shaghayegh rezanezhad; Hossein Resalati; Seyed Majid Zabihzadeh
Abstract
Biodegradable magnetic nanocomposites of cellulose have been widely used in adsorption of heavy metals from water. In this research, nano magnetic papers were produced by commercial craft long fiber (NMP), magnetic fibers with 1% gluconic acid (NMP / GA 1%), nanocrystalline cellulose (MNCC) as well as ...
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Biodegradable magnetic nanocomposites of cellulose have been widely used in adsorption of heavy metals from water. In this research, nano magnetic papers were produced by commercial craft long fiber (NMP), magnetic fibers with 1% gluconic acid (NMP / GA 1%), nanocrystalline cellulose (MNCC) as well as carboxymethyl cellulose (MCMC), and the adsorbents were used to remove heavy metals of lead (Pb) and nickel (Ni). The nanocomposites were evaluated by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and sample vibration magnetometer (VSM). X-ray diffraction patterns showed that magnetic fibers and composites were successfully produced and the nano magnetite peaks were observed in all samples. Examination of nano magnetite and cellulose nanocrystals showed that most of the particles were in the range of 1 - 19 and 1 - 65 nm, respectively. The highest magnetic saturation was related to the nanocrystalline cellulose magnetic composite. Adsorption samples were examined by a microwave plasma atomic emission spectrometer. The results of lead and nickel adsorption test showed that the NMP / GA 1%, MCMC and control sample adsorbents had highest and lowest amount of lead and nickel adsorption, respectively. Lead metal also has a higher adsorption than nickel with all the adsorbents.
Zahra Gholami; Mohammad Azadfallah; soheila izadyar; Mehdi Roohani
Abstract
In this research, deinked pulp (DIP) was modified with carboxymethyl cellulose (CMC) in order to introduce more charged groups on the surfaces of fibers which leads to improve strength properties. Modification of the pulp was conducted at mild reaction temperature conditions of 85, 95°C and 120°C ...
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In this research, deinked pulp (DIP) was modified with carboxymethyl cellulose (CMC) in order to introduce more charged groups on the surfaces of fibers which leads to improve strength properties. Modification of the pulp was conducted at mild reaction temperature conditions of 85, 95°C and 120°C at 60 and 90 minutes, and under sever conditions of 120°C for 120 minutes in the presence of calcium chloride as electrolyte. The drainage time, water retention value (WRV), tensile strength, burst strength, brightness and opacity of CMC-modified pulps were measured and compared with corresponding values of blank (untreated) pulp and CMC-treated pulps as conventional treatment. The results indicated that tensile strength and burst strength of CMC-modified pulps were improved in comparison with unmodified pulps. The behavior of pulps was different in terms of optimum reaction condition. However, no significant changes were observed for optical properties of CMC-modified pulps. Water retention value of CMC-modified pulps decreased unexpectedly in some conditions.
Chemical conversion
Milad Poladi; Seyed Hassan Sharifi; Seyed Majid Zabihzadeh; Mostafa Nikkhah Dafchahi
Abstract
Cellulose is the most abundant bio-polymer and also has many potential and applications, Therefore, in order to convert it to solvable cellulose in many commercial solvents, it is necessary to modify the cellulose structure with a variety of methods of derivation. Cellulose derivatives have an increasing ...
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Cellulose is the most abundant bio-polymer and also has many potential and applications, Therefore, in order to convert it to solvable cellulose in many commercial solvents, it is necessary to modify the cellulose structure with a variety of methods of derivation. Cellulose derivatives have an increasing share in the cellulosic products marketing and it is used in various industries such as sanitary, pharmaceutical, food and industrial., Carboxymethyl cellulose is one of the most important commercial cellulose ether derivatives. The purpose of this study was to investigate the conversion of alpha-cellulose derived from the Deltoides pine species into a useful and more valuable product that called Carboxymethyl cellulose. In order to optimize and investigate the interaction of different process variables, response surface methodology (RSM) was used. For modeling the process, important operational parameters such as concentration of NaOH, ratio of Monochloroacetic acid to cellulose, temperature and the time of etherification as independent variables and the degree of substitution of the samples were considered as the desirable response. Analysis of variance and response level were used to create a function between variables and responses, and optimal conversion conditions were determined. The results showed that the best value presented in the optimal condition proposed by software for the degree of substitution was 31 percent for concentration of etherification, 1.09 for the ratio of Monochloroacetic acid to cellulose, 60 °C for the etherification temperature and 157 minutes for the etherification time.
Chemical conversion
Hamedeh Kiani; Hosein Resalati; Seyed Hassan Sharifi
Abstract
Carboxymethyl cellulose (CMC) is one of the important cellulose derivatives in industries, which is widely used as anti-caking agent, emulsifier, stabilizer, dispersing agent, thickener, and gelling agent. The main raw material of cellulose derivative is cellulose from wood and cotton linter. In this ...
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Carboxymethyl cellulose (CMC) is one of the important cellulose derivatives in industries, which is widely used as anti-caking agent, emulsifier, stabilizer, dispersing agent, thickener, and gelling agent. The main raw material of cellulose derivative is cellulose from wood and cotton linter. In this study, the cotton linter alpha-cellulose was used for producing CMC. Acidified sodium hydroxide process was applied to extract the cellulose from linter alpha-cellulose. Carboxymethyl cellulose was then prepared from cellulose. The optimization of reaction conditions was studied by using response surface methodology (RSM). The design experiment is Box-Behnken design consists of 3 factors (reaction time, % NaOH in mercerization process and mass ratio of monochloroacetic acid to cellulose in etherification process) with 3 levels. Based on it, the optimum values of independent variables are the reaction time of 54.23 min, NaOH concentration of 41.25 % and mass ratio of MCA to cellulose of 1.44 which the CMC had the DS of 0.656, the viscosity of 6634.76 cP. Fourier Transform Infrared spectra (FTIR) were used to characterize the product and starting Cotton Linter Alpha-cellulose.
