We report the hydrothermally enhanced hydrolysis of polyacrylonitrile (PAN) in neutral water, which generates photoluminescent polymers with low unsaturation degrees. Despite the hydrophobic nature of PAN, the product can be dissolved in water at a high concentration (≥100 g/L). The product exhibits complete absence of alkenes or aromatic structures, and photoluminescence originates from newly formed N-and O-containing groups. The presence of both n to π* and π to π* transitions is confirmed by time-dependent density functional theory (TD-DFT) calculations. The efficient transformation of PAN benefits from the enhanced hydrolysis of nitrile groups. While similar reactions have been reported previously under alkaline environments, we demonstrate that efficient hydrolysis can also occur in neutral water under the hydrothermal condition. Two additional methods based on different mechanisms are discussed to demonstrate the simplicity and efficiency of the hydrothermal reaction.

THE present work originated with the discovery by Rous, Gilding and Smith [1930] This paper deals only with the relative efficiency of azo dyes as anticoagulants and the relation between activity and chemical structure. One object in view was to find a dye which is anti-coagulant under all experimental conditions, inexpensive and does not render arterial and venous blood the same uniform "ink" colour as occurs with chlorazol sky blue FF.Many synthetic water-soluble direct dyes have pharmacological importance and are used in medicine. Such are trypan red [Ehrlich and Shiga, 1904] and trypan blue and afridol violet [Nicolle and Mesnil, 1906]. Subsequently germanin (Bayer 205) appeared. It is, however, not an azo compound. Stiiber and Lang [1930] showed that it has anti-coagulant action. In 1920 Harris suggested congo red as suitable for blood-volume determinations by the dye method. All these compounds like chlorazol sky blue FF have anti-coagulant properties.

Gemini salts of linear alkylbenzene sulfonate (LABS) were prepared by neutralization of sulfonic acid with a series of low-molecular-weight diamines in aqueous solution. The equilibrium surface activity of Gemini salts of LABS was determined by measuring the surface tension as a function of surfactant concentration to determine the critical micelle concentration (CMC), surface tension at the CMC (γ CMC ), and the area per molecule at the air-water interface (Å 2 ). Electrical conductivity was measured as a function of surfactant concentration to determine the CMC and counterion binding. Dynamic surface tension was measured using a bubble pressure tensiometer to infer the rate at which the surfactant migrates to the air-water interface. Equilibrium interfacial tension against mineral oil was measured using a spinning drop tensiometer. Dynamic interfacial tension was measured using a drop volume tensiometer. The surface tension, CMC, and interfacial tension of Gemini salts of LABS decreased compared to monovalent organic and inorganic salts. The CMC decreases with increasing molecular weight of the diamine spacer group. Dynamic surface and interfacial tension of Gemini salts of LABS are lower than monovalent salts. The foam volume of Gemini salts of LABS was determined using a high shear blender test. The foam volume of Gemini salts of LABS is lower than monovalent salts and depends on the size of the spacer group. Hard-surface cleaning was measured using artificial soil applied to white Formica tiles. Soil removal was determined by optical reflectance as a function of abrasion cycles. Gemini salts of LABS show reduced hard-surface cleaning performance compared to monovalent salts. Detergency of different types of soils on cotton and polyester/cotton fabric was determined by optical reflectance measurements. Gemini salts of LABS show improved cleaning performance compared to monovalent salts. Cleaning performance increases with increasing molecular weight of the diamine spacer group. In situ neutralization of LABS with organic diamines is a simple and efficient way to prepare anionic Gemini surfactants for industrial scale applications.

No abstract

No abstract