Adsorption of cysteine on metal(II) octacynaomolybdate(IV) at different pH values: Surface complexes characterization by FT-IR, SEM with EDXA, CHNS and Langmuir Isotherm analysis

2021 ◽  
pp. 118197
Author(s):  
Babita Saroha ◽  
Anand Kumar ◽  
Radha Raman Maurya ◽  
Manohar Lal ◽  
Sandeep Kumar ◽  
...  
Keyword(s):  
Langmuir Isotherm ◽  
Surface Complexes ◽  
Ph Values ◽  
Ft Ir

scholarly journals Thermal Transformation of Caffeic Acid on the Nanoceria Surface Studied by Temperature Programmed Desorption Mass-Spectrometry, Thermogravimetric Analysis and FT–IR Spectroscopy

2019 ◽  
Vol 3 (1) ◽  
pp. 34 ◽  
Author(s):  
Nataliia Nastasiienko ◽  
Borys Palianytsia ◽  
Mykola Kartel ◽  
Mats Larsson ◽  
Tetiana Kulik
Keyword(s):  
Mass Spectrometry ◽  
Thermogravimetric Analysis ◽  
Cerium Dioxide ◽  
Temperature Programmed Desorption ◽  
Hydroxyl Groups ◽  
Surface Complexes ◽  
Desorption Mass Spectrometry ◽  
Ft Ir ◽  
Temperature Programmed ◽  
Ft Ir Spectroscopy

The studies of pyrolysis of caffeic acid (CA) and its surface complexes is important for the development of technologies of heterogeneous catalytic pyrolysis of plant- and wood- based renewable biomass components. In this work, the structure and thermal transformations of the surface complexes of CA on the surface of nanoceria were investigated using Fourier transform–infrared (FT–IR) spectroscopy, thermogravimetric analysis (TGA) and temperature-programmed desorption mass spectrometry (TPD MS). It was found that CA on the surface of cerium dioxide forms several types of complexes: bidentate carboxylates, monodentate carboxylates and complexes formed as a result of interaction with phenolic hydroxyl groups. This is due to the ability of nanosized cerium dioxide to generate basic hydroxyl groups that can deprotonate phenolic groups to form phenolates on the surface. The main pyrolysis products were identified. The possible ways of forming 3,4-dihydroxyphenylethylene, acetylene carboxylic acid, pyrocatechol and phenol from surface complexes of CA were suggested. It was established that on the nanoceria surface effectively occur the decarboxylation, decarbonylation, and dehydration reactions of the CA, which are the desirable processes in biomass conversion technologies.

Synthesis of water-soluble conducting polypyrrole with transition-metal tetrasulfonated porphyrins

2010 ◽  
Vol 14 (02) ◽  
pp. 128-132 ◽  
Author(s):  
Mohammad Reza Nabid ◽  
Mitra Shamsianpour ◽  
Roya Sedghi ◽  
Samira Osati ◽  
Nasser Safari
Keyword(s):  
Transition Metal ◽  
Water Solubility ◽  
Water Soluble ◽  
Sulfonated Polystyrene ◽  
Salting Out ◽  
Electrically Conducting ◽  
Ph Values ◽  
Ft Ir ◽  
A Charge ◽  
Conducting Polypyrrole

A novel catalytic route for the synthesis of a water-soluble and electrically conducting polypyrrole (PPy) in the presence of sulfonated polystyrene (SPS) is presented. Anionic water-soluble transition-metal tetrasulfonated porphyrins (TSPP) were used to catalyze the polymerization. The reactions were carried out with different monomer, catalyst, template and initiator concentrations and the optimum conditions are reported. Also various pH values ranging from 1 to 4 were investigated. The absorbance of the polaron bands at different pH values demonstrates that pH 2 is the best condition for polymerization. Precipitation or "salting out" phenomenon was highly dependent on the mentioned factors. The formation of PPy was confirmed by UV-vis and FT-IR spectroscopy. Cyclic voltammetry (CV) showed that the synthesized polymer has convenient electroactivity. Furthermore, the presence of SPS that serves as a charge-compensating dopant in this complex provides a unique combination of properties such as processability and water solubility.

Aggregation, Isomerization and Thermo-Optic Property of Azobenzene Polyelectrolyte

2010 ◽  
Vol 123-125 ◽  
pp. 851-854 ◽  
Author(s):  
Feng Xian Qiu ◽  
Dong Ya Yang ◽  
Qing Zhang ◽  
Guo Rong Cao
Keyword(s):  
Thin Film ◽  
Optical Storage ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Inorganic Materials ◽  
Ph Values ◽  
Vis Spectroscopy ◽  
Optic Property ◽  
Ft Ir ◽  
Aggregation Behaviors

A novel azobenzene polyelectrolyte (ABAPE) was synthesized based on chromophore 4-(4’-nitrophenylazo) naphthol (NPAN), epoxychloropropane and α-methacrylic acid. The ABAPE was characterized by FT-IR and UV-vis spectroscopy. The aggregation behaviors of ABAPE were investigated based on different pH values by the UV-vis spectroscopy. The isomerization behavior of the ABAPE in DMAC solution was studied by 256 nm UV irradiation light. Attenuated total reflection (ATR) method was adopted and carried out the measurement of refractive index of the thin film. The thermo-optic coefficient (dn/dT) was -2.9228×10-4°C-1 and was bigger than inorganic materials such as silica glass, zinc silicate glass, borosilicate glass and the organic materials of polystyrene and PMMA. These results showed that the polyelectrolyte could be used to carry out optical storage and thermo-optic switch.

Adsorptive Removal of Ni(II) Ions from Aqueous Solution by Polyacrylic Acid/Attapulgite Composite Hydrogels

2017 ◽  
Vol 727 ◽  
pp. 859-865 ◽  
Author(s):  
Yi Wei Zheng ◽  
Wen Wen Tao ◽  
Gui Fang Zhang ◽  
Chao Lv ◽  
Yi Ping Zhao ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Polyacrylic Acid ◽  
Swelling Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorptive Removal ◽  
Composite Hydrogels ◽  
Ph Values ◽  
Ft Ir

Polyacrylic acid/attapulgite (PAA/ATP) composite hydrogels used for removal of heavy metal ions from aqueous solution was synthesized via radical polymerization with acrylic acid (AA) and attapulgite (ATP) modified by hydrochloric acid as adsorbent. Chemical composition of the modified ATP was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) and the morphology of the PAA/ATP hydrogels was characterized by scanning electron microscope (SEM), respectively. The swelling ratio, pH-sensitivity and adsorption performance of Ni (II) ions of the composite hydrogels were studied. The results showed the swelling ratio of the PAA/ATP composite hydrogels was higher than that of PAA hydrogels and the composite hydrogels displayed sensitivity to pH values with a sharp increase of swelling ratio when the pH values increased from 4 to 6. Comparing with PAA hydrogels, the composite hydrogels obtained a larger adsorption capacity of Ni (II) ions, the average adsorption capacity could reach 72.8 mg/g and adsorption ratio could reach 84%.

Aggregation and Photoresponsive Behavior of Polyelectrolyte

2010 ◽  
Vol 663-665 ◽  
pp. 645-649
Author(s):  
Feng Xian Qiu ◽  
Qing Zhang ◽  
Dong Ya Yang
Keyword(s):  
Optical Switch ◽  
Information Storage ◽  
Excitation Wavelength ◽  
Excellent Thermal Stability ◽  
Ph Values ◽  
Vis Spectroscopy ◽  
Potential Applications ◽  
Ft Ir ◽  
Responsive Behavior ◽  
Optical Information Storage

A novel polyelectrolyte (PLJY) was synthesized based on the azobenzene chromophore containing functional groups (-C=C-) and α-methacrylic acid by radical polymerization. The PLJY was characterized by FT-IR and UV-vis spectroscopy. The thermal property was characterized using the differential scanning calorimeter (DSC). The glass transition temperatures (Tg) was 179.1 oC and showed that the PLJY had excellent thermal stability. Influences of pH values on the UV-Vis absorption spectra of PLJY were studied and polyelectrolyte solution had good pH-sensitivity and H-aggregation behavior. The photoresponsive and thermochromism behaviors were investigated for the azo polyelectrolyte PLJY solution or film. By 256 nm excitation wavelength, the PLJY solution or film appeared photo responsive behavior. At high temperature, the PLJY solution had thermochromic behavior. These results showed that the polyelectrolyte had potential applications in optical information storage and optical switch.

Arsenic adsorption onto aluminium-substituted goethite

2016 ◽  
Vol 13 (5) ◽  
pp. 838 ◽  
Author(s):  
Ana E. Tufo ◽  
María dos Santos Afonso ◽  
Elsa E. Sileo
Keyword(s):  
Particle Surface ◽  
Oxide Surface ◽  
Surface Charges ◽  
Arsenic Adsorption ◽  
Surface Complexes ◽  
Al Content ◽  
Ph Values ◽  
Removal Capacity ◽  
Three Samples ◽  
Before And After

Environmental contextGoethite, commonly found in soils, is often partially substituted by Al and strongly influences the mobility of arsenic in the environment. The adsorption of AsV onto goethites with increasing Al substitution was explored, finding that Al incorporation decreases AsV sorption per gram of adsorbent, and that a low level of Al incorporation enhances the adsorption per unit area. Structures of the complexes formed between AsV and the oxy(hydr)oxide surface, at different pH values, are proposed by studying the changes in the surface charges of the adsorbed and non-adsorbed substituted and non-substituted goethites. AbstractAluminium and iron oxy(hydr)oxides in nature are often partially substituted by other elements and strongly influence the mobility of arsenic in the environment. Because goethite is commonly found in soils, and the oxide is easily substituted, in the present work, the adsorption of AsV onto several Al-substituted goethites was explored in order to determine how substitution affects the adsorption process. Three samples with increasing Al content (GAl0, GAl3.78 and GAl7.61) were prepared and fully characterised. The variations in AsV adsorption under different conditions, as well as the variations of the particle surface charge, were analysed. The results showed that the removal capacity of Al-goethites is determined by the Al content. The adsorption maxima per gram followed the trend GAl0> GAl3.78> GAl7.61, indicating that Al incorporation decreases AsV sorption. Adsorption per surface area decreased in the order GAl3.78> GAl0> GAl7.61, implying that a small incorporation of Al enhances the adsorption properties of the surface. The stoichiometry of the probable surface complexes formed with the contaminant at different pH values is proposed, by analysis of all the experimental results obtained before and after AsV adsorption. These surface complexes were used to fit the experimental data with good agreement, and the formation and acidity constants were also estimated.

Flocculation of Quaternary Chitosan on Acid Dyeing Waste Water

2013 ◽  
Vol 821-822 ◽  
pp. 531-534 ◽  
Author(s):  
De Hong Cheng ◽  
Jie Lin ◽  
Sheng Lu ◽  
Yan Hua Lu
Keyword(s):  
Waste Water ◽  
Ammonium Chloride ◽  
Heterogeneous Reaction ◽  
Acid Dye ◽  
Dyeing Wastewater ◽  
Solubility In Water ◽  
Chitosan Concentration ◽  
Ph Values ◽  
Ft Ir ◽  
Nucleophilic Center

In order to increase the positively charge, solubility in water and grafted degree of chitosan, quaternary chitosan was synthesized with chitosan and glycidyl-trimethyl-ammonium chloride by the heterogeneous reaction. FT-IR was used to characterize the structure of the synthesized. The quaternary chitosan was then used to treat simulated acid dyeing wastewater, the effect of quaternary chitosan concentration, agitation mode and pH values on flocculation were discussed. The results indicated that the H+in nucleophilic center-NH2was displaced by-CH2CH(OH)CH2N+(CH3)3and the 2-hydroxypropyltrimethyl ammonium chloride chitosan (quaternary chitosan) was synthesized. When applied to treatment of acid dye waste water, the decolorization rate was 95.5%, and the COD removal was 86.4%.

scholarly journals UV radiation and the reaction between ammonium and thiocyanate under prebiotic chemistry conditions

2010 ◽  
Vol 75 (10) ◽  
pp. 1381-1389 ◽  
Author(s):  
Santana de ◽  
Leidimara Pelisson ◽  
Diogo Janiaski ◽  
Cássia Zaia ◽  
Dimas Zaia
Keyword(s):  
Uv Radiation ◽  
Prebiotic Chemistry ◽  
Ammonium Thiocyanate ◽  
Nitrogen Atmosphere ◽  
Primitive Earth ◽  
Ph Values ◽  
Ft Ir ◽  
Uv Lamp ◽  
Hydrolysis Of ◽  
Ft Ir Spectroscopy

The reaction between ammonium and thiocyanate under prebiotic chemistry conditions was studied using FT-IR spectroscopy. Ammonium thiocyanate (1.0 10-3 mol L-1) was dissolved in sodium chloride solution (28.57 g L-1) at two different pH values (5.30 and 7.20). FT-IR results showed that it was possible that some compound that resembles dithiooxamides was synthesized when samples of ammonium thiocyanate were exposed to UV radiation under a regular atmosphere, as UV radiation in the presence of oxygen leads to the formation of perchlorate ions (ClO4-) due to the presence of Cl- ions as well. After acid hydrolysis of the samples of ammonium thiocyanate irradiated under a nitrogen atmosphere, yellow and white compounds were obtained, which could not be identified. These results were different from those reported in the literature, where other authors found methionine. However, they used higher concentrations of ammonium thiocyanate and a different type of UV lamp. On the other hand, in the present study, a lower concentration of ammonium thiocyanate was used, which probably resembled more the concentration of ammonium thiocyanate of primitive earth.

scholarly journals Adsorption Of Cd(II) Ions From Aqueous Solution By A Low-Cost Biosorbent Prepared From Ipomea Pes-Caprae Stem

2020 ◽  
Vol 9 (3) ◽  
pp. 197-206
Author(s):  
Thaharah Ramadhani ◽  
Faisal Abdullah ◽  
Indra Indra ◽  
Abrar Muslim ◽  
Suhendrayatna Suhendrayatna ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Optimal Condition ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Low Cost ◽  
Ph Values ◽  
Monolayer Adsorption ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ft Ir

The use of a low-cost biosorbent prepared from Ipomoea pes-caprae stem for the adsorption of Cd(II) ions from aqueous solution at different contact times, biosorbent sizes, pH values, and initial Cd(II) ions concentration solution was investigated. The biosorbent was analyzed using Fourier-transform infrared spectroscopy (FT-IR) to find important IR-active functional groups. A scanning electron microscope (SEM) was used to examine the biosorbent morphology. The experimental results showed the highest Cd(II) ions adsorption was 29.513 mg/g  under an optimal condition as initial Cd(II) ions concentration of 662.77 mg/L, 1 g dose, 80-min contact time, pH 5, 75 rpm of stirring speed, 1 atm, and 30 oC. Cd(II) ions' adsorption kinetics obeys the linearized pseudo-second-order kinetics (R2 = 0.996), and the adsorption capacity is based on the optimal condition, and the rate attained was 44.444 mg/g and 0.097 g/mg. Min, respectively. Besides, the adsorption isotherms were very well fitted by the linearized Langmuir isotherm model, and the monolayer adsorption capacity and pore volume determined was 30.121 mg/g and 0.129 L/mg, respectively. These results indicated the chemisorption nature

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