The conversion of the cellulose into 5-HMF would experience three steps, cellulose to glycose, glycose to fructose and fructose to 5-HMF. Chloride ion can break down the hydrogen bond in cellucose, chromium can catalyze the isomerization of glycose to fructose, and the high temperature is helpful to cyclohydration of fructose to 5-HMF. In this paper, the sawdust has been directly degraded i...

We describe a general multinuclear (1H, 23Na, 87Rb) NMR approach for direct detection of alkali metal ions bound to G-quadruplex DNA. This study is motivated by our recent discovery that alkali metal ions (Na+, K+, Rb+) tightly bound to G-quadruplex DNA are actually "NMR visible" in solution (Wong, A.; Ida, R.; Wu, G. Biochem. Biophys. Res. Commun. 2005, 337, 363). Here solution and solid-state...

The formation and stability of alkali metal complexes with crown ethers containing an anthraquinone unit has been investigated in methanol and acetonitrile solutions by potentiometric methods. Complexes of 1:1 stoichiometry were observed for all the studied systems; 2:1 complexes were only detected for the larger alkali cations (Rb and Cs) and with the ligand with the larger macrocyclic cavity ...

Recent studies by Berry et al. [1,2] of collisional dissociation of alkali halides by shockheated argon have shown that, in vibrationallyequilibrated gases, some alkali halides (all cesium, rubidium and potassium salts except RbI and KI) dissociate completely to ion pairs, although dissociation to neutral atoms requires less energy. An e_xpression for the branching ratio for the different disso...

We have observed depolarization effects when high intensity cold neutron beams are incident on alkali-metal spin-exchange-polarized 3He cells used as neutron spin filters. This was first observed as a reduction of the maximum attainable 3He polarization and was attributed to a decrease of alkali-metal polarization, which led us to directly measure alkali-metal polarization and spin relaxation o...

Porous membranes with ultrafast ion permeation and high ion selectivity are highly desirable for efficient mineral separation, water purification, and energy conversion, but it is still a huge challenge to efficiently separate monatomic ions of the same valence and similar sizes using synthetic membranes. We report metal organic framework (MOF) membranes, including ZIF-8 and UiO-66 membranes wi...

Thin films of iron(W) hexacyanoferrate(I1) (Prussian Blue) were electrochemically deposited on interdigitated array (IDA) electrodes, yielding systems which can be considered as chemiresistors in sensing alkali metal ion concentrations in an adjacent electrolyte. This is due to the fact that the conductivity of the film being measured by a steady-state current on application of a voltage to the...

Accurate calculations are made for the hydration energies of the alkali halides, using the most recent data. These results, and the average of theoretical calculations made by others for the individual ions, are used to determine the most probable hydration energy of the individual ions. These in turn are the basis for calculating the absolute enthalpy of formation of aqueous H: 98.6 kcal/g-equ...

The alkali-metal ion extraction ability of an inert material, polytetrafluoroethylene (PTFE; empirical formula CF2), was clarified by characterizing a partially alkali-metal ion-extracted layered compound, K0.8(Li0.27Ti1.73)O4. Washing K0.8(Li0.27Ti1.73)O4 in water extracts only 44% of the interlayer K(+) and no intralayer Li(+); on the other hand, 53% of the interlayer K(+) and approximately 1...

The single ion transport of transition metal ions like Cu(2+), Co(2+), Ni(2+) and Zn(2+) were carried out through the H(+) and alkali metal ion forms of Nafion membrane. These studies showed that the ion exchange selectivity coefficient of the permeating ion had an effect on its transport process. It was found that the diffusion coefficient values (D) were directly proportional to the selectivi...