Home » Posts filed under 2012
H. A. Patel,
C. T. Yavuz*
Chem. Comm., 48 (80), 9989 - 9991 (
2012). [
DOI] [
pdf]
Modifying sorbents for the purpose of improving carbon dioxide capture often results in the loss of surface area or accessible pores, or both. We report the first noninvasive functionalization of the polymers of intrinsic microporosity (PIMs) where inclusion of amidoxime functionality in PIM-1 increases carbon dioxide capacity up to 17 % and micropore surfaces at 20 % without losing its film forming ability.
H. A. Patel,
J. Byun,
C. T. Yavuz*
J. Nanopart. Res., 14 (7), 881 (
2012). [
DOI] [
pdf]
Nanoscale magnetite (Fe3O4) (15 nm) is known to remove arsenic efficiently but is very difficult to separate or require high magnetic fields to separate out from the waste water after treatment. Anisotropic hexagonal ferrite (BaFe12O19, BHF) is a well-known permanent magnet (i.e., fridge magnets) and attractive due to its low cost in making large quantities. BHF offers a viable alternative to magnetite nanocrystals for arsenic removal since it features surfaces similar to iron oxides but with much enhanced magnetism. Herein, we employ BHF nanocrystalline materials for the first time in arsenic removal from wastewater. Our results show better (75 %) arsenic removal than magnetite of the similar sizes. The BHF nanoparticles, 6.06 ± 0.52 nm synthesized by thermolysis method at 320 °C do not show hexagonal phase, however, subsequent annealing at 750 °C produced pure hexagonal BHF in 200 nm assemblies. By using BHF, we demonstrate that nanoparticle removal is more efficient and fixed bed type cartridge applications are more possible.
F. Karadas, H. El-Faki, E. Deniz, C.T. Yavuz*, S. Aparicio*, M. Atilhan*
Micropor. Mesopor. Mat., 162, 91-97, (2012). [DOI] [pdf] [WOS]
Carbon dioxide (CO2) adsorption capacities of several Prussian Blue (PB) analogues have been studied using the state-of-the-art Rubotherm® sorption apparatus to obtain adsorption and desorption isotherms of these compounds up to 50 bar. The analogues were prepared by simply reacting a [M(CN)6]3- (M= Co, Fe) solution with solutions of M2+ (M= Mn, Fe, Co, Ni, Cu) metal ions. Characterization of the studied samples has been performed by using a combination of powder XRD, TGA, FTIR, and CHN elemental analysis. Adsorption capacities of PB analogues calculated with theoretical calculations, using Monte Carlo approach, have also been compared with the experimental study, and used to discuss the molecular mechanism of adsorption.
S. T. Camli, F. Buyukserin,
C. T. Yavuz, M. S. Yavuz*
Mater. Chem. Phys., 134 (2–3), 1153–1159, (
2012). [
DOI] [
pdf]
We describe a facile protocol for the synthesis of PEGylated Au nanoparticles by simply mixing aqueous solutions of HAuCl
4 and oligo(ethylene glycol) ethyl ether methacrylate. This method was applied to generate uniform multiply-twinned Au nanostructures of ∼21 nm in diameter with high yields. Our proposed mechanism indicates that the generation of primary alcohol intermediates from the nucleophilic addition reaction of water (nucleophile) with AuIII–vinyl complex is responsible for the reduction of gold ions. This protocol was also used to synthesize Ag nanoparticles and small aggregates of Pd nanoparticles. Due to the exclusion of sophisticated synthesis of PEG containing stabilizers, additional surfactants, or reducing agents, this approach provides a remarkably simple, versatile, and environmentally benign protocol to prepare PEGylated noble-metal nanocrystals. A comparative BSA adsorption study proved the lack of non-specific binding, a common obstacle in designing biocompatible nanoparticles.
H. A. Patel, F. Karadas,
A. Canlier, J. Park, E. Deniz, Y. Jung, M. Atilhan*,
C. T. Yavuz*
J. Mater. Chem., 22, 8431-8437, (
2012). [
DOI] [
pdf]
With 5616 mg/g, COP-1 sets the new world record for the highest CO2 capture capacity
At infinite selectivity, COP-2 holds the world record in CO2/H2 separation
Efficient CO2 scrubbing without
a significant energy penalty remains an outstanding challenge for fossil fuel-burning
industry where aqueous amine solutions are still widely used. Porous materials
have long been evaluated for next generation CO2 adsorbents. Porous
polymers, robust and inexpensive, show promise as feasible materials for the
capture of CO2 from warm exhaust fumes. We report the syntheses of
porous covalent organic polymers (COPs) with CO2 adsorption
capacities of up to 5616 mg/g (measured at high pressures, i.e.200 bar) and
industrially relevant temperatures (as warm as 65 oC). COPs are stable
in boiling water for at least one week and near infinite CO2/H2
selectivity is observed.
Top five in CO2 capture capacity*:
1. COP-1: 5616 mg/g
2. MOF-210: 2870 mg/g
3. NU-100: 2315 mg/g
4. PPN-4: 2121 mg/g
5. COP-2: 2086 mg/g
*These capacities reflect the highest recorded values, regardless of the conditions. In addition, according to our recent high pressure data on common solids, we believe the rankings won't change much even if the pressures are raised.
+ This paper was published as is in 16 days after initial receipt
