Research And Design Of Photothermal Materials And Application Equipment Based On Novel Polydopamine

With the continuous development and progress of society,the demand and consumption of fresh water and energy in various fields are increasing day by day,and the lack of these resources even causes the energy and freshwater crisis.Seawater resources,which account for 97%of surface water resources,have become an important way for people to solve the freshwater crisis,so desalination treatment technology has gradually attracted people’s attention.However,the traditional desalination equipment is complex and has high energy consumption,so the development of the application of new energy technology in desalination is an effective means to solve the energy crisis and freshwater crisis.In this study,a new type of polydopamine photothermal conversion film was developed,and energy-self-sufficient water desalination equipment was designed based on the membrane material,which realized the integrated innovation and application of photothermal materials and new energy equipment.Polydopamine has similar absorbance properties to melanin,and is a widely concerned polymer near-infrared absorbing material,which has good prospects in photothermal conversion.However,due to its diverse polymerization mechanism and complex internal structure,there are few studies on the functional design of polydopamine.In this study,the light-absorbing properties and hydrophilicity of polydopamine were improved by designing Fe3+and silane coupling agents to react with dopamine.Furthermore,in this study,the synthesized nanoparticles were vacuum filtered,stacked to construct hydrophilic transport channels,and formed a nanomicrogrid structure,which realized the photothermal conversion membrane structure of light capture and bihydrophilic effects.X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FTIR)and water contact angle test characterization proved that this study successfully synthesized high-absorbance hydrophilic polydopamine nanoparticles with an absorbance of 90%.Experiments show that under a solar intensity,the water evaporation experiment using the photothermal film designed in this paper can reach 1.1 kg/(m2·h),and the photothermal conversion efficiency is 80%,and the salt water desalination effect of the combined material is found to be very excellent through the salinity test of water quality in the experiment,so it has a good application prospect in the field of seawater desalination.Furthermore,according to the new polydopamine photothermal conversion membrane material developed in this study,an energy-self-sufficient seawater desalination equipment was designed,which combined the photothermal conversion material with the new energy system.This equipment belongs to the solar humidification-dehumidification seawater desalination system,using the Arduino Nano development board as the control core,and the overall energy of the equipment is powered by photovoltaic panels to achieve energy self-sufficiency.The equipment structure is mainly composed of three parts:photothermal evaporation area,condenser and device installation area.First,the photothermal film material is loaded into the photothermal evaporation chamber and concentrated through the Fresnel lens,and the generated freshwater vapor is circulated into the condenser through a vacuum pump.At the same time,the photoresistor analog signal is read,and the vacuum pump PWM adaptive power adjustment is realized according to the change of the photosensitive signal value.When the water level sensor obtains the water full signal,the self-priming water pump draws the water from the reservoir to the application.The whole process is verified by circuit simulation,and finally the actual effect of the device is proved through the overall assembly of the equipment.The photothermal evaporation rate of the equipment is 1.29 kg/(m2·h),which is about 20%higher than that of a single photothermal film material.This study successfully developed new materials for photothermal conversion and carried out specific experiments and equipment design combined with renewable energy,which confirmed its function and effectiveness,and provided useful ideas and technical methods for practical application in the field of seawater desalination.