Investigation On Preparation And Device Of Glass Fiber Based Interfacial Evaporation Material For Desalination

Solar-thermal interface water evaporation is an important way to solve the shortage of water resources.The photothermal membrane,as the core component of solar interface evaporator,is mainly composed of photothermal material(absorbing sunlight)and substrate(support and water transport).However,the common substrates are mainly made of cellulose,polypropylene,polyethylene and other materials.Under the condition of high temperature,high salt and corrosion for a long time,the mechanical strength of photothermal membrane and the evaporation performance is easy to decreases.In this paper,the preparation and composition of a novel silicon dioxide/carbon bilayer coaxial photothermal film are reported.fabrication method and their unique compositional attributes.The inner core of the photothermal membrane was constructed by random accumulation of SiO2-based glass fibers.The carbon coating was successfully prepared by carbonizing low-cost linear polyethylene with SiO2-based fibrous membrane as the substrate.The thickness of nano carbon coating can be controlled by temperature.The fabrication process is facile,potentially low-cost,and mass-producible.In comparison with the high reflection(>80%)and low absorption of the glass fibers membrane,the carbon membrane coated with nano carbon has a remarkably high light absorption and a very low reflection(<10%)values in the wavelength range of 400-2500nm,which is mainly attributed to the high light absorption ability of the nanocarbon coating and the large specific surface area(14.9801m2/g)of the photothermal membrane.Taking the glass fiber based carbon membrane as the core module,an interface evaporator was prepared.And the evaporation rate and energy transfer efficiency of the hydrophilic carbon membrane under simulated sunlight irradiation with 1 sun are 1.48 kg·m-2·h-1 and 87.6%,respectively.The evaporation rate is 4.6 times than that of pure water without photothermal membrane and the energy transfer efficiency is 80%higher than that of pure water without photothermal membrane.Taking the interface evaporator as solar evaporator,the seawater evaporation performance was further studied.The evaporator can achieve 1.15kg·m-2·h-1 seawater evaporation efficiency.However,the evaporation performance of the evaporator is easy to decay due to salt accumulation.Here an interface evaporation evaporator with hydrophobic and hydrophilic structure was prepared.The upper layer is made of superhydrophobic carbon membrane(water contact angle=151.8°),and the lower layer is made of super hydrophilic pure glass fiber membrane(water contact angle=0°).The seawater is transported to the interface between the two kinds of fiber membranes,and the salt precipitates in the lower layer super hydrophilic membrane without damaging the photothermal membrane which ensures the stable evaporation of seawater.Taking the interface evaporator as the core component,we designed a new multi-functional and self-sufficient water dispenser device through structural innovation and artistic design.The water dispenser integrates solar photovoltaic technology and solar seawater desalination technology.It has the advantages of multi-function,humanized design and self-sufficiency.It provides a reference for the application of interface evaporator in seawater desalination.