5 research outputs found
Luminescent and Transparent Wood Composites Fabricated by Poly(methyl methacrylate) and γ‑Fe<sub>2</sub>O<sub>3</sub>@YVO<sub>4</sub>:Eu<sup>3+</sup> Nanoparticle Impregnation
Natural wood is functionalized
using the index matching polyÂ(methyl
methacrylate) (PMMA) and luminescent γ-Fe<sub>2</sub>O<sub>3</sub>@YVO<sub>4</sub>:Eu<sup>3+</sup> nanoparticles to form a novel type
of luminescent and transparent wood composite. First, the delignified
wood template was obtained from natural wood through a lignin removal
process, which can be used as a support for transparent polymer and
phosphor nanoparticles. Then, the functionalization occurs in the
lumen of wood, which benefits from PMMA that fills the cell lumen
and enhances cellulose nanofiber interaction, leading to wood composites
with excellent thermal properties, dimensional stability, and mechanical
properties. More importantly, this wood composite displays a high
optical transmittance in a broad wavelength range between 350 and
800 nm, magnetic responsiveness, and brightly colored photoluminescence
under UV excitation at 254 nm. The unique properties and green nature
of the luminescent wood composite have great potential in applications
including green LED lighting equipment, luminescent magnetic switches,
and anti-counterfeiting facilities
Legislative Documents
Also, variously referred to as: House bills; House documents; House legislative documents; legislative documents; General Court documents
Coherent-Interface-Assembled Ag<sub>2</sub>O‑Anchored Nanofibrillated Cellulose Porous Aerogels for Radioactive Iodine Capture
Nanofibrillated
cellulose (NFC) has received increasing attention in science and technology
because of not only the availability of large amounts of cellulose
in nature but also its unique structural and physical features. These
high-aspect-ratio nanofibers have potential applications in water
remediation and as a reinforcing scaffold in composites, coatings,
and porous materials because of their fascinating properties. In this
work, highly porous NFC aerogels were prepared based on <i>tert</i>-butanol freeze-drying of ultrasonically isolated bamboo NFC with
20–80 nm diameters. Then nonagglomerated 2–20-nm-diameter
silver oxide (Ag<sub>2</sub>O) nanoparticles (NPs) were grown firmly
onto the NFC scaffold with a high loading content of ∼500 wt
% to fabricate Ag<sub>2</sub>O@NFC organic–inorganic composite
aerogels (Ag<sub>2</sub>O@NFC). For the first time, the coherent interface
and interaction mechanism between the cellulose I<sub>β</sub> nanofiber and Ag<sub>2</sub>O NPs are explored by high-resolution
transmission electron microscopy and 3D electron tomography. Specifically,
a strong hydrogen between Ag<sub>2</sub>O and NFC makes them grow
together firmly along a coherent interface, where good lattice matching
between specific crystal planes of Ag<sub>2</sub>O and NFC results
in very small interfacial straining. The resulting Ag<sub>2</sub>O@NFC
aerogels take full advantage of the properties of the 3D organic aerogel
framework and inorganic NPs, such as large surface area, interconnected
porous structures, and supreme mechanical properties. They open up
a wide horizon for functional practical usage, for example, as a flexible
superefficient adsorbent to capture I<sup>–</sup> ions from
contaminated water and trap I<sub>2</sub> vapor for safe disposal,
as presented in this work. The viable binding mode between many types
of inorganic NPs and organic NFC established here highlights new ways
to investigate cellulose-based functional nanocomposites
Coherent-Interface-Assembled Ag<sub>2</sub>O‑Anchored Nanofibrillated Cellulose Porous Aerogels for Radioactive Iodine Capture
Nanofibrillated
cellulose (NFC) has received increasing attention in science and technology
because of not only the availability of large amounts of cellulose
in nature but also its unique structural and physical features. These
high-aspect-ratio nanofibers have potential applications in water
remediation and as a reinforcing scaffold in composites, coatings,
and porous materials because of their fascinating properties. In this
work, highly porous NFC aerogels were prepared based on <i>tert</i>-butanol freeze-drying of ultrasonically isolated bamboo NFC with
20–80 nm diameters. Then nonagglomerated 2–20-nm-diameter
silver oxide (Ag<sub>2</sub>O) nanoparticles (NPs) were grown firmly
onto the NFC scaffold with a high loading content of ∼500 wt
% to fabricate Ag<sub>2</sub>O@NFC organic–inorganic composite
aerogels (Ag<sub>2</sub>O@NFC). For the first time, the coherent interface
and interaction mechanism between the cellulose I<sub>β</sub> nanofiber and Ag<sub>2</sub>O NPs are explored by high-resolution
transmission electron microscopy and 3D electron tomography. Specifically,
a strong hydrogen between Ag<sub>2</sub>O and NFC makes them grow
together firmly along a coherent interface, where good lattice matching
between specific crystal planes of Ag<sub>2</sub>O and NFC results
in very small interfacial straining. The resulting Ag<sub>2</sub>O@NFC
aerogels take full advantage of the properties of the 3D organic aerogel
framework and inorganic NPs, such as large surface area, interconnected
porous structures, and supreme mechanical properties. They open up
a wide horizon for functional practical usage, for example, as a flexible
superefficient adsorbent to capture I<sup>–</sup> ions from
contaminated water and trap I<sub>2</sub> vapor for safe disposal,
as presented in this work. The viable binding mode between many types
of inorganic NPs and organic NFC established here highlights new ways
to investigate cellulose-based functional nanocomposites
High-Performance Wet Adhesion of Wood with Chitosan
Strong adhesion is desirable when using wood with a wide
range
of moisture contents, but most of the existing adhesives face challenges
in bonding wood under high-humidity conditions. Here, we report a
simple strategy that involves the one-step dissolution of chitosan
powder in acetic acid at room temperature, followed by direct use
of the resulting chitosan slurry as an adhesive on dry/wet wood veneers.
Mechanical interlocks and hydrogen bonds at cell wall interfaces provided
strong adhesion. Moreover, heat treatment induced recrystallization
and cross-linking of chitosan chains, resulting in a high cohesion.
Meanwhile, heat treatment caused the acetylation reaction between
the protonated amino groups (NH3+) of chitosan
and acetate groups (CH3COO–) to produce
hydrophobic acetyl groups. In addition, we prepared wooden products
such as plywood (dry veneers) and wooden straws (wet veneers) using
wood veneers with different moisture contents. The tensile shear strengths
under 63 °C water and under boiling water of plywood were 1.12
and 0.81 MPa, respectively. The compressive strength of wooden straws
is up to 35.32 MPa, which was higher than that of existing commercial
straws (such as paper straws, polypropylene straws, and plastic straws).
The chitosan wet adhesive showed good water resistance, high bonding
strength, environmental degradability, and nontoxicity, thus providing
a highly promising alternative to traditional wood composite adhesives