Polyhedral Oligomeric Silsesquioxane-Reinforced Photopolymers Demonstrate High Sensitivity for Holographic Data Storage
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Polyhedral Oligomeric Silsesquioxane-Reinforced Photopolymers Demonstrate High Sensitivity for Holographic Data Storage Holographic data storage is a promising new method for recording digital information. This is because holography allows pages of data to be written at once, while storing multiple pages of data in a given volume. Photopolymers are attractive materials for use as holographic recording media due to their high sensitivity and low cost. However, a critical drawback of photopolymers is the volume shrinkage which occurs during polymerization. Now J.-K. Park and co-workers from Korea Advanced Institute of Science and Technology (KAIST) have shown that incorporating multifunctional molecular silicate “cages” into the polymer matrix of the holographic photopolymer reduces volume shrinkage while maintaining high photosensitivity.
Metal Organic Frameworks Achieve CO2-Specific Adsorption at Low Pressures Metal-organic frameworks (MOFs) have emerged as an important class of materials due to their porous nature and relative ease of design. Their low density (0.20–1.00 g/cm3) and high surface area (500–4500 m2/g) have brought MOFs into the forefront of gas storage and separation research. To date, a significant portion of relevant publications has focused on large-pore MOFs due to their ability to store higher volumes of gas. However, high pressures are usually needed in order for large-pore MOFs to adsorb extreme amounts of gases. Additionally, gas selectivity would be expected to decrease with increasing pore size. In general, gas sorption can be controlled by the MOF pore structures and the functionality
Sulfur- and Coking-Tolerant Material Could Expand Applications for SOFCs Solid-oxide fuel cells (SOFCs) use an electrochemical process to produce electricity by oxidizing a fuel. The ceramic electrolyte they use is yttria-stabilized zirconia (YSZ). The main drawbacks to SOFCs are their susceptibility to contamination from sulfur, deactivation from carbon build-up, and limited conductivity at low temperatures. Now M. Liu and colleagues at the Georgia Institute of Technology have developed a mixed ion conductor,
As reported recently in Optics Letters, to minimize volume shrinkage, the researchers created an organic–inorganic hybrid material using methacrylate-functionalized polyhedral oligomeric silses qui oxane (POSS) as a co-monomer. The polymer matrix consisted of PMMA with dibutylphthalate plasticizer, n-vinylcarbazole as a second co-monomer, and Irgacure 784 as the photoinitiator. Three compositions were tested with varying amounts of POSS: 0, 1, and 2 wt%. The researchers showed higher diffraction efficiency with systems that contained POSS. A maximum diffraction efficiency of 80% was achieved using 1 wt% POSS, compared to ~30% without POSS. Additionally, the diffraction efficiency increased more rapidly with higher concentrations of POSS. As a result, the photosensitivity more than doubled when 1 wt% POSS was added to the system. The researchers attribute the rapid growth in diffraction
efficiency to
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