Preparation And Oil Absorption Performance Of Bio-Based Carbonaceous Aerogel

With the development of the global economy,the demand for oil in various countries has increased sharply.The oil transportation is mainly through maritime transportation.The accident of oil tanker suffering from shipwreck damage caused by oil tanker is also frequent.Oil pollution seriously affects the ecological environment and human health.Therefore,dealing with crude oil pollution is extremely urgent.At present,there are mainly physical methods,chemical methods and biological methods for dealing with crude oil pollution.The above methods have certain limitations in the process of use.The physical methods generally use physical methods when the wind speed on the sea surface or the river surface is not high,and the sea surface is not large.The advantage is that the operation is simple,and the disadvantage is that when the sea surface is large,the water flow When the speed is fast,the mechanical requirements are relatively high and the decontamination effect is not ideal,and there are safety hazards in the work process.In the harsh climatic conditions,or in deep water conditions,when the boom and skimmer cannot function,the chemical method is very advantageous when dealing with crude oil.The chemical method mainly involves adding dispersant to the sewage surface.The other is to choose to burn the oil on the spot.The advantage is that it can be quickly decontaminated and the operation is simple and quick.The disadvantage is that the cost of the dispersant is too high,and it is not economical.Although the cost of incineration on the spot is small,it can be quickly decontaminated,but the environmental pollution is relatively large,and secondary pollution will occur.Biological methods rarely produce pollution when dealing with slop oil,do not destroy the ecosystem of the waters,and are environmentally friendly decontamination methods,but the biological decontamination time period is longer and the decontamination speed is slower.The above decontamination methods are subject to various conditions and are not versatile,fast,efficient,sustainable,and recyclable when handling oil.In order to improve these deficiencies in traditional degreasing methods,we intend to develop an oil-absorbing and decontaminating material that is versatile,efficient,inexpensive,sustainable and recyclable.Because carbon aerogel has large specific surface area,high porosity,low density,uninterrupted three-dimensional network structure and good mechanical properties,it is often used as an adsorbent for wastewater treatment?For example,the separation of oil and water,the removal of heavy metal ions from water,and so on?.In addition,biomass materials are low in cost and rich in carbon sources.They are the most economical,environmentally friendly and sustainable raw materials in the preparation of carbonaceous aerogels.Therefore,we use biomass as raw material to prepare biomass carbonaceous aerogels.Modification to prepare a lipophilic/hydrophobic carbonaceous aerogel material that allows for quick and efficient processing of oil stains.Based on the above research objectives and concepts,we conducted a series of experimental studies,and the results obtained mainly include the following three aspects:?1?In the preparation experiments of bio-based carbonaceous aerogels,we found that soft plant tissues produced carbon nanoparticles mainly by hydrothermal carbonization,and their macroscopic and microscopic structures changed significantly;fixed structure of hard plant tissues It can retain the external shape and macroscopic and microscopic structural features in a wide range,and produce significant structural changes at the nanometer scale to form a micro/mesoporous network structure.Therefore,we have selected hard plants as carbon sources to prepare carbonaceous gases.gel.?2?Using a simple one-step low-temperature hydrothermal carbonization method with biomass lettuce as a carbon source,a low-cost,environmentally friendly carbonaceous aerogel?named CA?was prepared under mild experimental conditions.The carbonaceous aerogel made from lettuce was modified to prepare a lipophilic/hydrophobic carbonaceous aerogel?named as PDMS-CA?,which was then applied to oil absorption experiments.The physical and chemical properties of the prepared PDMS-CA materials were analyzed.After the modification of CAMS,the water contact angle increased sharply from 0°to 144.2°,indicating that PDMS-CA has hydrophobic/lipophilic properties.We can use SEM electron microscopy.It can be seen from SEM images that the PDMS-CA skeleton has a rough surface and many small peaks,which is similar with the surface structure of the lotus leaf.The pore properties of the prepared PDMS-CA were studied by N₂ adsorption-desorption isotherm combined with artificial pore volume measurement.It indicates that the BET surface area and pore volume of PDMS-CA are 16.02 m²g^-1and 4.13 cm³g^-1,respectively.The smaller surface area and larger pore volume indicate that PDMS-CA has macroscopic macroporous structure;The adsorption capacity of PDMS-CA for crude oil,diesel,n-hexane,peanut oil and engine oil were 10.6 g·g^-1,8.4 g·g^-1,3.3 g·g^-1,9.7 g·g^-1and11.4 g·g^-1respectively.The successful modification of CA by PDMS was verified by IR and XPS.The power supply voltage,oil viscosity and oil absorption were discussed.The effect of nozzle height on the oil absorption performance of PDMS-CA materials.?3?Compared with lettuce,the biomass loofah has higher fiber content and has certain pores.In addition,the corrosion resistance of loofah is also due to lettuce,and the loofah contained therein also has a certain adsorption effect.Therefore,we prepared a biomass carbonaceous aerogel?named as CAAS?using biomass loofah as a carbon source,and modified its surface to finally obtain a lipophilic/hydrophobic carbonaceous aerogel material?named as PDMS-CAAS?,and the physical and chemical properties of PDMS-CAAS and the oil absorption mechanism of PDMS-CAAS-based oil absorption device were also studied.