Cellulose aerogel composites as oil sorbents and their regeneration

Abstract

Background With every oil tanker comes the risk of an accident and oil spill. Sorbents are the most suitable means to remove oil spills. Aerogels as sorbents have high porosity and can be made from cellulose from paper waste. The literature does not distinguish between paper and cardboard as sources of cellulose aerogels and little is known about composites of cellulose aerogels consisting of cellulose fibres and chemically untreated, unprocessed fibres or particles of straw, wool, macroalgae or cellulose acetate from cigarette butts. In this study, the sorption properties for marine diesel oil and biodiesel of such aerogels and their regenerative capacity with bioethanol were investigated. Methods Cellulose aerogels were prepared from office paper and cardboard waste without and with chemically untreated algae, straw, wool and cellulose acetate as a composite by freeze drying. All samples were hydrophobised with methylsilane. The density to calculate the porosity and the contact angle were determined. Then the sorption capacity was determined over five cycles of sorption of oil and regeneration with bioethanol. Results The average contact angle of all samples was 125°, indicating hydrophobicity. Paper-based aerogels were found to consistently have higher sorption capacities for biodiesel, marine diesel oil and bioethanol than cardboard-based aerogels. In particular, the wool/cellulose aerogel composite was found to have better sorption capacity for biodiesel, marine diesel oil and bioethanol than all other samples. The cellulose acetate/cellulose aerogel composite showed significantly higher sorption capacities than the paper and cardboard control samples (highest value is 32.25 g g−1) only when first used as a sorbent for biodiesel, but with a rapid decrease in the following cycles.

Microbial applications for sustainable space exploration beyond low Earth orbit

“…Aerogels, first created by Kistler in 1931, are human-made, low-density solid materials with an interconnected porous network composed of 99.8% air, with the most common type being silica-based 281 . Photosynthetic organisms that can produce silica, primarily algae diatoms ( e.g., Phaeodactylum tricornutum ), are of interest for the generation of silica-based aerogels and have recently been incorporated into cellulose aerogel composites 282 , 283 . Aerogels are useful materials for space applications due to their low thermal conductivity, light weight, and high porosity 284 – 286 .…”

Natural polysaccharide-based aerogels and their applications in oil–water separations: a review

“…Better microstructure and wetting properties help improve the oil adsorption capacity, and aerogels with high porosity generally have higher oil absorption capacity because they provide more internal free volume to absorb the oil; this may depend on the ingredients and additives used. Paulauskiene et al 154 prepared regenerated cellulose aerogel with office paper and cardboard, respectively. The results showed that the porosity and wettability were within the same range but there were significant differences in the density and adsorption capacity between the two types of the cellulose aerogel.…”

Bacterial Cellulose-Based Polymer Nanocomposites: A Review

“…Nanocellulose-based materials can also be used to treat wastewater contaminated with hazardous organic pollutants, including dyes, pharmaceutical compounds, and petroleum products [ 292 , 316 , 317 , 318 , 319 , 320 ]. For example, Wang et al reported a new superabsorbent aerogel based on BC and graphene oxide, which showed excellent absorption property of organic liquids [ 316 ].…”

“…For example, Wang et al reported a new superabsorbent aerogel based on BC and graphene oxide, which showed excellent absorption property of organic liquids [ 316 ]. Cellulose composite aerogels can be used for oil sorption [ 318 , 319 ]. The development and synthesis of new materials is vital to the removal of new contaminants, such as pharmaceuticals, from polluted water.…”