Construction And Properties Of Functional Emulsion Gel/Aerogel

Colloid chemistry is an important branch of physical chemistry to study properties of colloidal dispersion systems.As an important component of colloidal chemistry,gel materials have been widely applied in flexible electronic equipment,biomedicine,aerospace and other fields.In the research process of gel materials,the development of component variety,structure diversity and function complexity has gradually become the emerging trend.How to realize the function diversity of gel materials,how to realize the controllable adjustment of functional gel materials according to the requirements of applications,and how to combine the unique properties of gel materials with the actual functional applications have become a research hotspot in interdisciplinary fields such as chemistry and materials science.Based on this,the thesis mainly carried out two parts of research:the first part,multiple responsive emulsion gel is constructed based on the functional gel factor,using non covalent interaction and electrostatic interaction.Functional design and regulation of the performance of gel materials are taken to explore the practical feasibility in the application of stimulus responsive cigarette capsule.In the second part,different building blocks and micro structures are selected to build aerogels with electromagnetic interference shielding performance.The influence of material composition and structure on electromagnetic interference shielding performance is explored to further expand the practical application of functional gel materials.The thesis consists of the following four parts:Chapter Ⅰ is the introduction.Starting from the definition and classification of gels,the concept definition of gel materials was introduced.and the development status of functional gel materials was reviewed.The concepts of emulsion gel and aerogel were also introduced,along with their definition,classification,construction strategy and performance suggested in detail.The functional applications of emulsion gel and aerogel were elaborated in detail.Finally,the research content and significance of this thesis are proposed.In Chapter Ⅱ,responsive emulsion gel was designed and synthesized to be applied in cigarette capsule.Considering the practical application,the non covalent interaction among the constituents endows the emulsion gel with temperature.CO2 and stress responsiveness.Spontaneous switch from gel to sol can be realized under the stimulation of rising temperature,smog and squeezing generated during the process of smoking.Therefore the purpose of releasing flavor to enhance fragrance,moisturize the smog and reduce production costs is achieved.We explored the influence of different components and proportions on the properties of emulsion gel and made clear of its responsive mechanism.The emulsion gel can control the release of flavor through the responsive behavior during the smoking.This strategy provides a new method to prepare cigarette capsule with simple synthesis process,green environmental protection and biocompatibility.In Chapter Ⅲ,in order to expand the applications of functional gel materials,we carried out research on aerogel with electromagnetic interference shielding property to solve the increasingly serious electromagnetic pollution problem.From the perspective of building blocks,MXene nanosheets,Cu nanowires and cellulose nanofibers modified with polypyrrole were designed and synthesized to prepare MXene based aerogel through directional freeze-drying method.The effects of component content and proportion on the electromagnetic interference shielding performance of aerogel were explored.We found that the raise of conductive filler would help improve the electromagnetic interference shielding performance of aerogels.This study provides a method to prepare aerogel with lightweight structure and electromagnetic interference shielding,expanding the effect exploration of building blocks on electromagnetic interference shielding performance of aerogels.In Chapter Ⅳ,according to the study in Chapter III,building blocks were modified for better performance,together with the further exploration of the factors that influence electromagnetic interference shielding performance of MXene aerogel from the perspective of construction structure.Different freezing methods and mechanical compression were adopted to explore the influence of aerogel structure on electromagnetic interference shielding performance.We found that anisotropic aerogel has better electromagnetic interference shielding performance while incident electromagnetic wave enters in specific incident direction perpendicular to the pore structure.The shielding of isotropic aerogel to electromagnetic waves is not limited by the incident direction.Aerogel films have outstanding electromagnetic interference shielding performance due to the combination of porous structure of aerogel and the increased conductive path.Along with the thin properties of films,aerogel films show potential in practical application of electromagnetic interference shielding.This work explores the influence of aerogel structure on electromagnetic interference shielding.which may direct the design and synthesis of aerogel in electromagnetic interference shielding applications.