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#10 Científicos desarrollan "madera transparente"

--450164-- — Thu, 31 Mar 2016 17:17:27 +0000

[Usuario deshabilitado]

» autor: --450164--

#9 Científicos desarrollan "madera transparente"

Pezzonovante — Thu, 31 Mar 2016 16:20:34 +0000

#7 No sólo eso. "Transparent wood with a cellulosic wood template volume fraction of 19% showed twice as high strength and modulus as for neat PMMA."

Puedes verlo en el gráfico de la derecha en #4

» autor: Pezzonovante

#8 Científicos desarrollan "madera transparente"

--432809-- — Thu, 31 Mar 2016 16:16:29 +0000

#4 85% no está nada mal

» autor: --432809--

#7 Científicos desarrollan "madera transparente"

--432809-- — Thu, 31 Mar 2016 16:15:55 +0000

#3 la madera es la base del producto, el PMMA se añade sólo para alterar su transparencia

» autor: --432809--

#6 Científicos desarrollan "madera transparente"

Pezzonovante — Thu, 31 Mar 2016 16:14:26 +0000

#3 Resumen: extren la lignina y la substituyen por acrilico.

Delignification
Balsa wood (Ochroma pyramidale, purchased from Wentzels Co. Ltd., Sweden) with a density of 160 kg/m3 was dried at 105 ± 3 °C for 24 h before chemical extraction. The dried samples were extracted using 1 wt % of sodium chlorite (NaClO2, Sigma-Aldrich) with acetate buffer solution (pH 4.6) at 80 °C.(19) The sample dimension is 20 mm × 20 mm, with a thickness of 0.6 ± 0.1, 1.0, 2.5 ± 0.1, 5.0, and 8.0 mm. The reaction time for samples with thicknesses below 3 mm was 6 h and 12 h for samples with larger thicknesses of 5 and 8 mm. More reactions were done on samples with dimension of 100 mm × 100 mm × 1 mm to show the feasibility to work on larger samples. The extracted samples were carefully washed with deionized water followed by dehydration using first pure ethanol, then a 1:1 (volume ratio) mixture of ethanol and acetone, and finally, pure acetone (step by step). Each step was repeated three times.

Fabrication of Transparent Wood
Transparent wood was made by infiltrating the delignified wood template by a prepolymerized methyl methacrylate (MMA) solution and heated in an oven at 70 °C for 4 h. Pure MMA monomer was prepolymerized at 75 °C for 15 min in two-necked round-bottom flask with 0.3 wt % 2,2′-Azobis (2- methylpropionitrile) (AIBN, Sigma-Aldrich) as initiator. The prepolymerized MMA was cooled down to room temperature in ice–water bath to terminate the reaction. After that, the delignified wood template was infiltrated in prepolymerized MMA solution under vacuum for 30 min. Vacuum infiltration was repeated three times to ensure the full infiltration. Finally, the infiltrated wood was sandwiched between two glass slides and packaged in aluminum foil before further polymerization. The polymerization process was completed by heating the infiltrated wood sample in an oven at 70 °C for 4 h.

pubs.acs.org/doi/full/10.1021/acs.biomac.6b00145

» autor: Pezzonovante

#5 Científicos desarrollan "madera transparente"

pepel — Thu, 31 Mar 2016 16:13:32 +0000

A vueltas otra vez con la co..-..la light; será el nombre que quieran, pero madera no.

» autor: pepel

#4 Científicos desarrollan "madera transparente"

Pezzonovante — Thu, 31 Mar 2016 16:11:19 +0000

Parece bastante transparente.
pubs.acs.org/doi/abs/10.1021/acs.biomac.6b00145

» autor: Pezzonovante

#3 Científicos desarrollan "madera transparente"

--454746-- — Thu, 31 Mar 2016 16:11:16 +0000

En realidad han desarrollado un material entre cuyos ingredientes está la madera, pero de ahí a madera transparente...

» autor: --454746--

#2 Científicos desarrollan "madera transparente"

--82927-- — Thu, 31 Mar 2016 16:03:16 +0000

[Usuario deshabilitado]

» autor: --82927--

#1 Científicos desarrollan "madera transparente"

--432809-- — Thu, 31 Mar 2016 15:59:26 +0000

"Es atractivo que el material provenga de fuentes renovables", dice Berglund. "También ofrece excelentes propiedades mecánicas, incluyendo resistencia, tenacidad, baja densidad y baja conductividad térmica," añadió.

muy prometedor...

» autor: --432809--