Efficient CO2 Sorbents Based on Silica Foam with Ultra-large Mesopores

A series of high-capacity, amine impregnated sorbents based on a cost-effective silica foam with ultra-large mesopores is reported. The sorbents exhibit fast CO2 capture kinetics, high adsorption capacity (of up to 5.8 mmol g−1 under 1 atm of dry CO2), as well as good stability over multiple adsorption–desorption cycles. A simple theoretical analysis is provided relating the support structure to sorbent performance.This publication was based on work supported by Award no. KUS-C1-018-02, made by King Abdullah University of Science and Technology (KAUST)

Fouling Release Nanostructured Coatings based on PDMS-polyurea Segmented Copolymers

http://www.elsevier.com/wps/find/journaldescription.cws_home/30466/description#descriptionThe bulk and surface characteristics of a series of coatings based on PDMS-polyurea segmented copolymers were correlated to their fouling release performance. Incorporation of polyurea segments to PDMS backbone gives rise to phase separation with the extensively hydrogen bonded hard domains creating an interconnected network that imparts mechanical rigidity. Increasing the compositional complexity of the system by including fluorinated or POSS-functionalized chain extenders or through nanoclay intercalation, confers further thermomechanical improvements. In analogy to the bulk morphology, the surface toporgraphy also reflects the compositional complexity of the materials, displaying a wide range of motifs. Investigations on settlement and subsequent removal of Ulva sporelings on those nanostructured surfaces indicate that the work required to remove the microorganisms is significantly lower compared to coatings based on standard PDMS homopolymer. All in all, the series of materials considered in this study demonstrate advanced fouling release properties, while exhibiting superior mechanical properties and thus, long term durability. (C) 2010 Elsevier Ltd. All rights reserved.This publication is based on work supported by the Office of Naval Research. This publication is also based on work supported in part by Award No. KUS-C1-018-02, made by King Abdullah University of Science and Technology (KAUST). We acknowledge facility support through the Cornell Center for Materials Research (CCMR) and the Nanobiotechnology Center (NBTC)

High efficiency nanocomposite sorbents for CO2 capture based on amine-functionalized mesoporous capsules

A novel high efficiency nanocomposite sorbent for CO2 capture has been developed based on oligomeric amine (polyethylenimine, PEI, and tetraethylenepentamine, TEPA) functionalized mesoporous silica capsules. The newly synthesized sorbents exhibit extraordinary capture capacity up to 7.9 mmol g-1 under simulated flue gas conditions (pre-humidified 10% CO2). The CO2 capture kinetics were found to be fast and reached 90% of the total capacities within the first few minutes. The effects of the mesoporous capsule features such as particle size and shell thickness on CO2 capture capacity were investigated. Larger particle size, higher interior void volume and thinner mesoporous shell thickness all improved the CO2 capacity of the sorbents. PEI impregnated sorbents showed good reversibility and stability during cyclic adsorption-regeneration tests (50 cycles)

Thermoreversible gelation in poly(ethylene oxide)/carbon black hybrid melts

The study focuses on the structure and viscoelasticity of poly(ethylene oxide)/carbon black fluids. The hybrids when subjected to extreme thermal annealing (at temperatures far above the melting point of the matrix) exhibit a 3-4 orders of magnitude increase in viscosity. Surprisingly, the effect is reversible and the viscosity reverts back to its initial value upon subsequent cooling. This rather unique sol-gel transition in terms of strength, steepness and thermal reversibility points to major structural rearrangements via extensive particle clustering, in agreement with microscopy observations. In related systems it was found that when matrix-particle electrostatic interactions are present the gelation is essentially diminished

Development of an operational high refractive index resist for 193nm immersion lithography

Generation-three (Gen-3) immersion lithography offers the promise of enabling the 32nm half-pitch node. For Gen-3 lithography to be successful, however, there must be major breakthroughs in materials development: The hope of obtaining numerical aperture imaging 1.70 is dependent on a high index lens, fluid, and resist. Assuming that a fluid and a lens will be identified, this paper focuses on a possible path to a high index resist. Simulations have shown that the index of the resist should be 1.9 with any index higher than 1.9 leading to an increased process latitude. Creation of a high index resist from conventional chemistry has been shown to be unrealistic. The answer may be to introduce a high index, polarizable material into a resist that is inert relative to the polymer behavior, but will this too degrade the performance of the overall system? The specific approach is to add very high index (~2.9) nanoparticles to an existing resist system. These nanoparticles have a low absorbance; consequently the imaging of conventional 193nm resists does not degrade. Further, the nanoparticles are on the order of 3nm in diameter, thus minimizing any impact on line edge roughness (LER)

Solution-Printed Organic Semiconductor Blends Exhibiting Transport Properties on Par with Single Crystals

Solution-printed organic semiconductors have emerged in recent years as promising contenders for roll-to-roll manufacturing of electronic and optoelectronic circuits. The stringent performance requirements for organic thin-film transistors (OTFTs) in terms of carrier mobility, switching speed, turn-on voltage and uniformity over large areas require performance currently achieved by organic single-crystal devices, but these suffer from scale-up challenges. Here we present a new method based on blade coating of a blend of conjugated small molecules and amorphous insulating polymers to produce OTFTs with consistently excellent performance characteristics (carrier mobility as high as 6.7 cm2V−1s−1, low threshold voltages of \u3c1V and low sub threshold swings \u3c0.5Vdec−1). Our findings demonstrate that careful control over phase separation and crystallization can yield solution-printed polycrystalline organic semiconductor films with transport properties and other figures of merit on par with their single-crystal counterparts

Development and Evaluation of a 193nm Immersion Generation-Three Fluid Candidates

The need to extend 193nm immersion lithography necessitates the development of a third generation (Gen-3) of high refractive index (RI) fluids that will enable approximately 1.7 numerical aperture (NA) imaging. A multi-pronged approach was taken to develop these materials. One approach investigated the highest-index organic thus far discovered. The second approach used a very high refractive index nanoparticle to make a nanocomposite fluid. This report will describe the chemistry of the best Gen-3 fluid candidates and the systematic approach to their identification and synthesis. Images obtained with the Gen-3 fluid candidates will also be presented for a NA ≥ 1.7

Characterization of Sulfur and Nanostructured Sulfur Battery Cathodes in Electron Microscopy Without Sublimation Artifacts

Lithium sulfur (Li-S) batteries have the potential to provide higher energy storage density at lower cost than conventional lithium ion batteries. A key challenge for Li-S batteries is the loss of sulfur to the electrolyte during cycling. This loss can be mitigated by sequestering the sulfur in nanostructured carbon-sulfur composites. The nanoscale characterization of the sulfur distribution within these complex nanostructured electrodes is normally performed by electron microscopy, but sulfur sublimates and redistributes in the high vacuum conditions of conventional electron microscopes. The resulting sublimation artifacts render characterization of sulfur in conventional electron microscopes problematic and unreliable. Here, we demonstrate two techniques, cryogenic transmission electron microscopy (cryo-TEM) and scanning electron microscopy in air (airSEM), that enable the reliable characterization of sulfur across multiple length scales by suppressing sulfur sublimation. We use cryo-TEM and airSEM to examine carbon-sulfur composites synthesized for use as Li-S battery cathodes, noting several cases where the commonly-employed sulfur melt infusion method is highly inefficient at infiltrating sulfur into porous carbon hosts

Development and Evaluation of a 193nm Immersion Generation-Three Fluid Candidates

The need to extend 193nm immersion lithography necessitates the development of a third generation (Gen-3) of high refractive index (RI) fluids that will enable approximately 1.7 numerical aperture (NA) imaging. A multi-pronged approach was taken to develop these materials. One approach investigated the highest-index organic thus far discovered. The second approach used a very high refractive index nanoparticle to make a nanocomposite fluid. This report will describe the chemistry of the best Gen-3 fluid candidates and the systematic approach to their identification and synthesis. Images obtained with the Gen-3 fluid candidates will also be presented for a NA ≥ 1.7

Fullerol ionic fluids

http://pubs.rsc.org/en/Content/ArticlePDF/2010/NR/C0NR00307G/2010-06-08?page=SearchWe report for the first time an ionic fluid based on hydroxylated fullerenes (fullerols). The ionic fluid was synthesized by neutralizing the fully protonated fullerol with an amine terminated polyethylene/polypropylene oxide oligomer (Jeffamine(R)). The ionic fluid was compared to a control synthesized by mixing the parially protonated from (sodium form) of hte fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding significantly perturbs the thermal transitions and melting/crystallization behavior of the amine. In contrast, both the normalized heat of fusion and crystallization of the amine in the control are similar to those of the neat amine consistent with a physical mixture of the fullerols/amine with minimal interactions. In addition to differences in thermal behavior, the fullerol ionic fluid exhibits a complex viscoelastic behavior intermediate between the neat Jeffamine (R) (liquid-like) and the control (solid-like).This publication is based on work supported in part by Award No. KUS-C1-018-02 made by King Abdullah University of Science and Technology (KAUST)