Preparation Of Hollow Nanospheres And Their Use In CO 2 Separation Membranes

The membrane separation is attractive for CO2 caputure because of the inherently low energy requirement.The developments of membrane materials and membranes with outstanding performances are keys to furture growth.Polymer hollow nanoparticles are a type of nanoparticles with hollow and pore structure.Because of its particular hollow structure and the particularity of the preparation method,hollow polymer nanoparticles have many special uses and superior properties.In order to escape the restriction of Robeson upper boundary and obtain high CO2 permeability and high CO2/light gases selectivity simultaneously,The cross-linked polymer was constructed into a hollow nanoparticle with a dense shell and then filled into the traditional polymer membrane.In the process of gas permeation,the polymer/hollow d nanoparticle mixed matrix membranes will be synthesized to strengthen mass transfer process and improve permeation-separation performance.Firstly,tetrahydrofuran acrylate and dipentaerythritol hexaacrylate were used as the oil phase reaction monomer and the cross-linking agent,respectively.In-situ polymerization was used to prepare hollow nanoparticles in surfactant-free microemulsion.After removing the solvent,the hollow nanoparticle membrane is obtained.The prepared hollow nanoparticles,hollow nanoparticle membranes and the material eigenvalue were characterized by FTIR,electron microscopy,dynamic light scattering,differential scanning calorimetry,X-ray diffraction and small-angle X-ray scattering.The effects of the membrane nanocavity on the gas permeability and selectivity of the separation membrane was investigated.The results showed that the prepared hollow nanoparticles have a diameter of 150±20 nm,a hollow structure and a shell thickness of 10-20 nm.The prepared hollow nanoparticles have a significantly higher permeability than the material eigenvalue.In the condition of 35℃,0.2 MPa,without sacrificing the selectivity,the permeability coefficient of CO2 of hollow nanoparticle membrane increased by 1.4-5.7 times than the material eigenvalue,and the permeability of 35 wt%crosslinker gas membrane increased most significantly.Then PEO hollow nanoparticles were prepared by interfacial polymerization using polyethylene glycol methyl ether acrylate and dipentaerythritol hexaacrylate as the water phase monomer and the oil phase crosslinking agent respectively.After removing the solvent,the hollow nanoparticle membrane is obtained.And the gas permeability of the hollow nanoparticle membrane and the material eigenvalue were investigated.The results showed that the hollow nanoparticle membrane with 50%cross-linking agent increased most significantly,the permeability coefficient of N2 increased from 1.06 Barrer to 4.33 Barrer,increased by 4.1 times and the permeability coefficient of CO2 increased from 43.2 Barter to 197 Barrer,increased by 4.5 times.And further by filling the PEO hollow nanoparticles into the polymer matrix with the same chemical composition a series of mixed matrix membrane was prepared,the prepared mixed matrix membrane permeability coefficient of N2 and CO2 are increased by pure polymer membrane 2-4 times,and the membrane can maintain good separation performance.