Synthesis And Application Of Macro-/Mesoporous Carbon Materials With Hydrophobicity

Frequent oil spill accidents can lead not only to serious environmental pollution,but also a great loss of energy and economic.Facing these great challenges,scientists have always devoted themselves to developing new technologies and new materials for oil-water separation.The fabrication of special wettable oil sorbent materials is one of the most promising methods for cleaning oil from contaminated areas.The widespread use of porous carbons results from their remarkable properties,such as easy handling and low cost of manufacture,good thermal stability,chemical inertness,radiation resistance,recyclability without toxic and secondary pollution.It is worth noting that the incorporation of mesopores in macroporous carbon materials may be somewhat more interesting and useful for mass transport in the field of water purification.Macro-/mesoporous carbon materials are well-suited to elimination of organic contaminants,particularly important for the removal of large hydrophobic oil molecules in viscous systems.In this dissertation,we emphasize the template synthetic procedure for macroporous carbon materials by inverse replicas of the three-dimensionally(3D)network structure.We mainly focus on the research of macroporous carbon materials,including the incorporation of ordered mesopores in macroporous materials by evaporation-induced assembly method,and the building hydrophobic micro/nano-scale architectures.In particularly,we pay attention on the shape and morphology,pore structure,skeleton structure,and surface wettability of macro-/mesoporous carbon materials.Futhermore,we highlight the hydrophobic macro-/mesoporous carbon materials that can be used as oil sorbents.The absorption capacity,sorption behavior,reusability and sorption mechanism of samples are presented and discussed.First,a dual-templating approach is demonstrated to prepare the 3D ordered macro-/mesoporous carbon.Polystyrene colloidal crystal is used as 3D ordered macroporous skeleton,triblock copolymer as mesoporous structure-directing agent,and soluble resol as carbon source.On the basis of periodic 3D arrays,the sample exhibited the biomimetic structural color,submicro-scale macropores(221 nm),nano-scale mesopores(12 nm),high specific surface area(753 m2/g)and high pore volume(0.58 cm~3/g).Then,we demonstrate a strategy to fabricate reticulated macro-/mesoporous carbon with designed shapes from commercial melamine sponge template.Benefited from a simple evaporation-induced self-assembly and coating process,the nano-scale ordered mesopores can be successfully introduced into the reticulated macroporous system.The as-made carbon exhibits interconnected,aperiodic macropores(75~112 mm),irregular wrinkles distributed on the surface of blocked macropores,well-ordered hexagonal arrays of mesopores(6.3~4.7 nm),high specific surface area(686~959 m2/g),high pore volume(0.51~0.54 cm~3/g).Furthermore,sample can resist high temperature under 500 oC,suggesting superior thermostability and fire-resistant property.As inverse replicates of the 3D interconnected network structure by the dual-templating method,the obtained macro-/mesoporous carbon materials exhibited micro/nano-scale porous architecture by the skeletal macroprous walls surrounded regular mesopores.The results suggest that the as-fabricated carbon materials exhibit excellent hydrophobicity(water contact angle,118.4~130.0°).The samples can selectively collect oil from water surface,showing the sorption capacity of 0.9~2.1 g/g for organic solvents and oils.Sorption mechanism of hydrophobic macro-/mesoporous carbon materials can be ascribed to the combination of multimolecular layer absorption on the macropores,accumulation of oil macromolecule on the macropores,and capillary condensation on the mesopores.