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A modified freezing-thawing cyclic (FTC) process was applied to dissolve the chitin in NaOH/urea solution. A transparent homogeneous solution was obtained. It was utilized directly for preparing the superabsorbent polymers (SAPs) by grafting copolymerization under static solution conditions without nitrogen protection. The acrylic acid was used conveniently without prior neutralization. The final products existed as hydrogels without excess reagent emissions. The adsorption capacity and yield of SAP that was prepared in the optimum conditions was 2833 g/g and 81.65%, respectively, higher than one-time FTC program prepared with 2527 g/g and 15.44%. Furthermore, it formed a uniform and transparent gel without any residual chitin particles. The regenerated chitin and SAPs were characterized by SEM, FTIR, XRD, and TG. The samples prepared by the new method presented a more amorphous state with good thermal stability, suggesting that this convenient preparation method for a potential industrial application's pathway.
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http://dx.doi.org/10.1016/j.carbpol.2013.01.010 | DOI Listing |
Biophys J
August 2025
UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States; UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States. Electronic address:
Associations between cellulose are important both in biofuel production and in the use of cellulose for biomaterials. Cellulose nanofibers (CNFs) are sustainable, strong, light-weight alternatives to traditional materials in manufacturing, but are challenging to obtain due to irreversible aggregation in solution during preparative fibrillation. Therefore, it is imperative to understand the underlying factors driving aggregation with a view to designing solvents that can effectively compete with inter-fiber interactions, hence reducing aggregation.
View Article and Find Full Text PDFCells
May 2025
Department of Oral Medicine, College of Dental Medicine, Rangsit University, 52/345 Phahonyothin Rd., Mueang Pathum Thani District, Pathum Thani 12000, Thailand.
Developing scaffolds with a three-dimensional porous structure and adequate mechanical properties remains a key challenge in tissue engineering of bone. These scaffolds must be biocompatible and biodegradable to effectively support osteoblastic cell attachment, metabolic activity, and differentiation. This study successfully fabricated a chitosan-bacterial cellulose (CS-BC) composite scaffold using the solvent casting/particle leaching (SCPL) technique, with NaOH/urea solution and sodium chloride crystals as the porogen.
View Article and Find Full Text PDFJ Environ Manage
June 2025
Główny Instytut Górnictwa (Central Mining Institute), PlacGwarków 1, 40-166, Katowice, Poland. Electronic address:
The organic matter in waste activated sludge (WAS) is extracted via a NaOH/urea aqueous solution combined with ultrasonic treatment to obtain an organic-enriched extractant (S-NaOH/urea). N-doped hierarchical porous carbons (NPCs) are prepared by dissolving cellulose in S-NaOH/urea followed by carbonization and in situ activation. The NaOH/urea aqueous solution serves as a trifunctional medium: organic extractant for WAS, chemical activator, and nitrogen precursor during pyrolysis, significantly enhancing process efficiency while minimizing secondary reagent consumption.
View Article and Find Full Text PDFGels
March 2025
Department of Plant Sciences, North Dakota State University, Fargo, ND 58108, USA.
Utilizing gamma rays as an initiating agent, a simultaneous irradiation method was applied to graft acrylic acid and acrylamide onto corn straw that had been decrystallized using a NaOH/urea solution at a reduced temperature, aiming to fabricate superabsorbent polymer gel (SAPG) capable of absorbing significantly more water. The structural attributes of the corn straw, the decrystallized corn straw, and the SAPG were analyzed via Fourier transform infrared spectroscopy (FTIR), X-ray crystal powder diffraction (XRD), thermogravimetric analysis (TG), and scanning electron microscopy (SEM). To enhance the SAPG's performance, optimization of various parameters was carried out, such as irradiation dose, dose rate, the ratio of monomer to corn straw, the proportion of acrylic acid (AA) to acrylamide (Am), and the degree of neutralization.
View Article and Find Full Text PDFChem Commun (Camb)
February 2025
Jiangsu Collaborative Innovation Centre of Chinese Medicinal Resources Industrialization, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China.
A facile spectrometric determination of lignin in corn straw was constructed through dissolving the lignin-carbohydrate complex in aqueous solution at room temperature, where NaOH/urea was induced to prepare a transparent aqueous solution of carbohydrate-linked lignin for quantification at 298 nm without any interference from the carbohydrate.
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