Study On Moisture Control And Purification Of Formaldehyde Of Diatom Shale Interior Wall Coatings

Indoor air humidity and indoor air formaldehyde content greatly affect the comfort and safety of people's living environment.If the humidity is too high or too low,it will cause physical and mental discomfort and affect people's rest efficiency.Formaldehyde is also a toxic substance,and long-term exposure will cause serious harm to the human body.Diatom shale is a material with a unique pore structure.It has the characteristics of light weight,porous,large specific surface area,small pore size,etc.It can be used as an adsorbent material to regulate indoor humidity and adsorb air formaldehyde.Nano-TiO₂ is an n-type semiconductor that can undergo a photocatalytic reaction under light to decompose formaldehyde into CO2 and H2 O.In this project,diatom shale was introduced as a filler and an appropriate amount of nano-TiO₂ was added to develop an environment-friendly interior wall coating with the functions of regulating indoor humidity and adsorbing air formaldehyde.On this basis,the feasibility of introducing nitrogen-doped TiO₂ was analyzed.In this paper,the diatom shale was first analyzed by infrared spectroscopy?FTIR?,thermogravimetric-differential thermal?TG-DTA?,X-ray fluorescence spectroscopy?XRF?,X-ray diffraction?XRD?,and scanning electron microscope?SEM?Analysis,BET specific surface area test,BJH pore size analysis test and other performance characteristics confirmed the composition,micro-morphology and structure of diatom shale.According to the performance characterization results,the diatom shale was subjected to fineness treatment,calcination treatment and acid treatment purification methods,and nano-TiO₂ was prepared by high temperature calcination method.In this paper,the treated raw material is used as a functional filler to design a diatom shale interior wall coating.And conducted performance tests according to relevant standards.The final measured viscosity was 41 s,the hiding power was 185.5g/m2,and the scrub resistance was 408 times,which complied with the Class I interior wall coating standard.In this paper,through the design of humidity control experiments,the absorption and release properties of diatom shale under different purification conditions under different humidity were studied.The results show that the diatom shale with the calcination temperature of 600? and the acid treatment concentration of 60% has the best humidity control performance,and on this basis,the humidity control performance grade of the diatom shale interior wall coating is predicted.In this paper,by designing a formaldehyde purification experiment,the purifying performance of diatom shale interior wall coating on formaldehyde was studied.The results show that only using diatom shale as the purification material can not completely purify the formaldehyde,the purification rate reaches 60.5% at 240min;the formaldehyde purification performance is significantly improved after the nano-TiO₂ is added,and the purification rate reaches 82.1% at 240 min,and the highest formaldehyde concentration Obvious reduction.On this basis,the feasibility of nitrogen-doped TiO₂ was analyzed.