| As the global population expands and industrialization progresses at an unprecedented pace,energy consumption has surged,with fossil fuels such as oil,natural gas,and coal remaining the primary sources.During the extraction and transportation of crude oil,leaks and pollution incidents are frequent occurrences.Statistics indicate that approximately 7.3 million barrels of crude oil enter the natural environment annually through various channels,resulting in oil pollution.Harmful substances in oil,such as aromatic hydrocarbons,can cause water,soil,and air pollution following oil and gas volatilization.The primary methods for treating oil pollution include adsorption,combustion,and biodegradation.Of these methods,adsorption is the simplest,fastest,and most efficient method with low cost and broad applicability.Among adsorbent materials,aerogel materials possess characteristics such as low density,high adsorption capacity,and high porosity,making them promising for practical applications.The production of aerogel adsorbents from biomass waste not only effectively addresses oil pollution issues but also transforms biomass waste into a valuable resource for reuse.The resulting aerogel materials exhibit excellent environmental compatibility and do not cause secondary pollution.Therefore,biomass aerogel adsorbent materials hold significant research value.This project employed a bottom-up approach to synthesize a series of aerogel adsorbent materials from various biomass sources(bagasse,corn stalks,sodium alginate,green leaf pectin).These materials were characterized using a range of techniques(SEM,FTIR,XRD,XPS,BET),and their oil absorption performance and mechanisms were investigated in detail.Nanocellulose(CNF)extracted from bagasse was combined with sodium alginate(AS),and calcium ion crosslinking and freeze-drying were employed,followed by surface hydrophobic modification via chemical vapor deposition to produce a hydrophobic cellulose/sodium alginate aerogel.The combined action of the two raw materials results in a mixed aerogel with excellent compression resilience.Due to the aerogel’s low density(7.55 mg/cm~3)and large specific surface area(39.15 m~2/g),its adsorption capacity for optimized sample reached 89～126 g/g.Additionally,the surface hydrophobicity and oleophilicity of the aerogel,resulting from chemical vapor deposition,yielded a contact angle with water of 135°,indicating its potential for broad applicability in the field of oil absorption.Secondly,CNF extracted from corn stalks was compounded with green leaf pectin(PML)to synthesize a green leaf aerogel based on corn stalks using various freezing methods and surface hydrophobic modification.Different freezing methods resulted in distinct ice crystal growth modes,leading to variations in pore structure and impacting the adsorption performance of the aerogel.Random freezing in a refrigerator produced disordered stacked pores and layers,while unidirectional freezing generates a unidirectional capillary structure.Experimental results demonstrated that when the CNF/PML mass ratio was 9/1,the material exhibited optimal oil absorption performance.The oil absorption performance of the sample frozen in a refrigerator was superior to that of the unidirectionally frozen sample,at 130.1 and 97.5 g/g respectively.Additionally,this aerogel displayed excellent hydrophobic performance(contact angle with water of 132°),high adsorption capacity for various oils and organic solvents(81.8～160.8 g/g),and can undergo cyclic adsorption more than 15 times.All in all,a series of bio-based aerogel absorbents have been fabricated via different methods to clarify the effect,study the physicochemical character and test the absorption capacity.The applicability of bio-based aerogels to oil-water separation has been verified,that could provide a new course in oil-spill treatment,bio-waste reuse and recycle. |
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