The use of halloysite functionalized with isothiouronium salts as an organic/inorganic hybrid adsorbent for uranium(VI) ions removal.

As part of a series of investigations into the relationship between chemical structure and biological activity1 , a number of 3-phenyl-4-hydroxycoumarins with alkylsubstituents in the 3-phenyl group were synthesized.

Synthesis of alkyl-substituted 3-phenyl-4-hydroxycoumarins

A gas adsorption rigid spheres model (RSM) was incorporated into the CPSM model (corrugated pore structure model) to correlate the pore surface areas obtained from the BET and CPSM methods. The latter is a method simulating the gas sorption hysteresis loop and enables the evaluation of surface areas S(CPSM) through the integration of the pertinent pore size distributions. Thus, S(CPSM) values are inherently influenced by pore curvature. The new CPSM-RSM version estimates surface areas S(CPSMfs) that are independent of pore curvature and can be compared with the pertinent S(BET) values. The RSM exploits the fact that a curved pore surface accommodates fewer molecules, assumed to behave as rigid spheres, than an equal flat one. Thus, the RSM accounts for a higher molecular surface coverage Ac (nm2/molec.) in pores with marked curvature than that (i.e., Af) on a flat surface. The ratio Ac/Af for nitrogen adsorbed on single pore sizes varies in the range Ac/Af = 1.44-1.03 for pore sizes D = 1.5-15 nm, respectively. Also for D = 1.5-5.0 nm the S(CPSMfs) and S(BET) values are lower by approximately 10-45% than the S(CPSM) estimates. From the application of the CPSM-RSM model on several porous materials exhibiting all known types of sorption hysteresis loops, it was confirmed that S(BET) approximately S(CPSMfs) (+/-5%) and (S(CPSM) - S(BET))/S(BET) = 3-68% for the materials examined. In conclusion, the BET method may produce quite conservative surface area estimates for materials exhibiting pore structures with appreciable pore curvature, whereas the CPSM-RSM model can reliably predict both S(CPSM) and S(CPSMfs) = S(BET) values.

Rigid Sphere Molecular Model Enables an Assessment of the Pore Curvature Effect upon Realistic Evaluations of Surface Areas of Mesoporous and Microporous Materials

Bioalkylation of dibenz[a,b]anthracene in rat liver cytosol.

Synthesis of polyazohydrazides

The Synthesis of 1,4-Dimethyl-6,7-methylenedioxyphenanthrene and of Certain Substituted 9,10-Dimethyl-1,2,5,6-dibenzanthracenes

The Synthesis of 1,4-Dimethylphenanthrene by the Pschorr Reaction, and the Non-identity of the Product with the 1,4-Dimethylphenanthrene of Bardhan and Sengupta1

Russell Bliss Akin

Papers

The Synthesis of 1,4-Dimethyl-6,7-methylenedioxyphenanthrene and of Certain Substituted 9,10-Dimethyl-1,2,5,6-dibenzanthracenes

The Synthesis of 1,4-Dimethylphenanthrene by the Pschorr Reaction, and the Non-identity of the Product with the 1,4-Dimethylphenanthrene of Bardhan and Sengupta1