National Laboratory of Nanotechnology

San José, Costa Rica

National Laboratory of Nanotechnology

San José, Costa Rica
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Camacho M.,National Laboratory of Nanotechnology | Urena Y.R.C.,National Laboratory of Nanotechnology | Lopretti M.,University of the Republic of Uruguay | Carballo L.B.,National Laboratory of Nanotechnology | And 4 more authors.
Journal of Renewable Materials | Year: 2017

Pineapple peel biomass was used as raw material for nanocellulose extraction. The raw material is a residue from the Costa Rican fruit industry. The nanocellulose was obtained by a two-step hydrolysis process. Firstly, the cellulose was hydrolyzed with HCl to obtain microcrystalline cellulose. In the second step, the hydrolysis was carried out using H2SO4 to obtain smaller fragments and decrease the lignin content. A time-dependent study was carried out to determine the particle size decrease depending on the contact time with the H2SO4. The chemical, thermal and morphological properties were analyzed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic light scattering (DLS), zeta potential, atomic force microscopy (AFM) and scanning electron microscopy (SEM). The nanofiber-like cellulose was obtained after 60 minutes of exposure to 65 wt% H2SO4.


Jimenez G.A.,National University of Costa Rica | Matamores X.,National University of Costa Rica | Sibaja M.,National University of Costa Rica | Jimenez L.,National University of Costa Rica | And 3 more authors.
Annual Technical Conference - ANTEC, Conference Proceedings | Year: 2011

High intensive mixing techniques and/or long ultrasonication periods of time are normally used to prepare epopy clay nanocomposites. However this approach is not practical. In this work epoxy clay nanocomposites were prepared using a combination of short times of ultrasonication and hand mixing, therefore making clay chemistry to govern over possible differences in the composite properties. Several types of nanoclay were used in order to investigate clay chemistry on thermal and mechanical properties of the nanocomposites. Flexural test proved to be more sensitive than tensile testing in determining the effect of type and clay content.

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