scholarly journals CHITOSAN-TEMPLATED LIGHTWEIGHT SPINEL CoAl2O4 NANOFIBRIL AEROGELS

2018 ◽  
Vol 56 (1A) ◽  
pp. 135
Author(s):  
Chau The Lieu Trang
Keyword(s):  
Aqueous Solution ◽  
Aluminum Hydroxide ◽  
Water Soluble ◽  
Metal Hydroxides ◽  
Cobalt Ions ◽  
Spider Web ◽  
Magnetic Ceramics ◽  
Aluminum Ions ◽  
Soluble Aluminum ◽  
Mixed Metal Hydroxides

We present lightweight macro-mesoporous spinel CoAl2O4 nanostructured aerogels derived from water-soluble aluminum-chitosan complexes. Chitosan nanofibrils interact with aluminum ions to swell into hydrogels. The aluminum-induced swelling is extended to dissolve the hydrogels in water to form a homogeneous aluminum-chitosan aqueous solution. The addition of cobalt ions in the aluminum-chitosan liquids which are solidified by lyophilization to generate cotton-like aerogel composites. Uniform incorporation of cobalt-aluminum hydroxide ions onto chitosan leads nanofibrils to serve as a hierarchical template to support mixed metal hydroxides in the aerogel composites. We investigated the thermal removal of chitosan template in the composites to obtain spinel CoAl2O4 aerogels that truly replicate spider web-like fibrillar networks of chitosan template. Enlarged porosity, high crystallinity, and lightweight make the CoAl2O4 aerogels useful as a colorful nano-pigment for magnetic ceramics.

Enantioselective Recognition of Chiral Guests by the Water-Soluble Chiral Keplerate {Mo132} Spherical Capsule with 30 Inner Lactate Ligands

2019 ◽  
Author(s):  
Nancy Watfa ◽  
Weimin Xuan ◽  
Zoe Sinclair ◽  
Robert Pow ◽  
Yousef Abul-Haija ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Chiral Recognition ◽  
Association Constants ◽  
Water Soluble ◽  
Enantioselective Recognition ◽  
H Nmr ◽  
Dosy Nmr ◽  
Spherical Capsule ◽  
Surface Pores ◽  
Guest Chemistry

Investigations of chiral host guest chemistry are important to explore recognition in confined environments. Here, by synthesizing water-soluble chiral porous nanocapsule based on the inorganic metal-oxo Keplerate-type cluster, {Mo<sub>132</sub>} with chiral lactate ligands with the composition [Mo<sub>132</sub>O<sub>372</sub>(H<sub>2</sub>O)<sub>72</sub>(<i>x-</i>Lactate)<sub>30</sub>]<sup>42-</sup> (<i>x</i> = D or L), it was possible to study the interaction with a chiral guest, L/D-carnitine and (<i>R</i>/<i>S</i>)-2-butanol in aqueous solution. The enantioselective recognition was studied by quantitative <sup>1</sup>H NMR and <sup>1</sup>H DOSY NMR which highlighted that the chiral recognition is regulated by two distinct sites. Differences in the association constants (K) of L- and D-carnitine, which, due to their charge, are generally restricted from entering the interior of the host, are observed, indicating that their recognition predominantly occurs at the surface pores of the structure. Conversely, a larger difference in association constants (K<i><sub>S</sub></i>/K<i><sub>R</sub></i> = 3) is observed for recognition within the capsule interior of (<i>R</i>)- and (<i>S</i>)-2-butanol.

scholarly journals Sulfobetaine Cryogels for Preferential Adsorption of Methyl Orange from Mixed Dye Solutions

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 208
Author(s):  
Ramona B. J. Ihlenburg ◽  
Anne-Catherine Lehnen ◽  
Joachim Koetz ◽  
Andreas Taubert
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Methyl Orange ◽  
Dye Removal ◽  
Selective Adsorption ◽  
Water Soluble ◽  
Organic Substances ◽  
Preferential Adsorption ◽  
Dimethyl Ammonium ◽  
Dye Solutions

New cryogels for selective dye removal from aqueous solution were prepared by free radical polymerization from the highly water-soluble crosslinker N,N,N’,N’-tetramethyl-N,N’-bis(2-ethylmethacrylate)-propyl-1,3-diammonium dibromide and the sulfobetaine monomer 2-(N-3-sulfopropyl-N,N-dimethyl ammonium)ethyl methacrylate. The resulting white and opaque cryogels have micrometer sized pores with a smaller substructure. They adsorb methyl orange (MO) but not methylene blue (MB) from aqueous solution. Mixtures of MO and MB can be separated through selective adsorption of the MO to the cryogels while the MB remains in solution. The resulting cryogels are thus candidates for the removal of hazardous organic substances, as exemplified by MO and MB, from water. Clearly, it is possible that the cryogels are also potentially interesting for removal of other compounds such as pharmaceuticals or pesticides, but this must be investigated further.

Electrochemical route for accessing amorphous mixed-metal hydroxide nanospheres and magnetism

RSC Advances ◽  
2015 ◽  
Vol 5 (56) ◽  
pp. 45359-45367 ◽  
Author(s):  
H. B. Li ◽  
Y. Q. Gao ◽  
G. W. Yang
Keyword(s):  
Metal Hydroxide ◽  
Electrochemical Technique ◽  
Homogeneous Distribution ◽  
Metal Hydroxides ◽  
Mixed Metal ◽  
Mixed Metal Hydroxides

Amorphous mixed-metal hydroxides nanospheres with a homogeneous distribution of metals in compositions including binary Fe–Co, Fe–Ni and Co–Ni and ternary Ni–Co–Fe hydroxides were prepared via a simple, facile and green electrochemical technique.

scholarly journals Blinking and nonradiant dark fraction of water-soluble quantum dots in aqueous solution

2005 ◽  
Vol 102 (40) ◽  
pp. 14284-14289 ◽  
Author(s):  
J. Yao ◽  
D. R. Larson ◽  
H. D. Vishwasrao ◽  
W. R. Zipfel ◽  
W. W. Webb
Keyword(s):  
Aqueous Solution ◽  
Quantum Dots ◽  
Water Soluble

Evidence of Variations in Atomic Distribution in Disordered Mixed Metal Hydroxides

MRS Advances ◽  
2019 ◽  
Vol 4 (33-34) ◽  
pp. 1843-1850
Author(s):  
Wen Rong ◽  
Sarah Stepan ◽  
Rodney D. L. Smith
Keyword(s):  
Transition Metal Oxides ◽  
Iron Ions ◽  
X Ray Diffraction ◽  
Metal Hydroxides ◽  
X Ray ◽  
Mixed Metal ◽  
Apparent Solubility ◽  
Fundamental Understanding ◽  
Double Hydroxides ◽  
Mixed Metal Hydroxides

ABSTRACTNumerous fabrication protocols are known to yield transition metal oxides with structures related to layered double hydroxides, but the effect of fabrication protocol on the uniformity of mixed-metal compositions remain largely unexplored. We have analysed the apparent solubility limits and the structural implications of iron ions in nickel hydroxide lattices for materials prepared by four different fabrication protocols. Opposing shifts in the (100) and (001) reflection in powder X-ray diffraction results revealed a contraction of the nickel lattice upon successful incorporation of iron, with Ni-M distances exhibiting an apparently linear decrease with respect to iron content. This feature revealed the amount of iron incorporated into nickel-based materials to be dependent on fabrication protocol, varying from apparently negligible concentrations to over fifty atomic percent. The dependency of structure on fabrication protocols provides a handle to improve fundamental understanding of catalytically relevant coordination environments.

A Novel Water Soluble Bipyrazolic Tripod Azoic Dye as Chemosensor for Copper (II) in Aqueous Solution

2018 ◽  
Vol 2 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Jalal Isaad ◽  
Tarik Harit ◽  
Haad Bessbousse ◽  
Ahmida El Achari ◽  
Fouad Malek
Keyword(s):  
Aqueous Solution ◽  
Water Soluble ◽  
Bipyrazolic Tripod
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