Preparation of oil sorbents by solvent-free grafting of cellulose cotton fibers
Natural cellulose-based fibers, such as cotton, have been investigated as oil sorbent to remediate and recover oil spills. The unmodified fibers are hydrophilic and have a high capacity to absorb water. To circumvent this drawback, the hydrophobicity of fibers is usually enhanced by chemical modification using solution-based processes that produce significant amounts of chemical waste. In the present study, gas–solid solvent-free silylation reaction was used to graft alkyl groups on cotton fibers. The modified cotton fibers were characterized by IR-spectroscopy, TGA analysis and SEM–EDS. The degree of substitution varied between 0.1 and 0.3 per glucose residue. The ability of the fibers to remove oil from the surface of simulated sea-water was investigated and all the modified fibers have adsorption capacity at least five times that of unmodified cotton. To optimize the adsorption capacity, factors that affect oil adsorption were investigated, namely the effect of fiber–oil contact time, temperature, and length of the grafted alkyl chains. Cotton fibers grafted with dialkyl substituted silyl ethers, through solvent-free silylation reaction, were found to have the best adsorption capacity of ~ 18 g oil/g of modified cotton with a fiber–oil contact time of 10 min at 25 °C.
KeywordsGas–solid silyl reaction Modified cellulose Hydrophobicity Oil pollution remediation Cotton
The authors thank the Department of Chemistry at the United Arab Emirates University and the Department of Biology, Chemistry and Environmental Sciences at the American University of Sharjah for their technical support, and Mr. Essa Lwisa for providing help to measure the contact angles of the samples. M. A. thanks Gulf Ecosystems Research Center at the American University of Sharjah for the financial support (Grant No. GER-14-04).
- Allen A (1988) In-situ burning: a new technique for oil spill response. Spiltec, WoodinvilleGoogle Scholar
- Board OS (2005) Oil spill dispersants: efficacy and effects. National Academies Press, WashingtonGoogle Scholar
- Brook M, Dawoud M (2005) Coastal water resources management in the United Arab Emirates. In: Integrated coastal zone management in the United Arab Emirates pp 1–12Google Scholar
- Choi HM (1996) Needlepunched cotton nonwovens and other natural fibers as oil cleanup sorbents. J Environ Sci Health Part A 31:1441–1457Google Scholar
- Isehunwa S, Udeagbara SG, Akpabio J (2011) Effect of temperature and contamination on the surface tension of niger delta crude oils. Aust J Basic Appl Sci 5:610–616Google Scholar
- Israelachvili J (2011) Intermolecular and surface forces, 3rd edn. Academic Press, CambridgeGoogle Scholar
- Nomack M (2010) Oil spill control technologies. Retrieved from http://editors.eol.org/eoearth/wiki/spill_response_(Oil_spill_control_technologies)
- Plueddemann EP (2013) Silane coupling agents. Springer, New YorkGoogle Scholar
- Smith AL (1974) Analysis of silicones. Wiley, HobokenGoogle Scholar
- Tewari N, Verma V, Rai J (2006) Comparative evaluation of natural adsorbent for pollutants removal from distillery spent wash. J Sci Ind Res 65:935Google Scholar