Design Of Three-dimensional Hollow Structure Adsorbent To Separate Acteoside

Acteoside(ACT)is the main active component of phenylethanol glycosides(Ph Gs),which are the main functional component of Cistanche tubulosa.It has anti-inflammatory,liver protection and neuroprotective pharmacological activities.However,it is challenging to adsorb ACT efficiently because of the low content of ACT in Cistanche tubulosa and the complex composition and similar molecular structure in Cistanche tubulosa.Therefore,the development of adsorbent with excellent adsorption performance is the key to achieve efficient separation of ACT.In this thesis,a series of three-dimensional hollow structure adsorbents were designed and prepared for the separation of ACT.By adjusting the physical and chemical structure of the adsorbent,the effects of different morphology,specific surface area and functional groups of the adsorbent on the adsorption of ACT were investigated,and the efficient separation of ACT was achieved.The specific research contents of this thesis are as follows:(1)The three-dimensional hollow carbon spheres(HCS)were designed and prepared for the separation of ACT.The as-prepared HCS showed a multi-mesoporous hollow shell structure.The performance of threedimensional HCS was compared with that of one-dimensional SWNT and two-dimensional GPE,and it was found that three-dimensional HCS had the best performance.This was mainly attributed to as follow: on the one hand,HCS had multi-mesoporous hollow shell structure,which increased the path of ACT transmission to the interior,and increased the effective space to accommodate and absorb ACT,improving the adsorption performance of ACT;On the other hand,the surface of HCS had-NH groups,which was conducive to improve the affinity between HCS and ACT,realizing the separation of ACT.The results showed that the adsorption capacity and selectivity of HCS for ACT were 369.98 mg/g and 2.3,respectively.After 8 cycles of adsorption and desorption experiments,the adsorption capacity of HCS remained above 85% of the initial adsorption capacity.(2)The three-dimensional hollow polymer nanospheres(HPN)were designed and prepared for the adsorption of ACT.The as-prepared HPN presented a polyhydroxyl hollow spiny spherical structure with a large hollow cavity,and HPN-2 showed excellent adsorption performance.It was mainly attributed to the following two aspects: on the one hand,HPN-2 presented a hollow spiny spherical structure,and the large hollow cavity increased the specific surface area,which provided sufficient space for accommodating and adsorbing ACT,improving the adsorption capacity of ACT;On the other hand,the surface of HPN-2 had abundant-OH groups and other functional groups.It provided more affinity sites and enhanced the affinity between HPN-2 and ACT,thus realizing the selective adsorption for ACT.The results indicated that the adsorption capacity and selectivity of HPN-2 for ACT were 323.64 mg/g and 3.77,respectively.The HPN-2showed excellent regeneration performance,after 8 cycles of adsorption and desorption experiments.(3)The three-dimensional multichambered cubic box(MCB)was designed and prepared for the separation of ACT.The as-prepared MCB consisted of porous carbon shells on the outside and connected carbon grids with a hollow structure on the inside.It presented a multichambered hollow square box structure,and MCB-2.5 showed the optimal adsorption performance.It could attribute to the following reasons: MCB-2.5 has a multichambered hollow square box structure,which greatly improved the specific surface area and pore volume.This not only increased the effective cavity for adsorption of ACT but also improved additional adsorption sites,improving the adsorption performance of ACT;On the other hand,abundant imidazole rings were distributed on the shell and inner cavity wall skeleton of MCB-2.5,which increased the affinity between MCB-2.5 and ACT,improving the adsorption capacity for ACT.The results indicated that the adsorption capacity and selectivity of MCB-2.5 for ACT were 783.89 mg/g and 1.11,respectively.After eight adsorption-desorption cycles,the adsorption capacity of MCB-2.5 maintained above 85% of the initial adsorption capacity.