scholarly journals A simple multi‐wavelength spectroscopic method for the determination of carboxyl group content in nanocellulose

Cellulose ◽  
2021 ◽  
Author(s):  
Ning Yan ◽  
Xin-Sheng Chai ◽  
Troy Runge
Keyword(s):  
Spectroscopic Method ◽  
Reference Method ◽  
Small Sample ◽  
Carboxyl Groups ◽  
Solution Technique ◽  
Carboxyl Group ◽  
Group Content ◽  
Multi Wavelength ◽  
Carboxyl Group Content

AbstractThis study describes a multi-wavelength spectroscopic method for the determination of carboxyl group content of nanocellulose. Methylene blue (MB) was used as a color indicator, which can bind to the carboxyl groups in nanocellulose to form a R-COOMB complex with a binding ratio of 1:1, although the spectrums of MB and R-COOMB at 500–750 nm are overlapped, and solid impurities could cause spectral interference. To solve these issues, a multi-wavelength spectroscopic measurement on a MB and nanocellulose mixture solution technique and mathematical model were developed, allowing the content of carboxyl groups in nanocellulose to be quantified. The results showed that the method has good measurement precision and accuracy as compared with those measured by a reference method. The method is simple and requires only a small sample size for testing and thus makes it suitable for nanocellulose related research and applications.

scholarly journals PREPARATION OF FLUORESCENT POLYSTYRENE MICROSPHERES BY IMPROVING SWELLING PERFORMANCE BASED ON MOLECULAR WEIGHT AND SURFACE CARBOXYL GROUP CONTENT

Química Nova ◽  
2021 ◽  
Author(s):  
Fei Sun ◽  
Chao Feng ◽  
Yang Wang ◽  
Xue Yang ◽  
Hong Zhao
Keyword(s):  
Molecular Weight ◽  
Carboxyl Group ◽  
Polystyrene Microspheres ◽  
Doping Amount ◽  
Fluorescent Microspheres ◽  
Related Factors ◽  
Fluorescent Substance ◽  
Swelling Properties ◽  
Group Content ◽  
Carboxyl Group Content

The fluorescent microspheres are prepared by the swelling-evaporation method. The optimal swelling conditions are obtained by researching related factors, such as types and dosages of swelling agent, dosages of fluorescent substance, swelling time and swelling temperature. Considering that the structure of microspheres can influence the swelling properties, the paper mainly focuses on the effect of molecular weight and surface carboxyl group content of polystyrene microspheres on swelling properties. When the molecular weight of microspheres is 75276 g mol-1, the density of carboxyl group on their surface is 6.94×10-4 mol g-1, and the doping amount of europium complex reaches the maximum of 24.9 mg g-1 with the strongest fluorescence intensity. Meanwhile, the as-prepared fluorescent microspheres have high monodispersity, uniform particles size and high thermal stability (the decomposition temperature is 385 oC), which sets up the good foundation for biomolecule detection. So, this work provides a significant experience for the preparation of fluorescent microspheres.

scholarly journals Treatment of Alhagi Residues with Tartaric Acid for the Removal of Zn(II) Ions from Aqueous Solution

2008 ◽  
Vol 26 (9) ◽  
pp. 661-678 ◽  
Author(s):  
A. Hashem ◽  
A. Abdel-Lateff ◽  
S. Farag ◽  
D.M. Hussein
Keyword(s):  
Aqueous Solution ◽  
Tartaric Acid ◽  
Ph Value ◽  
Carboxyl Group ◽  
Factors Influencing ◽  
Group Content ◽  
Equilibrium Data ◽  
Carboxyl Group Content ◽  
Ft Ir ◽  
Temperature Factors

Alhagi cellulose tartrate (ACT) with a high carboxyl group content was prepared by treatment of Alhagi residues (AR) with tartaric acid (TA) at high temperature. Factors influencing the reaction were investigated, viz. tartaric acid concentration, dehydration temperature, particle size and dehydration time. The prepared Alhagi cellulose tartrate samples were characterized using FT-IR spectroscopy and by estimation of the carboxyl group content. The esterified samples were utilized for the adsorptive removal of Zn(II) ions from aqueous solution with all the factors influencing the process being studied. These factors were the pH value of the adsorbate solution, the adsorbent concentration, agitation time and temperature. The Langmuir and Freundlich models were applied to the data obtained from the adsorption studies. It was demonstrated that the Alhagi cellulose tartrate samples could be used effectively for the adsorption of Zn(II) ions from aqueous solutions. The thermodynamics constants of the adsorption process, viz. ΔH0, ΔS0 and ΔG0, were evaluated. The results showed that the adsorption of Zn(II) ions onto ACT was exothermic and spontaneous. The adsorption data followed second-order kinetics, with the equilibrium data being only satisfactorily described by the Langmuir isotherm.

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