A Cellular Automata Approach for the Modeling of a Polyamide and Carbon Aerogel Structure and Its Properties.

In this work, a cellular automata (CA) approach was used to generate 3D structures of polyamide and carbon aerogels. Experimental results are used as initial data for materials' digital representations and to verify the developed CA models. Based on the generated digital structures, a computer study of aerogels' mechanical properties was conducted.

Large, Rapid Swelling of High- Polydicyclopentadiene Aerogels Suitable for Solvent-Responsive Actuators.

High- polydicyclopentadiene () aerogels were synthesized using ring opening metathesis polymerization (ROMP) of dicyclopentadiene () with a relatively air-stable ditungsten catalytic system, Na[W(-Cl)Cl(THF)]·(THF) (; (W W), ), and norbornadiene ()as a co-initiator. These aerogels are compared in terms of chemical structure and material properties with literature aerogels obtained using well-established Ru-based alkylidenes as catalysts. The use of as a co-initiator enhances the degree of crosslinking versus the more frequently used phenylacetylene (), yielding materials with a controlled molecular structure that would persist solvent swelling.

Synthetic Polymer Aerogels in Particulate Form.

Aerogels have been defined as solid colloidal or polymeric networks of nanoparticles that are expanded throughout their entire volume by a gas. They have high surface areas, low thermal conductivities, low dielectric constants, and high acoustic attenuation, all of which are very attractive properties for applications that range from thermal and acoustic insulation to dielectrics to drug delivery. However, one of the most important impediments to that potential has been that most efforts have been concentrated on monolithic aerogels, which are prone to defects and their production requires long and costly processing.

Millimeter-Size Spherical Polyurea Aerogel Beads with Narrow Size Distribution.

We report the room temperature synthesis of spherical millimeter-size polyurea (PUA) aerogel beads. Wet-gels of said beads were obtained by dripping a propylene carbonate solution of an aliphatic triisocyanate based on isocyanurate nodes into a mixture of ethylenediamine and heavy mineral oil. Drying the resulting wet spherical gels with supercritical fluid (SCF) CO₂ afforded spherical aerogel beads with a mean diameter of 2.

Poly(Urethane-Acrylate) Aerogels via Radical Polymerization of Dendritic Urethane-Acrylate Monomers.

The purpose of this work was to investigate the effect of multifunctionality on material properties of synthetic polymer aerogels. For this purpose, we present the synthesis and characterization of monolithic dendritic-type urethane-acrylate monomers based on an aliphatic/flexible (Desmodur N3300), or an aromatic/rigid (Desmodur RE) triisocyanate core. The terminal acrylate groups (three at the tip of each of the three branches, nine in total) were polymerized with 2,2'-azobis(isobutyronitrile) (AIBN) via free radical chemistry.

Poly(urethane-norbornene) Aerogels via Ring Opening Metathesis Polymerization of Dendritic Urethane-Norbornene Monomers: Structure-Property Relationships as a Function of an Aliphatic Versus an Aromatic Core and the Number of Peripheral Norbornene Moieties.

We report the synthesis and characterization of synthetic polymer aerogels based on dendritic-type urethane-norbornene monomers. The core of those monomers is based either on an aromatic/rigid (TIPM/Desmodur RE), or an aliphatic/flexible (Desmodur N3300) triisocyanate. The terminal norbornene groups (three at the tip of each of the three branches) were polymerized via ROMP using the inexpensive 1st generation Grubbs catalyst.