Preparation And Properties Of Halloysite Aerogels As Multi-scale Drug Carriers

Halloysite(HNTs)is a tubular structure,which is naturally curled by the silicates under the natural conditions.It has high specific surface area,unique adsorption and chemical thermal stability,as well as unique nanostructure and structural properties.HNTs has a wide distribution,low price and good biocompatibility.It makes up the existing nanomaterials,such as the shortage of carbon nanotubes,and makes HNTs a promising natural nanomaterial.In this paper,the macromolecular chains were loaded on the inner wall of HNTs through the interaction between the positive charge of inner wall and the negative charge on polymer molecular chain.The loaded macromolecular chains were used as the crosslinking point.The Pickering emulsion method is used to construct three-dimensional aerogel networks.The loading behavior of macromolecular chains and the construction of aerogels were studied by using of FTIR,TGA,Zeta potential,SEM,and so on.The obtained multi-scale characteristics of the pores of the inner cavity and aerogel pores of the nanotube,ibuprofen and dexamethasone were loaded into different pores respectively.The drug loading materials with macropore and mesopore were prepared,and theie drug loading effect was studied.The results showed that polysiloxane was successfully loaded in the cavity of the HNTs by electrostatic interaction.The specific surface area of HNTs were reduced,the pore size was significantly decreased,and concentrated and uniform pore distribution was formed by the loading of polysiloxane.The adsorption isotherms of these materials are IV type IUPAC isotherms,and the pore size is mainly mesoporous.The cavity of the halloysite nanoparticles was blocked by ibuprofen and interrupted by gaps.When the two drugs were loaded at the pore of the clay aerogel with macropore and mesopore,it showed a relatively uniform drug release rate,reflecting the excellent drug loading performance of the drug loading material of the clay nanotube.The release force of the drug was related to the pH value.The greater the acidity at the same time,the greater the release rate of the drug.So it was reasonable and feasible to use halloysite clay aerogel as a new drug loading system.