scholarly journals Quaternary-ammonium-immobilized polystyrenes as efficient and reusable heterogeneous catalysts for synthesis of cyclic carbonate: Effects of linking chains and pendent hydroxyl group

2017 ◽  
Vol 38 (5) ◽  
pp. 862-871 ◽  
Author(s):  
Xiaoming Yan ◽  
Xuan Ding ◽  
Yu Pan ◽  
Xiaowei Xu ◽  
Ce Hao ◽  
...  
RSC Advances ◽  
2016 ◽  
Vol 6 (3) ◽  
pp. 2217-2224 ◽  
Author(s):  
Qingyuan Deng ◽  
Gaohong He ◽  
Yu Pan ◽  
Xuehua Ruan ◽  
Wenji Zheng ◽  
...  

Novel bis-ammonium immobilized polystyrenes with co-catalyzing functional groups were prepared for efficient synthesis of cyclic carbonate from CO2 and epoxides.


RSC Advances ◽  
2017 ◽  
Vol 7 (5) ◽  
pp. 2836-2841 ◽  
Author(s):  
Tao Wang ◽  
Wenlong Wang ◽  
Yuan Lyu ◽  
Xingkun Chen ◽  
Cunyao Li ◽  
...  

A series of cross-linked polymer supported ionic liquids based on quaternary ammonium salts have been prepared using a facile method of radical polymerization.


2017 ◽  
Vol 19 (24) ◽  
pp. 16047-16056 ◽  
Author(s):  
Xuepeng Wu ◽  
Caili Dai ◽  
Sisi Fang ◽  
Hao Li ◽  
Yining Wu ◽  
...  

The influence of the introduction of a hydroxyl group into the system is studied at the macro and micro levels.


2011 ◽  
Vol 311-313 ◽  
pp. 2067-2070
Author(s):  
Fei Zhou ◽  
Jing Zheng

Quaternary ammonium compounds, Couple, Cotton fiber, Antibacterial activity. Abstract. a gemini-type quaternary ammonium compound with a hydroxyl group in their spacer chain, 4,5-bis(dodecyl dimethyl ammonium bromide)-1-pentanol (called as DAP12), was immobilized on the surface of cotton fiber by using a silane coupler, tetraethoxysilane and a novel antibacterial cotton fiber (called as CF12) was prepared. Antibacterial characteristics of CF12 were investigated comparatively with [3-(trimethoxysilyl) propyl] octadecyldimethylammonium chloride(TPOAC), a mono-type quaternary ammonium salt. CF12 had excellent antibacterial characteristics in the wide range of environmental pH and temperature, which is not weakened even if 30 times repetitive use. The experimental results indicated also that CF12 has higher antimicrobial activity than TPOAC immobilized on the surface of cotton fiber against a broad range of microorganisms, and average inhibition ratio against 15 strains of gram-negative, gram-positive bacteria and yeasts is 99.0% at 30 °C and pH 6.0.


2019 ◽  
Vol 3 (4) ◽  
pp. 935-941 ◽  
Author(s):  
Tanmoy Biswas ◽  
Venkataramanan Mahalingam

An ionic liquid-triazine and KI combination was found to be an efficient catalyst for epoxide to cyclic carbonate conversion under CO2 filled balloon conditions.


Ecotoxicology ◽  
2021 ◽  
Author(s):  
Ewa Liwarska-Bizukojc ◽  
Christian V. Stevens ◽  
Elisabeth I. P. Delbeke ◽  
Kevin M. Van Geem

AbstractA new class of biosurfactants, namely quaternary ammonium sophorolipids (SQAS), suitable for pharmaceutical applications, was tested for the evaluation of their (anti)estrogenic and (anti)androgenic potency with the help of YES/YAS assays. Also their toxicity towards yeasts (Saccharomyces cerevisiae) and bacteria (Escherichia coli) was checked. The results achieved for SQAS, which can be regarded as potential micropollutants, were compared with those obtained for two well-known micropollutants diclofenac and 17α-ethinylestradiol subjected to the same testing procedures. This work demonstrated that acetylation of the hydroxyl group of the carbohydrate head of SQAS decreased the toxicity of this class of biosurfactants towards Saccharomyces cerevisiae. Furthermore, it contributed to the decrease of their endocrine disrupting potency. None of the SQAS studied showed clear agonist activity for female or male hormones. SQAS1 and SQAS2 revealed weak antiestrogenic and antiandrogenic potency. All of these properties were weaker, not only to the potency of the appropriate positive control in the antagonists bioassays, but also compared to the potency of other tested compounds, i.e. DCF and EE2. SQAS3 possessed most probably inhibitory activity towards male hormones. Moreover, cytotoxicity of two out of four studied SQAS at the highest concentrations towards the strains of Saccharomyces cerevisiae interfered with the endocrine disruption activity. It would be also worth studying it with the use of another endocrine activity test.


2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Li Chang ◽  
Wenjie Duan ◽  
Siqi Huang ◽  
Anguo Chen ◽  
Jianjun Li ◽  
...  

In this study, a novel antibacterial hemp fibre grafted with quaternary ammonium groups (HF–GTA), were prepared by alkalization, oxidation, amination and quaternization multistage reactions. The chemical structure and micromorphology of the fibre were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis and X-ray diffraction. The grafting and reaction mechanism proved to be successful, which indicated that the grafting reaction primarily occurred on the hydroxyl group of cellulose and hemicellulose in the hemp fibre, where it retained good fibrous morphology, thermal stability and hygroscopicity. HF–GTA exhibited the best antibacterial activity, where the antibacterial ratios against Escherichia coli and Staphylococcus aureus were 95.41% and 99.64%, respectively. Even after washing 30 times, the antibacterial activity was retained at 89.78% and 91.12%, indicating that HF–GTA was endowed with good washing resistance. The antibacterial activity was owing to the electrostatic reaction reducing the electrochemical potential on the cell membrane, leading to the release of cytoplasmic substances and the dissolution of cells. This study is significantly important for guaranteeing textile quality and preventing disease transmission.


RSC Advances ◽  
2017 ◽  
Vol 7 (24) ◽  
pp. 14721-14732 ◽  
Author(s):  
Kun Li ◽  
Xiaohui Wu ◽  
Qingwen Gu ◽  
Xiuge Zhao ◽  
Mingming Yuan ◽  
...  

The inclusion complexes between β-cyclodextrin and 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU)-based phenolates have been developed and employed as heterogeneous catalysts for the cycloaddition of CO2 to cyclic carbonate.


2020 ◽  
Vol 356 ◽  
pp. 527-534
Author(s):  
Doyun Kim ◽  
Saravanan Subramanian ◽  
Damien Thirion ◽  
Youngdong Song ◽  
Aqil Jamal ◽  
...  

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