Abstract: Liquid crystal monomers and polymers containing fluorinated alkyl chain have been prepared. The polymerization initiated by [Rh(nbd)Cl]2 has afforded the products in moderate to high yields. The molecular weight of polymers has been measured with gel permeation chromatography (GPC), the results show that the transition metal catalyst in THF/Et3N solvent system gives the best results for the polymerization. Monomers and polymers are characterized by IR and 1HNMR, and the liquid crystalline properties are evaluated by using POM, DSC and TGA. The results show that the monomers with fluorinated chain and polymers show SmA phase. The fluorinated polymers possess higher clearing points and broader mesophases than the alkyl chain polymers.

Abstract: The binding constants, standard molar enthalpy, Gibbs free energy, and entropy changes were determined for the formation of complexes between adamantyl derivatives and a β-cyclodextrin dimer. It is concluded that, within experimental error, the two cyclodextrin residues in the dimer behave independent to each other when complexing the adamantyl derivatives.

Abstract: An AM1 semiempirical method (Gaussian 03) was used to perform molecular structure optimizations in gas phase of two tail-to-tail bile acid-based dimers by an isophthalic acid bridge. The method was also used to study the interactions with the potential guest ibuprofen with the idea of applicative results.

Abstract: New dimeric steroid-based surfactants derived from 3α,7α,12α-trihydroxy-5β- cholan-24-amine (steroid residue) and isophthalic acid, 5,5'-biisobenzofuran-1,1',3,3'- carboxylic acid and succinic acid (spacers) were synthesized and structurally characterized by NMR techniques. The first spacer was also employed to synthesize the dimer corresponding to the 3α,12α-dihydroxy-5β-cholan-24-amine residue. In all cases the steroid residues are tail-to-tail linked through amide bonds with the spacers.

Abstract: Cyclodextrins (CDs) are natural‐occurring oligomers with a hydrophobic cavity which allow them to form inclusion complexes in water with a variety of organic molecules. These complexes are generally stabilized by van der Waals and hydrophobic interactions, although specific host‐guest interactions can also play an important role.[1] In addition, geometrical and orientational requirements of both the guest and the host may control the association process, whereas the dissociation rate is determined by the strength of the interactions.[2] Therefore, a change of the cavity size or the rigidity of the host has dramatic effects on both the association and the dissociation rate constants and in consequence on the stability of the complexes.[3] Moreover, for a certain guest, stoichiometry and geometry of the inclusion complexes may also be much dependent on the host cavity size.[4] In this work we study the effects of CD cavity size on the stoichiometry, stability and structure of the complexes formed between the synthetic organic probe Dapoxyl and three natural cyclodextrins (α‐CD, β‐CD and γ‐CD) differing in the size of their inner cavity, using steady‐state and time‐resolved fluorescence techniques. The ditopic structure of this fluorophore together with its high sensitivity to the surroundings make it a useful model molecule to study the geometrical effects on the complexation. Complexation provokes strong changes in the fluorescent properties of Dapoxyl with a large blue shift of its emission spectrum and a great increase of the fluorescence quantum yield. The differences observed for the three CDs regarding stoichiometry, stability and fluorescence properties of the complexes are discussed on the basis of a size‐selective complexation of the Dapoxyl.

Abstract: In this paper we wish to report our results on investigation of the kind and the concentration of the hydroperoxides initiators on the polymerization rate. Four kinds of peroxides with different concentration have been examined such as), tert-butyl hydroperoxide (TBHP), cumene hydroperoxide (CHP), methyl ethyl ketone hydroperoxide (MEKP) and benzoyl peroxide (BP). Results show that the rate of the reaction depends on the type and percentage of initiators.

Abstract: Cellulose was modified by reaction with (N‐butyl‐N‐chloropropyl‐N,N‐dimethyl) ammonium bromide (BCDMAB). The optimum reaction conditions were as follows: temperature 55°C, reaction time 3.2 h and mass ratio of cellulose:BCDMAB=1:2.5. Equilibrium adsorption capacity of modified cellulose for arsenate ion has been estimated. It's shown that this capacity increased with concentrations of arsenate ion. Structure of modified cellulose was confirmed by IR and SEM images.

Abstract: Cellulose was modified with citric acid in high temperature. Investigations of its absorption of heavy metal ions (such as Pb2+ and Cd2+) showed that modified cellulose in conditions 120°C and 12 h and in mass ratio of cellulose :citric acid=1:3 had highest absorption capacity. Absorption capacity of modified cellulose increased in accordance with increase of concentrations of ions. Structure of modified cellulose was confirmed by IR spectra and SEM pictures.

Abstract: Cellulose from cotton was modified through reaction of sodium carboxymethyl cellulose (NaCMC) with diethanolamine and an epichlorohydrinethylendiamine system in molar ratios of 1:1.5:1.5; 1:2:2; 1:3:3 and 1:4:4, respectively. The modification with epichlorohydrin-ethylendiamine was carried out in two steps: in the first step, NaCMC was reacted with epichlorohydrin, and in the second step, oxiran-2-ylmethyl carboxy-methylcellulose reacted with ethylendiamine gave cellulose-g-epichlorohydrin/ ethylendiamine. The surfaces of the obtained products have been investigated by SEM images. Their adsorption capability for Pb2+, Cd2+ and Mn2+ ions (at concentrations of 10,000, 2,000, 1,000, 600, 400 and 100 ppm) have been investigated.

Abstract: The binding constants, standard molar enthalpy, Gibbs free energy, and entropy changes were determined for the formation of inclusion complexes between 3α,7α,12α- trihydroxy-5β-cholan-24-amine, C₂₄NH2, and β-cyclodextrin and γ-cyclodextrin. The stoichiometry of both complexes is 1:1 in agreement with previously reported results for other trihydroxy bile salts. The equilibrium constant values for the formation of the inclusion complex are similar as well. The structure of the C₂₄NH2/γ-cyclodextrin complex was studied by ROESY experiments. These results suggest that B, C and Drings of the steroid skeleton, as well as the side chain, interact with the cyclodextrin cavity, while the A ring of the steroid nucleus remains outside the cavity.