Vol 481, No 1 (2018)

A new synthetic route was developed to three-module type potential hydrophobic agents, with the molecule consisting of an N-[3-(triethoxysilyl)propyl]amide anchor part (I), a connecting unit formed upon 1,3-propansultone ring cleavage (II), and a polyfluoroheptyloxy functional hydrophobic spacer (III). Proceeding from commercially available polyfluorinated heptanols 1a and 1b and 1,3-propanesultone 3, potassium sulfonates 4a and 4b were prepared. The reaction of 4a and 4b with phosphorus oxychloride resulted in the first synthesis of fluorine-containing sulfonyl chlorides 5a and 5b, which were reacted with 3-aminopropyltriethoxysilane 6 to give the target N-[3-(triethoxysilyl)propyl]-3-(polyfluoroheptyloxy)propane-1-sulfonamides 7a and 7b. The structures of the compounds were proved by NMR spectroscopy, mass spectrometry, and elemental analysis. The studies of their hydrophobizing properties are in progress.

A new method was proposed to increase the crystallization rate in growing single crystals of quartz. In this method, the crystallization is accelerated by using surfactants (polyethyleneamine, tetramethylammonium base, and polyethyleneimine) added to a soda-alkaline solution of standard concentration. Within studied ranges of pressures and concentrations of components of the solution, polyethyleneimine at a concentration of 0.002–0.05 wt % is the most efficient crystallization accelerator, which can increase the quartz crystal growth rate on the average by a factor of 2.

The bisulfate process is promising for the development of closed cycle technologies for the processing of alumina-containing raw materials with reagent recovery. Implementing this process requires a rational method for separation of ammonium bisulfate into the sulfate and sulfuric acid in each cycle. The possibility of such separation was shown for the first time by modification of the acid retardation technique based on the sieve effect in the nanoporous medium. The proposed method solves the problem of reagent recovery, which is relevant for some industrial processes, and has prospects for the development of new ore processing techniques.