Insights Into The Adsorption Performances Of Organo-vermiculites And Organo Silica Nanosheets

The research of the adsorption property of organo clays has always been the hotspot of water remediation,which owns great guidance for the development of cost-effective adsorbents.Novel organo-vermiculites（organo-Vt）and organo silica nanosheets（organo-SiNSs）are prepared for the first time in this study.The surface and structure of the resultant organo-Vts and organo-SiNSs are characterized by Fourier transform infrared spectroscopy（FT-IR）,X-ray diffraction（XRD）,elemental analysis（EA）,thermogravimetric analysis（TG）,electron microscopy（SEM and TEM）and surface areas analysis（BET）.Bisphenol A（BPA）and benzoic acid（BA）are chosen as models for the adsorption properties of the resultants.Organo-Vts with biphenyl or dipyridyl functional groups are successfully prepared.The saturated surfactant dosage in the modification process of Vt,in reverse relationship with the availability of the modifier,was defined as low as 0.4 CEC.The d001 spacings of BHBP-Vt are larger than DHBP-Vt.The adsorption performances of organo-Vts are tested by bisphenol A（BPA）,which show great potential as organic adsorbents(143.5 mg g^-1 and 139.7 mg g^-1 for BHBP-Vt and DHBP-Vt,respectively).π-πinteractions between aromatic rings are stronger than that between heteroaromatic ring and aromatic ring,andπ-πstacking between the BPA adsorbed and dissociative in solution turn out to promote the adsorption process.Organo-SiNSs with aromatic or hydroxyl groups are firstly prepared in this study.the d001 spacing of BHPD-SiNSs are larger than that of BHHP-SiNSs,which may be due to the larger dosage of the loaded modifier for BHPD,derived from the strongerπ-πinteraction within the functional group of BHPD compared with BHHP.For organo-SiNSs,enhanced adsorption yields god potential from the standpoint of rapid adsorption within 10 min.The adsorption capacity of BHPD-SiNSs(81.72 mg g^-1)higher than that of BHHP-SiNSs(54.88 mg g^-1),which verifies the strength:π-πinteraction>hydrogen bond.Kinetics,isotherm and thermodynamics on the adsorption properties of organo-Vts and organo-SiNSs are also conducted for adsorption mechanism.The adsorption process is sustainable as the spent adsorbents could regenerate by simple ethanol or acid pickling at least for three cycles.