Production of cellulose aerogels from coir fibers via an alkali–urea method for sorption applications
- 5 Downloads
Biodegradable cellulose aerogels have been successfully prepared from coir fibers using a sulfur-free method and NaOH–urea system. Sulfur was avoided during pretreatment because it is environmentally harmful. Interestingly, these pretreatments had a strong effect on the physical properties of the aerogels produced. Good physical properties of the cellulose aerogels were obtained when the Kappa number, i.e., the lignin content, in the pulp was lower than 14.8. NaOH–urea played an important role in transforming cellulose I to cellulose II and crosslinked cellulose to form an aerogel structure. The aerogel had a macroporous structure, ultralight density, high porosity, good durability, and thermal stability. The aerogel was capable of absorbing 22 and 18 times its dry weight in water and oil, respectively. The material also had a high capacity for methylene blue dye adsorption of up to 62 g/g, which was one hundred times higher than that of adsorbents synthesized from the other natural matters. Therefore, the prepared aerogels have potential for various sorption applications.
KeywordsNaOH–urea system Absorbent Adsorbent Coir fibers Cellulose aerogel
This work was supported by the Ministry of Research, Technology and Higher Education, Indonesia through a PMDSU Research Grant (Contract Numbers 15304/IT2.11/HK.00.02/2016, 77186/IT2.VII/HK.00.02/2017, and 798/PKS/ITS/2018). One of the authors (M.F.) would like to thank the Ministry of Research, Technology and Higher Education, Indonesia, for a doctoral scholarship through PMDSU. We thank Ms. Tiara Nur Pratiwi and Mr. Muhammad Abid Hidayatullah for their assistance with the experiments. We also thank Ms. Annie Mufyda Rahmatika for the TGA analysis.
- Baldanza VAR, Souza FG, Filho ST, Franco HA, Oliveira GE, Caetano RMJ, Hernandez JAR, Ferreira Leite SG, Furtado Sousa AM, Nazareth Silva AL (2018) Controlled-release fertilizer based on poly(butylene succinate)/urea/clay and its effect on lettuce growth. J Appl Polym Sci 135:51–60. https://doi.org/10.1002/app.46858 CrossRefGoogle Scholar
- Foster JJ, Forge C (1993) Kappa number calibration standard 1–7. Westvaco Corporation, New York, US Patent 5194388Google Scholar
- Han Y, Zhang X, Wu X, Lu C (2015) Flame retardant, heat insulating cellulose aerogels from waste cotton fabrics by in situ formation of magnesium hydroxide nanoparticles in cellulose gel nanostructures. ACS Sustain Chem Eng 3:1853–1859. https://doi.org/10.1021/acssuschemeng.5b00438 CrossRefGoogle Scholar
- Ioelovich M, Leykin A, Figovsky O (2010) Study of cellulose paracrystallinity. BioResources 5:1393–1407Google Scholar
- Kathirselvam M, Kumaravel A, Arthanarieswaran VP, Saravanakumar SS (2019) Isolation and characterization of cellulose fi bers from Thespesia populnea barks: a study on physicochemical and structural properties. Int J Biol Macromol 129:396–406. https://doi.org/10.1016/j.ijbiomac.2019.02.044 CrossRefGoogle Scholar
- Laurichesse S, Avérous L (2014) Chemical modification of lignins: towards biobased polymers. Prog Polym Sci 39:1266–1290. https://doi.org/10.1016/j.progpolymsci.2013.11.004 CrossRefGoogle Scholar
- Olsson RT, Samir MASA, Salazar-Alvarez G, Belova L, Strom V, Berglund LA, Ikkala O, Nogues J, Gedde UW (2010) Making flexible magnetic aerogels and stiff magnetic nanopaper using cellulose nanofibrils as templates. Nat Nanotechnol 5:584–588. https://doi.org/10.1038/nnano.2010.155 CrossRefGoogle Scholar
- Pääkkö M, Vapaavuori J, Silvennoinen R, Kosonen H, Ankerfors M, Lindström T, Berglund LA, Ikkala O (2008) Long and entangled native cellulose I nanofibers allow flexible aerogels and hierarchically porous templates for functionalities. Soft Matter 4:2492–2499. https://doi.org/10.1039/b810371b CrossRefGoogle Scholar
- Salas C, Ago M, Lucia LA, Rojas OJ (2014) Synthesis of soy protein–lignin nanofibers by solution electrospinning. React Funct Polym 85:221–227. https://doi.org/10.1016/j.reactfunctpolym.2014.09.022 CrossRefGoogle Scholar
- Sarko A, Nishimura H, Okano T (1987) Crystalline alkali–cellulose complexes as intermediates during mercerization. In: Atalla RH (ed) The structure of cellulose. American Chemical Society, Washington, DC, pp 169–177Google Scholar
- Wang S, Peng X, Zhong L, Tan J, Jing S, Cao X, Chen W, Liu C, Sun R (2015) An ultralight, elastic, cost-effective, and highly recyclable superabsorbent from microfibrillated cellulose fibers for oil spillage cleanup. J Mater Chem A 3:8772–8781. https://doi.org/10.1039/C4TA07057G CrossRefGoogle Scholar