Hansen Solubility Parameters Determination And Application Of Modified Halloysite Nanotubes And MXene

Halloysite nanotubes(HNTs)and transition metal carbonitrides(MXene),as one-dimensional and two-dimensional nanomaterials,are widely studied due to their excellent physical and chemical properties.They are usually used in a composite system with different solvents or polymers,and their dispersibility in solvents or polymers is particularly important.The surface state of the nanomaterial before and after modification has a great influence on its dispersion in a media.How to determine a parameter to characterize the correlation between the surface properties of nanomaterial and the dispersibility is still an important issue.Hansen solubility parameters(HSPs)can be used to describe the degree of interaction between different materials,and are of great significance to the prediction and evaluation of the dispersibility of nanomaterials in different solvents or polymers.Some nanomaterials,such as graphene and carbon nanotubes,have received much attention.Their dispersibility and Hansen solubility parameters have been studied detailed,but there are few related reports on HNTs and MXene.Therefore,this paper mainly studies the dispersibility of HNTs and MXene in dozens of organic solvents,and Hansen solubility parameters of them were further calculated based on the dispersibility results which enriches the Hansen solubility parameter database of nanomaterials.In addition,Hansen solubility parameter theory was used to predict the nanomaterials dispersibility in different polymers,and the relationship between the dispersibility of nanomaterials and the properties of composites was also explored which provides a necessary theoretical basis for the practical application of HNTs and MXene.The main research contents and results of this paper are as follows:(1)The dispersibility of HNTs in various organic solvents was investigated,and the Hansen solubility parameters were calculated based on the results of the dispersibility of HNTs in solvents.Hansen solubility parameter theory was used to predict the compatibility between HNTs and polyethylene oxide(PEO).The results show that HNTs have good dispersibility in the PEO matrix,and the thermal stability of the composite has been improved.(2)HNTs were modified using KH550 and octadecylamine(ODA),respectively.The dispersibility of the modified HNTs in various solvents were investigated,and their Hansen solubility parameters were calculated using MATLAB software.Hansen solubility parameters of HNTs are?_d=15.1 MPa^1/2,?_p=18.8 MPa^1/2and?_h=19.5MPa^1/2,Hansen solubility parameters of HNTs-KH550 are?_d=17.8 MPa^1/2,?_p=9.7MPa^1/2and?_h=15.3 MPa^1/2,Hansen solubility parameters of HNTs-ODA are?_d=16.6MPa^1/2,?_p=8.5 MPa^1/2and?_h=13.5 MPa^1/2.Based on the Hansen solubility parameter theory,the dispersibility of HNTs and modified HNTs in three different polar polymers of PEO,polymethyl methacrylate(PMMA)and polypropylene(PP)is predicted.The results show that the dispersibility is basically consistent with the forecast.(3)The dispersibility of Ti₃C₂T_xMXene in 43 organic solvents was investigated,and Hanen solubility parameters of MXene were measured of?_d=18.7 MPa^1/2,?_p=15.4 MPa^1/2and?_h=14.5 MPa^1/2using the MATLAB software.With the aid of Hansen solubility parameter theory,a binary water/acetone mixed solvent of MXene was designed.When the ratio of water/acetone is 60/40,the HSPs of the mixed solvent is closest to that of MXene,which can effectively exfoliated MXene into a few-layers and single-layer nanosheets.The long-term storage stability of MXene in the mixed solvent is also improved.(4)The surface of Ti₃C₂T_xMXene was modified with cationic surfactants including tetrabutylammonium bromide(TBAB)and cetyltrimethylammonium bromide(CTAB),and the dispersibility of modified MXene in various solvents was investigated.In addition,the Hansen solubility parameters of modified MXene are calculated using the MATLAB software.Hansen solubility parameters of MXene-TBAB are?_d=17.2 MPa^1/2,?_p=9.1 MPa^1/2and?_h=7.0 MPa^1/2,the Hansen solubility parameters of MXene-CTAB are?_d=17.8 MPa^1/2,?_p=9.8 MPa^1/2and?_h=3.6MPa^1/2.Based on the Hansen solubility parameter theory,the dispersibility of MXene and modified MXene in three polymers of PEO,PMMA,and PP is predicted.The morphology of the composites shows that the dispersibility of MXene and modified MXene in these polymers are consistent with the prediction.Simultaneously,the mechanical properties and electrical conductivity of the composites change accordingly.