Preparation And Characterization Of The Natural Oil Sorbents From Corn Straw

Corn straw is used in various aspects， because it represents an abundant，inexpensive， and readily available source of reusable cellulosic biomass. In thispaper， an investigation about the acetylation of cellulose fibers extracted by acidifiedsodium chlorite and sodium hydroxide from corn straw fibers was undertaken toexamine its potential for use as sorbents in oil spill cleanup. Characterization ofacetylated and untreated straw fibers was performed by FT-IR， SEM， XRD， BETand contact angle.The extent of acetylation was measured by weight percent gain (WPG)， whichincreased with the extent of reaction time and temperature. According to WPG and oilsorption capacity of the acetylated cellulose fibers for pure oil and oil slick， theoptimum acetylated condition for cellulose fibers is at120℃for7h. The oil sorptioncapacity of the acetylated cellulose fibers at the optimum prepared condition was42.53，52.65and67.54for vacuum pump oil，diesel oil and crude oil，respectively.The oil sorption capacity of the acetylated cellulose fibers for oil slick was larger thanthat for pure oil. And if the oil amounts were considerably below its oil sorptioncapacity， the acetylated cellulose fibers could remove oil without settlement. Asshown by the adsorption kinetic experiments， more than90%of the diesel oil wasabsorbed by the acetylated cellulose fibers within the first5min and the adsorptionkinetic was consistent with the simulated-second-order model.Characterization of the cellulose fibers was performed by FT-IR， SEM， XRDand contact angle analysis. Contact angle analysis indicated that the acetylatedcellulose fibers had a better hydrophobic–oleophilic characteristic than untreated one.FT-IR spectrum demonstrated that，the cellulose fibers were extracted from the strawfibers by pretreatment and the hydroxyl groups of cellulose fibers were substituted byacetyl groups. Straw fibers morphology and microstructure analyzed by SEMindicated that the external diameter， the roughness and the fold of fibers surfaceincreased sharply. In addition， acetylation also increased the fraction void on thefibers surface demonstrated by XRD.