南京大学学报（自然科学版）2019，Vol.55Issue(2)：291-300,10.DOI:10.13232/j.cnki.jnju.2019.02.014
泥岩中的有机质对基于XRD的伊蒙混层结构计算的影响
The effect of organic matter on the calculation of structure details of illite/smectite in mudstones using XRD
摘要
Abstract
We applied two organic matter removal methods to determine the effect of organic matter (OM)on the characterization and calculation of structural details of illite/smectite mixed layer mineral using XRD.A similar XRD pattern was observed between UT(untreated sample)and HT(OM removal with hydrogen peroxide(H2 O2-30%)). In contrast,NT(OM removal with disodium peroxodisulfate(Na2 S2 O8 ))showed a different XRD pattern including peaks at 15 ?(AD,Air-dried)and 1 6.7 ?(EG,Ethylene glycol-saturated)which were not observed in the XRD patterns of UT and HT.In addition,after OM removal with Na2 S2 O8 treatment,the d001|001 and d002|003 peaks of I/S shifted to a higher 2-Theta angle and its d001|002 peak shifted to a lower angle,denoting an improved expandability both in AD and EG condition.A multi-specimen fitting model applied to their AD and EG patterns also suggested a much higher proportion of expandable layers after Na2 S2 O8 treatment.This inconsistency could be explained by the occurrence of interlayer OM in smectite layers rendering them hydrophobic,thus blocking the intercalation of water molecules and polar ethylene glycol molecules.This highly proscribes the expandability of parts of smectite layers in the AD and EG conditions and leads to an underestimate of the proportion of smectite layers in I/S.Our results clearly show that,compared to H2 O2 ,Na2 S2 O8 could be more efficient in removing the inhibiting effect of interlayer OM on smectite expandability when exposed to water and polar organic molecules,which would guarantee a more precise characterization and calculation of structural details of I/S using XRD.关键词
XRD/有机质/伊蒙混层/混层比/结构计算Key words
XRD/organic matter/illite/smectite/smectite layer in I/S/structure characterization分类
天文与地球科学引用本文复制引用
巢前,蔡进功,李艳丽,王国力..泥岩中的有机质对基于XRD的伊蒙混层结构计算的影响[J].南京大学学报（自然科学版）,2019,55(2):291-300,10.基金项目
国家自然科学基金(41672115),国家油气重大专项(2016ZX05006001-003) （41672115）
