scholarly journals SYNTHETIC POLYAMPHOLYTE HYDROGELS BASED ON VARIOUS ALIPHATIC DIAMINS FOR REMOVING DYES FROM AQUEOUS SOLUTIONS

2020 ◽  
pp. 149-158
Author(s):  
Вадим Аполлонович Липин ◽  
Андрей Николаевич Евдокимов ◽  
Татьяна Александровна Суставова ◽  
Юлия Александровна Петрова
Keyword(s):  
Crosslinking Agent ◽  
Weak Acid ◽  
High Chemical ◽  
Strong Base ◽  
Ph Values ◽  
Wide Range ◽  
Scope Of Application ◽  
Initiator System ◽  
Aliphatic Diamines ◽  
Hydrolyzed Polyacrylamide

Были исследованы полиамфолитные гидрогели, полученные на основе частично гидролизованного полиакриламида и алифатических диаминов (этилендиамина, 1,3-диаминопропана и 1,4-диаминобутана) без использования инициирующей системы и сшивающего агента. Использованные азотсодержащие мономеры, обладая высокой химической активностью, осуществляют химическую сшивку получаемых полиамфолитных гидрогелей. Было установлено, что полиамфолиты, полученные из сильного основания и слабой кислоты, теряют свою чувствительность к рН и ионной силе из-за несбалансированности заряженных функциональных групп, что расширяет области применения полиамфолитных гидрогелей в различных областях промышленности, где в течение процесса значения рН и содержание электролитов могут меняться. Полученные полиамфолитные гидрогели на основе различных алифатических диаминов могут быть использованы в качестве сорбционных материалов для удаления окрашенных примесей и могут применяться в широком диапазоне значений рН. Polyampholytic hydrogels based on partially hydrolyzed polyacrylamide and aliphatic diamines (ethylenediamine, 1,3-diaminopropane, and 1,4-diaminobutane) without using an initiator system and a crosslinking agent was studied. The used nitrogen-containing monomers, possessing high chemical activity, carry out chemical crosslinking of the obtained polyampholytic hydrogels. It was found that polyampholytes obtained from a strong base and a weak acid lose their sensitivity to pH and ionic strength due to the imbalance of charged functional groups, which expands the scope of application of polyampholyte hydrogels in various industries, where during the process the pH values and electrolyte content can change. The obtained polyampholytic hydrogels based on various aliphatic diamines can be used as sorption materials to remove colored impurities and can be used in a wide range of pH values.

Nitrogen Removal from Anaerobically-Treated Leachate

1984 ◽  
Vol 19 (1) ◽  
pp. 87-100
Author(s):  
D. Prasad ◽  
J.G. Henry ◽  
P. Elefsiniotis
Keyword(s):  
Nitrogen Removal ◽  
Air Flow ◽  
Operating Conditions ◽  
Air Flow Rate ◽  
Flow Rates ◽  
Anaerobic Filter ◽  
Ph Values ◽  
Wide Range ◽  
Ammonia Desorption ◽  
Effects Of Ph

Abstract Laboratory studies were conducted to demonstrate the effectiveness of diffused aeration for the removal of ammonia from the effluent of an anaerobic filter treating leachate. The effects of pH, temperature and air flow on the process were studied. The coefficient of desorption of ammonia, KD for the anaerobic filter effluent (TKN 75 mg/L with NH3-N 88%) was determined at pH values of 9, 10 and 11, temperatures of 10, 15, 20, 30 and 35°C, and air flow rates of 50, 120, and 190 cm3/sec/L. Results indicated that nitrogen removal from the effluent of anaerobic filters by ammonia desorption was feasible. Removals exceeding 90% were obtained with 8 hours aeration at pH of 10, a temperature of 20°C, and an air flow rate of 190 cm3/sec/L. Ammonia desorption coefficients, KD, determined at other temperatures and air flow rates can be used to predict ammonia removals under a wide range of operating conditions.

scholarly journals Hybrid Acrylated Chitosan and Thiolated Pectin Cross-Linked Hydrogels with Tunable Properties

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 266
Author(s):  
Shaked Eliyahu ◽  
Alexandra Galitsky ◽  
Esther Ritov ◽  
Havazelet Bianco-Peled
Keyword(s):  
Electrostatic Interactions ◽  
Profile Analysis ◽  
Hybrid Hydrogel ◽  
Texture Profile ◽  
Ph Values ◽  
X Ray Scattering ◽  
Wide Range ◽  
Michael Type Addition ◽  
Physical And Chemical ◽  
Hydrogel System

We developed and characterized a new hydrogel system based on the physical and chemical interactions of pectin partially modified with thiol groups and chitosan modified with acrylate end groups. Gelation occurred at high pectin thiol ratios, indicating that a low acrylated chitosan concentration in the hydrogel had a profound effect on the cross-linking. Turbidity, Fourier transform infrared spectroscopy, and free thiol determination analyses were performed to determine the relationships of the different bonds inside the gel. At low pH values below the pKa of chitosan, more electrostatic interactions were formed between opposite charges, but at high pH values, the Michael-type addition reaction between acrylate and thiol took place, creating harder hydrogels. Swelling experiments and Young’s modulus measurements were performed to study the structure and properties of the resultant hydrogels. The nanostructure was examined using small-angle X-ray scattering. The texture profile analysis showed a unique property of hydrogel adhesiveness. By implementing changes in the preparation procedure, we controlled the hydrogel properties. This hybrid hydrogel system can be a good candidate for a wide range of biomedical applications, such as a mucosal biomimetic surface for mucoadhesive testing.

scholarly journals In Vitro Incorporation of Helicobacter pylori into Candida albicans Caused by Acidic pH Stress

Pathogens ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 489 ◽  
Author(s):  
Kimberly Sánchez-Alonzo ◽  
Cristian Parra-Sepúlveda ◽  
Samuel Vega ◽  
Humberto Bernasconi ◽  
Víctor L. Campos ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Candida Albicans ◽  
Pcr Amplification ◽  
Growth Curves ◽  
Acidic Ph ◽  
Ph Values ◽  
16S Gene ◽  
Wide Range ◽  
H Pylori

Yeasts can adapt to a wide range of pH fluctuations (2 to 10), while Helicobacter pylori, a facultative intracellular bacterium, can adapt to a range from pH 6 to 8. This work analyzed if H. pylori J99 can protect itself from acidic pH by entering into Candida albicans ATCC 90028. Growth curves were determined for H. pylori and C. albicans at pH 3, 4, and 7. Both microorganisms were co-incubated at the same pH values, and the presence of intra-yeast bacteria was evaluated. Intra-yeast bacteria-like bodies were detected using wet mounting, and intra-yeast binding of anti-H. pylori antibodies was detected using immunofluorescence. The presence of the H. pylori rDNA 16S gene in total DNA from yeasts was demonstrated after PCR amplification. H. pylori showed larger death percentages at pH 3 and 4 than at pH 7. On the contrary, the viability of the yeast was not affected by any of the pHs evaluated. H. pylori entered into C. albicans at all the pH values assayed but to a greater extent at unfavorable pH values (pH 3 or 4, p = 0.014 and p = 0.001, respectively). In conclusion, it is possible to suggest that H. pylori can shelter itself within C. albicans under unfavorable pH conditions.

Dyeing Properties of Chitosan-Sulfamic Acid Solution Treated Wool with Silane Coupling Agent

2011 ◽  
Vol 331 ◽  
pp. 377-381 ◽  
Author(s):  
Xue Mei He ◽  
Kong Liang Xie
Keyword(s):  
Low Temperature ◽  
Acid Solution ◽  
Crosslinking Agent ◽  
Sulfamic Acid ◽  
Weak Acid ◽  
Color Strength ◽  
Surface Appearance ◽  
Wool Fabrics ◽  
Wool Fibers ◽  
Higher Temperature

In this study, wool fabrics were treated with different concentration of chitosan sulfamic acid solution under using 3-glycidyloxypropyltrimethoxysilane (GPTMS) as a crosslinking agent. The structure of treated wool fabrics was investigated by SEM, DSC-TG. Treated wool fibers had a irregular surface appearance, showed the presence of amounts of Nano SiO2 and their aggregates deposited onto surface of wool fibers. The thermal properties were obviously enhanced. Treated wool fabrics is more stable in higher temperature than that of untreatment. Treated wool fabrics were dyed with weak acid red B, and dyeing behaviour were studied by means of by light reflectance measurements. The color strength (K/S value) of treated wool fabrics obviousily increased from 5.33 to 31.68 by comparison with the untreatment. As a result, it can be concluded that the chitosan sulfamic acid solution with GPTMS treatment could improve the weak acid red B low temperature dyeing on wool. Further, low temperature dyeing of wool fabrics with chitosan-sulfamic acid is safe, so the results obtained are quite promising as a basis for possible future industrial application.

scholarly journals Synthesis of Novel Crosslinked Chitosans with a Higher Fatty Diacid Diglycidyl and Their Adsorption Abilities towards Acid Dyes

2003 ◽  
Vol 21 (5) ◽  
pp. 439-449 ◽  
Author(s):  
Yoshiaki Shimizu ◽  
Atsushi Taga ◽  
Hitoshi Yamaoka
Keyword(s):  
Chemical Structure ◽  
Crosslinking Agent ◽  
Considerable Extent ◽  
Degree Of Substitution ◽  
Acid Orange 7 ◽  
Acid Dyes ◽  
Ph Values ◽  
Crosslinked Chitosan ◽  
Adsorbent Materials ◽  
Dye Molecule

Novel chitosan-based adsorbent materials with a higher fatty diacid diglycidyl as the crosslinking agent were synthesized and the adsorption abilities of the resulting polymers evaluated towards typical acid dyes. The successful formation of a crosslinked structure was confirmed via infrared spectroscopic measurements and the solubility of the polymer towards 10% aqueous solutions of acetic and formic acids determined. At higher dye concentrations, the adsorption abilities of the crosslinked chitosan towards hydrophilic CI Acid Orange 7 and CI Acid Red 1 increased with decreasing degree of substitution. However, at lower dye concentrations, the crosslinked chitosan with the lowest degree of substitution exhibited the lowest adsorption capability. With such hydrophilic acid dyes, the extent of adsorption decreased significantly as the pH of the solution increased. On the other hand, CI Acid Red 138, which contains a dodecyl group in the chemical structure, was adsorbed to a considerable extent even at higher pH values, suggesting hydrophobic interaction between the alkyl group in the dye molecule and the hydrophobic crosslinker.

Two-Color Probe to Monitor a Wide Range of pH Values in Cells

2013 ◽  
Vol 52 (24) ◽  
pp. 6206-6209 ◽  
Author(s):  
Min Hee Lee ◽  
Ji Hye Han ◽  
Jae Hong Lee ◽  
Nayoung Park ◽  
Rajesh Kumar ◽  
...  
Keyword(s):  
Ph Values ◽  
Wide Range ◽  
In Cells

scholarly journals Phosphatase synthesis in Klebsiella (Aerobacter) aerogenes growing in continuous culture

1972 ◽  
Vol 127 (1) ◽  
pp. 87-96 ◽  
Author(s):  
P. G. Bolton ◽  
A. C. R. Dean
Keyword(s):  
Alkaline Phosphatase ◽  
Acid Phosphatase ◽  
Continuous Culture ◽  
Activity Profile ◽  
Glucose Effect ◽  
Ph Values ◽  
Nitrophenyl Phosphate ◽  
Wide Range ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

1. Phosphatase synthesis was studied in Klebsiella aerogenes grown in a wide range of continuous-culture systems. 2. Maximum acid phosphatase synthesis was associated with nutrient-limited, particularly carbohydrate-limited, growth at a relatively low rate, glucose-limited cells exhibiting the highest activity. Compared with glucose as the carbon-limiting growth material, other sugars not only altered the activity but also changed the pH–activity profile of the enzyme(s). 3. The affinity of the acid phosphatase in glucose-limited cells towards p-nitrophenyl phosphate (Km 0.25–0.43mm) was similar to that of staphylococcal acid phosphatase but was ten times greater than that of the Escherichia coli enzyme. 4. PO43−-limitation derepressed alkaline phosphatase synthesis but the amounts of activity were largely independent of the carbon source used for growth. 5. The enzymes were further differentiated by the effect of adding inhibitors (F−, PO43−) and sugars to the reaction mixture during the assays. In particular, it was shown that adding glucose, but not other sugars, stimulated the rate of hydrolysis of p-nitrophenyl phosphate by the acid phosphatase in carbohydrate-limited cells at low pH values (<4.6) but inhibited it at high pH values (>4.6). Alkaline phosphatase activity was unaffected. 6. The function of phosphatases in general is discussed and possible mechanisms for the glucose effect are outlined.

Efficient degradation of tetracycline by H2O2 catalyzed by FeOCl: A wide range of pH values from 3 to 7

2021 ◽  
Vol 113 ◽  
pp. 106548
Author(s):  
Yong Cao ◽  
Kangping Cui ◽  
Yihan Chen ◽  
Minshu Cui ◽  
Guanghong Li ◽  
...  
Keyword(s):  
Ph Values ◽  
Wide Range

A novel 3D Zn-coordination polymer based on a multiresponsive fluorescent sensor demonstrating outstanding sensitivities and selectivities for the efficient detection of multiple analytes

2021 ◽  
Author(s):  
Yu Liu ◽  
Yan Wang ◽  
Xiao-Sa Zhang ◽  
Yu-Shu Sheng ◽  
Wen-Ze Li ◽  
...  
Keyword(s):  
Detection Limit ◽  
Coordination Polymer ◽  
Fluorescent Sensor ◽  
Lower Detection Limit ◽  
Ph Values ◽  
Efficient Detection ◽  
Wide Range ◽  
Lower Detection ◽  
Multiple Analytes

A Zn-CP exhibits remarkable fluorescence behaviours and stability in a wide range of pH values. It can become an outstanding candidate in the selective sensing of Fe3+, Mg2+, Cr2O72−, MnO4−, NB and NM at a lower detection limit.

scholarly journals Analyses of Total Alkaloid Extract ofCorydalis yanhusuoby Comprehensive RP × RP Liquid Chromatography with pH Difference

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaodong Wei ◽  
Hongling Shen ◽  
Lijun Wang ◽  
Qingyan Meng ◽  
Wenjie Liu
Keyword(s):  
Liquid Chromatography ◽  
Total Alkaloid ◽  
Ph Value ◽  
Ammonium Hydroxide ◽  
Peak Capacity ◽  
Strong Base ◽  
Retention Factors ◽  
Ph Values ◽  
Dimension Analysis ◽  
Alternative Approach

A comprehensive two-dimensional (2D) reverse phase (RP) liquid chromatography (LC) method is developed for alkaloid analysis. This offline comprehensive 2D method is developed using different pH values. With a pH value of 10.5, most alkaloids appear in the form of neutral molecules possessing high retention factors based on their polarity, while the alkaloid polarity order is changed when the pH value decreased to 3.0. The performance of pH modulated 2D LC is demonstrated with 8 alkaloid standards which resulted in orthogonal separation. The developed method is then applied to total alkaloid separation inCorydalis yanhusuo. The first-dimension separation is carried out using methanol and water containing 1.0% ammonium hydroxide and a strong base-resistant RP column, which afforded a peak capacity of 94. The second-dimension analysis is carried out with a surface positive charge column providing a peak capacity of 205 using a mobile phase consisting of acetonitrile and water with 0.15% formic acid. 2D analyses of total alkaloid extract fromC. yanhusuoafford a total peak capacity of 9090. Sixteen compounds were tentatively identified based on their ultraviolet spectrum and MS/MS analyses. The proposed method provides an alternative approach to achieve high peak capacity for analysis of alkaloid extract.

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