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1.
Carbohydr Polym ; 241: 116423, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32507177

RESUMO

Olive fiber is a sustainable material as well as alternative biomass for extraction of nanocrystalline cellulose (NCC), which has been widely applied in various industries. In the present study, ONC-I, ONC-II, and ONC-III were extracted from olive stem fiber at different hydrolysis reaction times of 30 min, 45 min, and 60 min, respectively. The nanoparticle size was found gradually reducing from ONC-I (11.35 nm width, 168.28 nm length) to ONC-III (6.92 nm width, 124.16 nm length) due to the disintegration of cellulose fibrils. ONC-II and ONC-III possessed highly pure cellulose compartments and enhanced crystals structure. This study also showed that rigidity increased from ONC-I to ONC-II. ONC-III showed the highest crystallinity of 83.1 %, endowing it as a potentially reliable load-bearing agent. Moreover, ONC-III exhibited highest stable heat resistance among the chemically-isolated nanocellulose. We concluded that olive NCC could be promising materials for a variety of industrial applications in various fields.


Assuntos
Celulose , Fibras na Dieta/análise , Nanopartículas/química , Olea/química , Celulose/química , Celulose/isolamento & purificação
2.
Sci Rep ; 9(1): 14701, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31605015

RESUMO

Modulation of lithium-ion battery (LIB) anodes/cathodes with three-dimensional (3D) topographical hierarchy ridges, surface interfaces, and vortices promotes the power tendency of LIBs in terms of high-energy density and power density. Large-scale meso-geodesics offer a diverse range of spatial LIB models along the geodetically shaped downward/upward curvature, leading to open-ended movement gate options, and diffusible space orientations. Along with the primary 3D super-scalable hierarchy, the formation of structural features of building block egress/ingress, curvature cargo-like sphere vehicles, irregularly located serrated cuticles with abundant V-undulated rigidness, feathery tube pipe conifers, and a band of dagger-shaped needle sticks on anode/cathode electrode surfaces provides high performance LIB modules. The geodetically-shaped anode/cathode design enables the uniqueness of all LIB module configurations in terms of powerful lithium ion (Li+) movement revolving in out-/in- and up-/downward diffusion regimes and in hovering electron density for high-speed discharge rates. The stability of built-in anode//cathode full-scale LIB-model meso-geodesics affords an outstanding long-term cycling performance. The full-cell LIB meso-geodesics offered 91.5% retention of the first discharge capacity of 165.8 mAhg-1 after 2000 cycles, Coulombic efficiency of ~99.6% at the rate of 1 C and room temperature, and high specific energy density of ≈119 Wh kg-1. This LIB meso-geodesic module configuration may align perfectly with the requirements of the energy density limit mandatory for long-term EV driving range and the scale-up commercial manufactures.

3.
Int J Biol Macromol ; 102: 822-828, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28455253

RESUMO

The current study presents about the effect of cellulose nanofibers (CNFs) filler on the thermal and dynamic mechanical analysis (DMA) of epoxy composites as a function of temperature. In this study hand lay-up method was used to fabricate CNF reinforced Epoxy nanocomposites with CNF loading of 0.5%, 0.75%, and 1% into epoxy resin. The obtained thermal and DMA results illustrates that thermal stability, char content, storage modulus (E'), loss modulus (E") and glass transition temperature (Tg) increases for all CNF/epoxy nanocomposites compared to the pure epoxy. Thermal results revealed that 0.75% offers superior resistance or stability towards heat compared to its counterparts. In addition, 0.75% CNF/epoxy nanocomposites confers highest value of storage modulus as compared to 0.5% and 1% filler loading. Hence, it is concluded that 0.75% CNFs loading is the minimal to enhance both thermal and dynamic mechanical properties of the epoxy composites and can be utilized for advance material applications where thermal stability along with renewability are prime requirements.


Assuntos
Celulose/química , Compostos de Epóxi/química , Fenômenos Mecânicos , Nanofibras/química , Temperatura , Temperatura de Transição
4.
Int J Biol Macromol ; 97: 190-200, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28082223

RESUMO

Present study, deals about isolation and characterization of cellulose nanofibers (CNFs) from the Northern Bleached Softwood Kraft (NBSK) pulp, fabrication by hand lay-up technique and characterization of fabricated epoxy nanocomposites at different filler loadings (0.5%, 0.75%, 1% by wt.). The effect of CNFs loading on mechanical (tensile, impact and flexural), morphological (scanning electron microscope and transmission electron microscope) and structural (XRD and FTIR) properties of epoxy composites were investigated. FTIR analysis confirms the introduction of CNFs into the epoxy matrix while no considerable change in the crystallinity and diffraction peaks of epoxy composites were observed by the XRD patterns. Additions of CNFs considerably enhance the mechanical properties of epoxy composites but a remarkable improvement is observed for 0.75% CNFs as compared to the rest epoxy nanocomposites. In addition, the electron micrographs revealed the perfect distribution and dispersion of CNFs in the epoxy matrix for the 0.75% CNFs/epoxy nanocomposites, while the existence of voids and agglomerations were observed beyond 0.75% CNFs filler loadings. Overall results analysis clearly revealed that the 0.75% CNFs filler loading is best and effective with respect to rest to enhance the mechanical and structural properties of the epoxy composites.


Assuntos
Celulose/química , Resinas Epóxi/química , Fenômenos Mecânicos , Nanofibras/química , Teste de Materiais , Estresse Mecânico , Resistência à Tração
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