The kinetics of caffeine uptake into the interlayer nanospace of silicate nanosheets modified with benzylammonium (BA) was evaluated by in situ monitoring the basal spacing in aqueous media using transmission X-ray diffraction. An interlayer spacing of 0.58 nm in water before caffeine uptake indicates a monomolecular layer of BA and a few water layers in each interlayer. The interlayer space expanded by 0.10 nm upon caffeine uptake (intercalation) and saturated even in the presence of excess caffeine. Time-course profiles of the interlayer spacing and the uptake amount after injection of caffeine into the water slurry were obtained. At the initial period, the plot for the basal spacing was located above that for the adsorbed amount, suggesting that the rate of the interlayer spacing change was faster than that to attain the adsorption equilibrium. A first-order kinetic simulation fitted to the profile also indicates that the basal spacing included a rapid expansion of 0.08 nm within a few minutes and a slow expansion of 0.02 nm over several hours. Regarding the slow component, the rate constant for the basal spacing was lower than that for the amount of caffeine adsorbed, meaning that a steady-state basal spacing is reached after the adsorption equilibrium.
Polypropylene (PP) fibers have various excellent characteristics. However, it is difficult to use PP fibers for fashionable apparels due to its poor dyeing properties. Hence, in this paper, it has studied that developing a novel simple and inexpensive dyeing method for PP fibers by utilizing a cationic dye. It was developed that the PP dyeing method with the reduced form of a cationic dye, namely, leuco form. In the method, the permeability and affinity of the cationic dye for PP fibers would have been enhanced by reducing the cationic dye treated with a reducing agent in the alkaline aqueous solution. As a result, the reduced form of the cationic dye was adsorbed onto the PP fibers. Although, the color of the dye disappeared under an alkaline condition, the adsorbed cationic dye was recolored and fixed by treating with an oxidizing agent, and the dyed PP fibers were obtained. Following aforesaid method, the dyed PP fabrics were obtained by reducing the cationic dye with glucose under an alkaline condition at 100̊C and oxidizing it in an aqueous acetic acid solution at 50̊C. It was found that the L* of the dyed fabrics were low when Basic Blue 3, Basic Red 2, Basic Yellow 7, and Basic Orange 14 were used as a cationic dye.
In the anhydrate crystal of diammonium aquabis(malonato)oxidovanadate(IV), (NH4)2[VO(C3H2O4)2(H2O)], two conformers (syn or anti conformation on the equatorial plane) of complex cations are detected. The DFT calculations for the isomers indicate a slight influence of the conformation on their thermodynamic stability. The anionic complexes interact with adjacent anions and counter-cations through hydrogen bonds, and the hydrogen bonds lead to a structure with alternate stacking of layers consisting of either anti or syn isomers.
Bis(dialkylamino)phenoxazin-5-ium salts having different amino groups (dimethylamino, diethylamino, dipropylamino, dibutylamino, and pyrrolidyl) and counter anions (chloride, bromide, iodide, hydrogensulfate, and nitrate) were synthesized in up to 80% isolated yield as blue cationic dyes. In a d d i t i o n , 3 , 7 -b i s ( d i e t h y l a m i n o ) p h e n o t h i a z i n -5 -i u m a n d 3 , 7bis(diethylamino)phenoselenazin-5-ium iodides were also synthesized in 20% and 17% isolated yields, respectively. Polypropylene fabrics were dyed with the above synthesized blue cationic dyes. As an evaluation result, it has been found that the moderate size such as diethylamino groups at the 3 and 7 positions of phenoxazinium salts is suitable for the dyeing ability.
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