4,983 research outputs found
Controlling of green nanocellulose fiber properties produced by chemo-mechanical treatment process via SEM, TEM, AFM and image analyzer characterization
Nanocellulose fibers were extracted from Oil Palm Empty Fruit Bunch (OPEFB) fibers by a chemo-mechanical treatment process. The aim of this study is to observe and investigate the morphological structure and fiber dimension characteristic of each stage in the nanocellulose production. The fiber structure characterization of the raw, purified pulps, extracted cellulose and nanocellulose fibers were controlled by observation and investigation under Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM) and Image Analyzer. The morphological observation illustrated that the isolation of nanocellulose fibers had greatly decreased from micron to nanoscale, up to 5-10 nm in diameter, and therefore suitable to be used as quality nano-reinforcement in the polymer matrix for a potential environmental green nanobiocomposites development.Keywords: nanocellulose fibers; morphological observation; fiber dimension; SEM; TE
Utilization of Nanocellulose Fiber from Tapioca Industrial Solid Waste as a Bioplastic Filling Material
This study aims to examine the properties of nanocellulose fibers produced from cassava through the acid hydrolysis process, as well as their potential use as a filler for bioplastics based on cassava starch (tapioca). The treatment of this research was acid hydrolysis process time consisting of 15 and 30 minutes and the use of nanocellulose fiber as a filler for bioplastics as much as 0%, 1%, 2%, and 3% w/w starch. The results of this study indicate that the diameter of the nanocellulose fibers produced is about 18-40 nm, good dispersion stability, the crystallinity index of the nanocellulose fibers produced by acid hydrolysis for 15 and 30 minutes are 39.7% and 31.2%, respectively. The addition of nanocellulose fibers can increase the tensile strength, but decrease its elongation ability
Valorization of byproducts of hemp multipurpose crop: Short non-aligned bast fibers as a source of nanocellulose
Nanocellulose was extracted from short bast fibers, from hemp (Cannabis sativa L.) plants harvested at seed maturity, non-retted, and mechanically decorticated in a defibering apparatus, giving non-aligned fibers. A chemical pretreatment with NaOH and HCl allowed the removal of most of the non-cellulosic components of the fibers. No bleaching was performed. The chemically pretreated fibers were then refined in a beater and treated with a cellulase enzyme, followed by mechanical defibrillation in an ultrafine friction grinder. The fibers were characterized by microscopy, infrared spectroscopy, thermogravimetric analysis and X-ray diffraction after each step of the process to understand the evolution of their morphology and composition. The obtained nanocellulose suspension was composed of short nanofibrils with widths of 5–12 nm, stacks of nanofibrils with widths of 20–200 nm, and some larger fibers. The crystallinity index was found to increase from 74% for the raw fibers to 80% for the nanocellulose. The nanocellulose retained a yellowish color, indicating the presence of some residual lignin. The properties of the nanopaper prepared with the hemp nanocellulose were similar to those of nanopapers prepared with wood pulp-derived rod-like nanofibrils
Nanocellulose fibers: A Review of Preparation Methods, Characterization Techniques, and Reinforcement Applications
Cellulose, which occurs naturally in abundance, has the benefit of being the most widely used biomass material on a global scale. It is generated from natural fibers and can be processed to produce various types of nanocellulose fibers, each with its hierarchical configuration. This review summarizes current advances in the production of nanocellulose particles, focusing on the analytical techniques most widely used for their preparation, extraction, and characterization. These techniques include FT-IR, TGA, FESEM, and XRD. The review also demonstrates that research into nanocellulose fibers has progressed exponentially over the last decade (over 400 references). Many manufacturing techniques have been developed to use nanofibers in multiple applications as advanced sustainable materials. The presented data will reinforce the applications of nanocellulose fibers for various purposes
Cellulosic materials as natural fillers in starch-containing matrix-based films: a review
In this work, the different cellulosic materials, namely cellulose and lignin are analyzed. In addition, the starch-containing matrices (isolated starch and flour) reinforced with cellulosic materials to be used in packaging applications are described. Many efforts have been exerted to develop biopackaging based on renewable polymers, since these could reduce the environmental impact caused by petrochemical resources. Special attention has had the starch as macromolecule for forming biodegradable packaging. For these reasons, shall also be subject of this review the effect of each type of cellulosic material on the starch-containing matrix-based thermoplastic materials. In this manner, this review contains a description of films based on starch-containing matrices and biocomposites, and then has a review of cellulosic material-based fillers. In the same way, this review contains an analysis of the works carried out on starch-containing matrices reinforced with cellulose and lignin. Finally, the manufacturing processes of starch/cellulose composites are provided as well as the conclusions and the outlook for future works.Fil: Gutiérrez Carmona, Tomy José. Universidad Central de Venezuela; Venezuela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Alvarez, Vera Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin
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Nanocellulose aerogel-based porous coaxial fibers for thermal insulation
Strong, continuous, and highly porous coaxial fibers with cellulose nanofibril (CNF) aerogel core and cellulose-rich sheath were fabricated by wet-spinning hollow fibers and infusing them with aerogel precursor for high-performance thermal insulators. The sheath contained multiscale pores, including microvoids (14.5 μm) and sub-micron pores (133 nm) in bulk, as well as ca. 25–26 nm surface nanopores, to function as a template and protective sheath for the microporous CNF aerogel core. The porous coaxial fibers had many desirable qualities, including low density (0.2 g cm3), high porosity (85%), high specific tensile strength (23.5 ± 2.5 MPa g cm−3), wide working temperatures (−20 to 150 °C), continuous and large-scale producibility, as well as biodegradability. The unique combination of multiscale porous sheath and ultra-low density aerogel core synergistically minimizes heat conductivity by all three mechanisms, i.e., restrain air circulation to limit convective heat transfer, while the poor conducting cellulose permitting little conductive heat transfer and the highly crystalline aerogel cellular walls prohibit infrared radiation, effectively suppresses radiative heat transfer under extreme temperatures
Manufacturing Of Robust Natural Fiber Preforms Utilizing Bacterial Cellulose as Binder
We present a novel method of manufacturing rigid and robust short natural fiber preforms using a papermaking process. Bacterial cellulose acts simultaneously as the binder for the loose fibers and provides rigidity to the fiber preforms. These preforms can be infused with a resin to produce truly green hierarchical composites
Isolasi Nanoselulosa Terkarboksilasi dari Limbah Kulit Pisang Ambon Lumut dengan Metode Oksidasi
In this study, banana peel from ambon lumut (Musa acuminata) was used as source for nanocellulose fibers. Carboxylated nanocellulose was isolated with oxidation method using ammonium persulfate (APS). In order to investigate the effect of temperature towards the characteristics of nonocellulose, temperature for oxidation process was set at three different values: 60 °C, 70 °C, dan 80 °C. Nanostructure of cellulose was observed as a mix of fibers and whiskers from transmission electron microscopy (TEM) images. The diameter of nanocellulose is ranging from 12,1 to 25,1 nm. Data from spectrometry graphs (FTIR) confirms the existence of carboxyl functional groups in nanocellulose samples. X-ray diffraction pattern (XRD) shows that crystallinity index values increase as temperature of oxidation process increases. The highest crytallinity index value of 72,4% was obtained from nanocellulose treated with oxidation temperature of 80 °C. This analysis shows banana peel waste as a potential alternative source for carboxylated nanocellulose
Nanocellulose as building block for novel materials
This thesis describes the fabrication of novel green materials using nanocellulose as
the building block. Bacterial cellulose (BC) was used as the nanocellulose
predominantly in this work. BC is highly crystalline pure cellulose with an inherent
fibre diameter in the nano-scale. A single BC nanofibre was found to possess a
Young’s modulus of 114 GPa. All these properties are highly favourable for using
BC as a nanofiller/reinforcement in green nanocomposite materials.
In this work, the surface of BC was rendered hydrophobic by grafting organic acids
with various aliphatic chain lengths. These surface-modified BC was used as nanofiller
for poly(L-lactide) (PLLA). Direct wetting measurements showed that the BC
nanofibre-PLLA interface was improved due to the hydrophobisation of BC with
organic acids. This led to the production of BC reinforced PLLA nanocomposites
with improved tensile properties. Nanocellulose can also be obtained by grinding of
wood pulp, producing nanofibrillated cellulose (NFC). The surface and bulk
properties of one type of NFC and BC were compared in this work. Furthermore, the
reinforcing ability of NFC and BC was also studied and it was observed that there is
no significant difference in the mechanical performance of NFC or BC reinforced
nanocomposites.
A novel method based on slurry dipping to coat sisal fibres with BC was developed
to modify the surface of natural fibres. This method can produce either (i) a densely
BC coating layer or (ii) “hairy” BC coated sisal fibres. Randomly oriented short BC
coated sisal fibre reinforced hierarchical composites were manufactured. It was
found that hierarchical (nano)composites containing BC coated sisal fibres and BC
dispersed in the matrix were required to produce composites with improved
mechanical properties. This slurry dipping method was also extended to produce
robust short sisal fibre preforms. By infusing this preform with a bio-based
thermosetting resin followed by curing, green composites with significantly
improved mechanical properties were produced. BC was also used as stabiliser and
nano-filler for the production of macroporous polymers made by frothing of
acrylated epoxidised soybean oil followed by microwave curing
Textile Dyeing Using Nanocellulosic Fibers
Disclosed are various embodiments for dyeing a material using a dyed nanocellulose dispersion, thereby reducing or eliminating the need for water in dyeing materials, such as fabrics and textiles. A dyed nanocellulose dispersion or gel may be prepared from wood pulp fibers using a homogenizer and a dye, wherein the dyed nanocellulose dispersion comprises nanosized cellulose fibrils. The dyed nanocellulose gel may comprise an approximate concentration of 0.5% to 6%. The dyed nanocellulose dispersion may be applied to a material, such as a fabric or textile material. The fabric or textile material can be dried resulting in a dyed material
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