Chemical structure and surface activity. 10. The effect of hydroxyl group configuration on the adsorption of 2-alkyl-4-(hydroxymethyl)-1,3-dioxolanes and 2-alkyl-5-hydroxy-1,3-dioxanes at the aqueous solution-air interface

1985 ◽  
Vol 89 (6) ◽  
pp. 1032-1035 ◽  
Author(s):  
Bogdan Burczyk ◽  
Andrzej Piasecki ◽  
Ludmila Weclas
Keyword(s):  
Aqueous Solution ◽  
Surface Activity ◽  
Chemical Structure ◽  
Hydroxyl Group ◽  
Air Interface ◽  
Group Configuration

scholarly journals Reactivity of Aliphatic and Phenolic Hydroxyl Groups in Kraft Lignin towards 4,4′ MDI

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2131
Author(s):  
Leonardo Dalseno Antonino ◽  
Júlia Rocha Gouveia ◽  
Rogério Ramos de Sousa Júnior ◽  
Guilherme Elias Saltarelli Garcia ◽  
Luara Carneiro Gobbo ◽  
...  
Keyword(s):  
Experimental Work ◽  
Chemical Structure ◽  
31P Nmr ◽  
Kraft Lignin ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Diphenylmethane Diisocyanate ◽  
Complex Chemical ◽  
Heterogeneous Reactivity ◽  
Phenolic Hydroxyl Groups

Several efforts have been dedicated to the development of lignin-based polyurethanes (PU) in recent years. The low and heterogeneous reactivity of lignin hydroxyl groups towards diisocyanates, arising from their highly complex chemical structure, limits the application of this biopolymer in PU synthesis. Besides the well-known differences in the reactivity of aliphatic and aromatic hydroxyl groups, experimental work in which the reactivity of both types of hydroxyl, especially the aromatic ones present in syringyl (S-unit), guaiacyl (G-unit), and p-hydroxyphenyl (H-unit) building units are considered and compared, is still lacking in the literature. In this work, the hydroxyl reactivity of two kraft lignin grades towards 4,4′-diphenylmethane diisocyanate (MDI) was investigated. 31P NMR allowed the monitoring of the reactivity of each hydroxyl group in the lignin structure. FTIR spectra revealed the evolution of peaks related to hydroxyl consumption and urethane formation. These results might support new PU developments, including the use of unmodified lignin and the synthesis of MDI-functionalized biopolymers or prepolymers.

scholarly journals Trimethylamine-N-oxide: its hydration structure, surface activity, and biological function, viewed by vibrational spectroscopy and molecular dynamics simulations

2017 ◽  
Vol 19 (10) ◽  
pp. 6909-6920 ◽  
Author(s):  
Tatsuhiko Ohto ◽  
Johannes Hunger ◽  
Ellen H. G. Backus ◽  
Wataru Mizukami ◽  
Mischa Bonn ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Aqueous Solution ◽  
Molecular Dynamics Simulations ◽  
Surface Activity ◽  
Vibrational Spectroscopy ◽  
Biological Function ◽  
Molecular Simulations ◽  
Structure Surface ◽  
Dynamics Simulations ◽  
Hydrophilicity And Hydrophobicity

Vibrational spectroscopy and molecular simulations revealed the hydrophilicity and hydrophobicity of TMAO in aqueous solution.

scholarly journals Synthesis of Zeolite from Carbothermal Reduction Electrolytic Manganese Residue for the Removal of Macrolide Antibiotics from Aqueous Solution

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2133 ◽  
Author(s):  
Xuli Li ◽  
Yue Zeng ◽  
Fangyuan Chen ◽  
Teng Wang ◽  
Yixin Li ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Carbothermal Reduction ◽  
Adsorption Process ◽  
Hydroxyl Group ◽  
Macrolide Antibiotics ◽  
Adsorption Sites ◽  
Electrolytic Manganese ◽  
Electrolytic Manganese Residue ◽  
Pseudo Second Order ◽  
The Fourier Transform

Zeolite analcime (EMANA) was synthesized through the hydrothermal method by using carbothermal reduction electrolytic manganese residue (CR-EMR). The structural properties of EMANA and CR-EMR were studied using various characterization techniques. After hydrothermal synthesis, the CR-EMR became super-microporous, and the surface area increased by 4.76 times than before. Among the various synthesized zeolites, 6 h-synthesized EMANA was selected as the best adsorbent for macrolide antibiotics in aqueous solution. The adsorption performance of EMANA on the adsorption capacity was examined by using various experimental parameters, such as contact time (0–24 h), initial concentration (50–300 mg/L), temperature (30–50 °C) and pH (3–13). The experimental results were also analyzed by the Langmuir and Freundlich adsorption models, with the latter obtaining better representation. The adsorption process could be described well by the pseudo-second-order model, even under a low concentration (50 mg/L). This result suggests that the adsorption process of macrolide antibiotics is due to chemisorption. According to the Fourier Transform infrared spectroscopy (FT-IR) results, the adsorption of zeolite was mainly due to its hydroxyl group, which played an important role during the adsorption process. Moreover, EMANA is more suitable for treatment of roxithromycin (ROX) than azithromycin (AZM), because ROX has more adsorption sites for the hydroxyl group.

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