapped in a PVA sponge. Under optimal conditions, good linearities were achieved in the concentration range from 0.8 ng mL−1 to 1.6 µg mL−1 for methylparaben (MP) and from 1.6 ng mL−1 to 1.6 µg mL−1 for ethylparaben (EP), propylparaben (PP), and butylparaben (BP). The limits of detection (LODs) were 560.2 ± 2.1, 642.4 ± 4.2, 611.1 ± 3.7, and 746.8 ± 5.6 pg mL−1 for MP, EP, PP, and BP, respectively. Good sorbent-to-sorbent reproducibility (n = 6, %RSD ≤ 4.0) and precision (n = 6, %RSD < 6.0) were also obtained. Interestingly, the DESs–MCC/PVA sponge can be reused up to five times retaining > 80% of its extraction efficiency. The developed DESs–MCC/PVA sponge was able to determine four parabens in milk, beverages, and tea samples; MP and EP were detected in two beverages and tea samples in the range of 29.0 ± 1.1–38.4 ± 1.3 ng mL−1 and 8.01 ± 0.95–10.6 ± 1.2 ng mL−1, respectively. Good recoveries were obtained in the range of 87.6 ± 3.5%–100.8 ± 4.7% for all the tested parabens in the samples. In conclusion, the development of DESs–MCC entrapped in a PVA sponge is simple and environmentally friendly, affording a reusable DESs–MCC/PVA sponge. Additionally, the DESs–MCC/PVA sponge exhibited good efficiency and is promising for the extraction of various trace organic substances.

Isolation of Cellulase from Selected Fungal Strains and Its Use for Manufacture Microcrystal Cellulose from Kapuk Cortex (Ceiba Pentandra (L.) Gaertn)

This study aims to obtain cellulase enzymes from selected molds for microcrystalline cellulose preparation from ????-cellulose of kapok cortex. Alpha-cellulose was obtained by biodelignification, and the purified cellulase was obtained from the selected mold. The Microcrystalline cellulose obtained from enzymatic hydrolysis was then identified FTIR and DSC, followed by characterization of microcrystalline cellulose, Particle Size and Distribution Analysis (PSA), and Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX), Loss on drying, pH, bulk density, tapped density, and flow rate. Biodelignification produced 14.88% ????-cellulose, Penicillium sp. the selected mold had the highest cellulase activity, with a cellulolytic index of 4.83. FTIR identification was similar to Avicel PH 101 with a melting point of 244.580°C. Loss on drying was 3.74%, pH was 7.0, particle size ranged from 13.06 to 196.79 ????m, bulk density and tapped density were 0.11 g/cm3 and 0.23 g/cm3, respectively flow rate character is quite good. SEM-EDX was showed that the morphological shape of the microcrystalline cellulose of the kapok cortex is elongated. Microcrystalline cellulose has shown a quite similar in character and can be furthered.

Light scattering properties of cellulose microcrystals from multiple angles under a magnetic field

Cellulose is a promising sustainable material due to its flexibility and high strength. The light scattering characteristics of anisotropic cellulose crystals from various angles with magnetic orientation were experimentally clarified in this study. The intensity of the light scattered from cellulose crystals is reduced by the application of a magnetic field. Therefore, it was suggested that switching the magnetic field would allow the light intensity to be controlled similarly to an attenuator.

Bio-Catalysis for the Functionalization of Cellulose Nanocrystals.

In this work, the chemical modification of cellulose nanocrystals (NCs) using an enzyme as a catalyst has been performed by a "grafting from" reaction, in order to covalently functionalize the external surface of NCs with both poly(L-lactic acid) (PLLA) and poly(ε-caprolactone) (PCL) by ring-opening polymerization. Firstly, cellulose nanocrystals were prepared from commercial cellulose microcrystals by acid hydrolysis and then functionalized by using Yarrowia lipolytica&amp;nbsp;lipase immobilized on Lewatit resin as a catalyst. To confirm the success of the grafting reactions, 1H-NMR has been performed as well as FT-IR and Raman spectroscopy. Moreover, thermogravimetric analysis has been used to determine the amount of polymeric chains grafted onto the surface of cellulose nanocrystals. Furthermore, the crystalline nature of the polymeric chains grafted onto the cellulose surface has been studied by DSC, X-ray scattering, as well as SAXS analysis. To our knowledge, it is the first time that a biocatalyst approach has been used to obtain biopolymeric functionalized cellulose nanocrystals.

Iridium-Functionalized Cellulose Microcrystals as a Novel Luminescent Biomaterial for Biocomposites

Microcrystalline cellulose (MCC) is an emerging material with outstanding properties in many scientific and industrial fields, in particular as an additive in composite materials. Its surface modification allows for the fine-tuning of its properties and the exploitation of these materials in a plethora of applications. In this paper, we present the covalent linkage of a luminescent Ir-complex onto the surface of MCC, representing the first incorporation of an organometallic luminescent probe in this biomaterial. This goal has been achieved with an easy and sustainable procedure, which employs a Bronsted-acid ionic liquid as a catalyst for the esterification reaction of -OH cellulose surface groups. The obtained luminescent cellulose microcrystals display high and stable emissions with the incorporation of only a small amount of iridium (III). Incorporation of MCC-Ir in dry and wet matrices, such as films and gels, has been also demonstrated, showing the maintenance of the luminescent properties even in possible final manufacturers.

Correlation between physicochemical characteristics of lignin deposited on autohydrolyzed wood chips and their cellulase enzymatic hydrolysis

Enzymatic hydrolysis is a method to generate biofuel from biomass, and autohydrolysis is a popular method to pretreat biomass prior to enzymatic hydrolysis. The primary aim of the present study was to determine the role of lignin produced in the autohydrolysis process on the enzymatic hydrolysis of biomass. The HSQC and 31P NMR analyses confirmed that β-O-4 of lignin was reduced, while β-5, β-β, and S/G-ratio of lignin were increased with intensifying the hydrolysis intensity.The increase in the hydrolysis intensity significantly enhanced the condensed and non-condensed phenolic OH group of lignin. Interestingly, the cellulase enzyme adsorbed more on lignin that had more phenolic content, and its association with lignin reduced its activity for hydrolyzing cellulose microcrystals. Strong negative correlations were observed between the enzymatic hydrolysis yield and the condensed S-OH (r2 = 0.978) and G-OH (r2 = 0.961) of lignin generated in the autohydrolysis process.

Formulation of Orally Disintegrating Tablets of Captopril as Superdisintegrant using Corncob (Zea mays L.)

AIM: This study aimed to make corncobs the basic material for the manufacture of microcrystalline cellulose. METHODS: Manufacture of corncob cellulose microcrystals (CCMs) by isolating alpha-cellulose from corncobs, then hydrolyzed with HCl 2.5 N. The yield of CCMs of 14.51% can be used as orally disintegrating tablet (ODT) and has similarities with Avicel as standard comparison. RESULTS: Both organoleptic results were pH 5.6 and 6.54; drying shrinkage 3.33% and 4.39%; total ash content 0.17% and 0.02%; and water solubility 0.9% and 0.12%. Furthermore, the real specific gravity is 0.317 and 0.306 g/cm3, incompressible density is 0.379 and 0.375 g/cm3, the true density is 1.291 and 1.206 g/cm3, Hausner index is 1.195 and 1.225, compressibility index is 19.55 and 22.55%, and porosity is 75.5 and 74.6%. CONCLUSION: Captopril ODT tablet preparations with CCM as filler have almost the exact tablet evaluation results compared to Avicel and to meet the requirements.

Characterization of high amylose starch-microcrystalline cellulose based floatable gel for enhanced gastrointestinal retention and drug delivery

Floatable high amylose rice starch and microcrystalline cellulose hybrid gels were developed for gastric drug delivery purposes. The concentration of microcrystal cellulose was varied from 1 to 4% to provide the porous rigid surface with high floatability and thermal stability. The hybrid gels showed high water holding capacity (419.11–459.54%), peak force (140.39–255.32 N), and floatability (8–27 h). The high peak temperature (114.1–122.5 °C) and residual mass 17.59–33.33% confirmed the thermal stability of the hybrid gel. The in-vitro drug release and gastrointestinal digestion behavior of the gel was studied with glycyrrhizic acid as a model drug. For the increase in the microcrystalline cellulose concentration in the gel, the loading efficiency and release of glycyrrhizic acid was decreased. Moreover, the release of glycyrrhizic acid in different digestion stages varied significantly with microcrystalline cellulose concentration in the hybrid gels. A Fickian diffusion mode for the release of loaded drug was also observed. The present study manifests improved gastro-retentive drug delivery systems with rice starch and cellulose hybrid gels.

Morphological and Physicochemical Properties of Nanostructured Cellulose Obtained through Chemical and Biological Methods

The authors obtained samples of chemically pure, crystalline, microand nanostructured cellulose of various modifications using two approaches – biological and chemical. They studied these cellulose samples via scanning electron microscopy (SEM), thermogravimetric analysis, and infrared (IR) spectroscopy. To prepare cellulose microcrystals, they used the mild acid treatment method based on glycerolacid mixtures for treating cotton fibers. They showed that the chemical processing of cotton fiber ensured its dispersion with generation of microcrystals surrounded by a partially preserved amorphous shell. The authors produced bacterial cellulose (BC) films using the Komagataeibacter xylinus C3 strain in surface cultivation conditions. With a view of obtaining higher-quality SEM images, they applied chemical fixation of lipids and proteins with critical drying to fix the process of nanofiber synthesis by bacterial cells. The two-step fixation method helped find the fibrillar structure of a cellulose film, while the morphology of bacterial cells was not deformed. The authors made a comparative analysis of the IR spectroscopy results between chemically synthesized cellulose microcrystals and BC. The obtained cellulose samples do not contain lignin and hemicellulose, both samples are highly crystalline. The BC has an ordered structure, higher crystallinity and gets carbonized when exposed to air pyrolysis. A thermogravimetric analysis of the samples shows the absence of thermally stable impurities. Both cellulose samples of biological and chemical origin are thermally stable, and the initial decomposition temperature is high enough for cellulose materials. These results show that the authors have managed to create nanocellulose materials that might be potentially applied in various industries, such as pharmaceuticals, functional composites, engineering, etc.