25727-93-9Relevant articles and documents
Evaluation of a novel morpholine-typed Gemini surfactant as the collector for the reverse flotation separation of halite from carnallite ore
Ai, Guanghua,Cheng, Chen,Fu, Weng,Guo, Zhiqun,He, Guichun,Huang, Zhiqiang,Liu, Rukuan,Liu, Zuwen,Wang, Hongling,Yu, Xinyang,Zhang, Feng,Zhang, Shiyong,Zhou, Jianrong
, (2020)
In froth flotation separation process, the collector molecular design has a crucial effect on potash processing to ensure sustainable production of potassium fertilizer (KCl) that is important to secure food supply in human society. Carnallite is an important source of KCl fertilizer production in industry. Reverse flotation has been used to separate halite (NaCl) impurities from carnallite (KCl·MgCl2·6H2O) for carnallite resources. However, progress in the carnallite resource reverse froth flotation has been constrained by the inherent limitation of traditional collector molecules with a single hydrophilic head and single hydrophobic chain per molecule. Herein, a novel morpholine-based Gemini molecule with double hydrophilic heads and hydrophobic chains, butanediyl-α, ω-bis (morpholino tetradecylammonium bromide) (BMTB) was synthesized and applied as the flotation collector in the reverse flotation separation for carnallite mineral. The better flotation performance of Gemini BMTB was achieved, compared to the traditional monomeric surfactant N-(n-Tetradecyl) morpholine (TDM). The bench-scale froth flotation separation results revealed that BMTB exhibited outstanding affinity and selectivity for NaCl crystals from carnallite at natural pH, resulting in less collector dosages – only 1/3 of TDM molecules. In contrast with traditional monomeric surfactant TDM (120 g/t), less amount of Gemini BMTB (40 g/t) – only one third of TDM molecules, was needed to obtain higher KCl recovery (KCl recovery raised by 4.69%). Meanwhile, the grade of NaCl with 40 g/t BMTB collector (2.19%) was lower than that with 120 g/t TDM collector (3.91%), and the grade of KCl with BMTB collector (22.59%) was higher than that with TDM collector (22.12%). Therefore, this work demonstrated the next-generation of flotation collector for the reverse froth flotation separation of the carnallite resources.
Alkylated Piperazines and Piperazine-Azole Hybrids as Antifungal Agents
Thamban Chandrika, Nishad,Shrestha, Sanjib K.,Ngo, Huy X.,Tsodikov, Oleg V.,Howard, Kaitlind C.,Garneau-Tsodikova, Sylvie
, p. 158 - 173 (2018/02/10)
The extensive use of fluconazole (FLC) and other azole drugs has caused the emergence and rise of azole-resistant fungi. The fungistatic nature of FLC in combination with toxicity concerns have resulted in an increased demand for new azole antifungal agents. Herein, we report the synthesis and antifungal activity of novel alkylated piperazines and alkylated piperazine-azole hybrids, their time-kill studies, their hemolytic activity against murine erythrocytes, as well as their cytotoxicity against mammalian cells. Many of these molecules exhibited broad-spectrum activity against all tested fungal strains, with excellent minimum inhibitory concentration (MIC) values against non-albicans Candida and Aspergillus strains. The most promising compounds were found to be less hemolytic than the FDA-approved antifungal agent voriconazole (VOR). Finally, we demonstrate that the synthetic alkylated piperazine-azole hybrids do not function by fungal membrane disruption, but instead by disruption of the ergosterol biosynthetic pathway via inhibition of the 14α-demethylase enzyme present in fungal cells.
