Preparation Of Functionalized Self-Heating Sponges And Their Application In Oil Spill Clean-Up

Serious marine oil spills frequently occur worldwide due to the rapid development of the petrochemical industry,causing not only severely wasted resources but also incalculable damage to the ecological habitat and human health.Developing novel absorbent materials with both rapid absorption speed and efficient recovery of viscous crude oils presents an enticing prospect for crude cleanup and utilization.Various technologies such as chemical dispersion,biodegradation,and physical absorption have been applied to deal with crude oil spills.Among these methods,physical absorption is regarded as the most promising strategy due to its simple and green route without the introduction of secondary pollution.However,unlike other light crude oils,heavy crude oil has extremely high viscosity.The problem of how to reduce the viscosity of crude oil and quickly absorb and recover it remains a persistent and challenging issue.Therefore,advanced absorbents must meet the requirements of superior hydrophobic/oleophilic behavior,favorable adsorption efficiency,high photothermal or Joule heating performance,and able to be recycled multiple times to handle frequent crude oil spills.This project aims to address the issue of oil spill cleanup through physical absorption.We have used a simple impregnation coating and wet papermaking method to prepare a three-dimensional porous material that can reduce the viscosity of crude oil and adsorb it by physical and chemical methods.The main work is as follows:1.Proposing a strategy that utilizes solar-assisted chemical emulsifiers to synergistically reduce the viscosity of crude oil.Using commercial polyurethane sponge as the framework,we uniformly coated polydopamine and silica nanofluids（Si O₂nfs）on its surface through a simple dipping method,obtaining a composite sponge of silica fluid/polyurethane（PSi NFs@PU）.The FT-IR,TG,SEM,XPS and other tests characterized the successful deposition of polydopamine and Si O₂nfs on the sponge surface.Materials Studio molecular dynamics simulations show that silica nanofluid as a chemical emulsifier has a powerful emulsifying viscosity-reducing effect on crude oil,which has a synergistic effect with the photothermal physical viscosity reduction of the polydopamine layer.Compared with commercial sponge,the photothermal conversion performance,adsorption rate and recovery rate of the modified sponge were verified through contrast experiments,demonstrating the synergistic advantage of the photothermal properties of Si O₂nfs and polydopamine layer,compared to a commercial polyurethane sponge,the modified sponge exhibited a 10%increase in absorption capacity,the oil absorption speed increased by 99.6%,from 10^-3m L cm^-3s^-1to 10^-1m L cm^-3s^-1,and its crude oil recovery rate remained stable at over 90%after 8cycles.2.Inspired by bird’s nests,proposing a polymer"welding"strategy to prepare three-dimensional porous materials.Using carbon fiber and polyphenylene sulfide（PPS）as raw materials to form a three-dimensional welded porous structure（PPS/CF）by using PPS as a"binder"to connect the discontinuous carbon fibers together.The successful preparation of the three-dimensional porous adsorbent material was characterized by tests such as SEM,Raman spectroscopy,XPS,and FT-IR.Tests such as TG,contact angle,and cyclic compression showed that PPS/CF has good thermal stability,superhydrophobicity,and oil affinity as well as mechanical properties,with a water contact angle as high as 152°.In addition,the continuous conductive network endows the oil absorbent mat with high photothermal and Joule heating effects.When the light intensity is 3.0 k W m^-2,the heating rate increases to 9.4°C s^-1,and the surface maximum equilibrium temperature reaches 238°C when a voltage of 5 V is applied at both ends.The maximum heating rate is 57.3°C s^-1,and the maximum absorption rate is increased,reaching 5.2 m L cm^-3s^-1.Finally,the flame retardancy of PPS/CF was evaluated by LOI and combustion tests.The LOI value of the adsorbent material was as high as 45%,and it could suppress the combustion of crude oil in case of fire,thus reducing environmental pollution.