Research On Preparation Of Chinese Ink Nanofluid And Solar Thermal Desalination Application

With the declining of freshwater resources and the increasing demand for freshwater resources from the rapid development of society,the shortage of freshwater resources has gradually become a worldwide problem facing mankind.At present,the desalination is one of the effective ways to solve this problem.Compared with the traditional desalination technology,the solar thermal desalination system based on nano-materials has the characteristics of environmental friend,low cost,high efficiency and excellent water quality,so it has great research and application potential.The excellent performance of light-absorbing materials and evaporation device is crucial in the solar thermal desalination system.This work proposes to apply Chinese ink,a treasure of Chinese traditional culture,as a light absorbing material for solar thermal desalination.Not only the Chinese ink nanofluid is prepared,but also its optical properties and the factors affecting its dispersion stability are investigated.It is proved that the Chinese ink nanofluid has excellent absorption and low transmission,and it is obvious that the Chinese ink nanofluid has broadband spectral absorption.With the increase of the mass fraction,the light absorption properties of the Chinese ink nanofluid also increase.At the same time,ultrasonic dispersion and dispersion base fluid have a great impact on its stability.Based on the excellent optical properties and dispersion stability of Chinese ink nanofluid,the evaporation rate can be increased obviously when Chinese ink nanofluid is used as heat collecting medium in solar thermal desalination.With the increase of mass fraction,the evaporation rate tends to rise first and then decrease,Compared with other mass fractions,Pine-soot ink nanofluid and Tung-oil ink nanofluid have a higher evaporation rate at 0.25%,the evaporation rate is 1.76 and 1.71 times higher than natural evaporation.Furthermore,the Chinese ink/polylactic acid composite fibrous membrane is prepared by electrospinning and a three-layer interface evaporation device is designed.It has greatly improved the water evaporation performance by the device due to the excellent photo-thermal conversion characteristics of Chinese ink and the high specific surface area of fibrous membrane.When the mass fraction of Chinese ink nanoparticles in the fibrous membrane is 2%,the evaporation rate and evaporation efficiency are 1.29 kg·m-2 · h-1 and 81.0%respectively.In addition,the device has remarkable durability and thermal stability,which makes it has a wide range of application prospects in desalination,sewage treatment and so on.