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硅酸盐通报 ›› 2026, Vol. 45 ›› Issue (2): 390-403.DOI: 10.16552/j.cnki.issn1001-1625.2025.0720

• 水泥混凝土 • 上一篇    下一篇

Na-蒙脱石对聚羧酸减水剂的吸附特性及作用机制研究

李盟1(), 孔德松1, 黄腾1,2(), 何智浩3, 王恩文4, 韦云龙1   

  1. 1.西南科技大学环境与资源学院,绵阳 621010
    2.固体废物处理与资源化教育部重点实验室,绵阳 621010
    3.西华大学应急管理学院,成都 610039
    4.安顺学院资源与环境工程学院,安顺 561000
  • 收稿日期:2025-07-23 修订日期:2025-09-19 出版日期:2026-02-20 发布日期:2026-03-09
  • 通信作者: 黄腾,博士,讲师。E-mail:huangheswust@163.com
  • 作者简介:李盟(2000—),男,硕士研究生。主要从事矿物材料方面的研究。E-mail:l13419383953@163.com
  • 基金资助:
    地质灾害防治与地质环境保护国家重点实验室开放基金(SKLGP2022K011);地质灾害防治与地质环境保护国家重点实验室开放基金(SKLGP2023K006);贵州省教育厅创新群体项目(黔教合KY字〔2020〕028)

Adsorption Characteristics and Action Mechanism of Na-Montmorillonite on Polycarboxylate Superplasticizer

LI Meng1(), KONG Desong1, HUANG Teng1,2(), HE Zhihao3, WANG Enwen4, WEI Yunlong1   

  1. 1. School of Environment and Resources,Southwest University of Science and Technology,Mianyang 621010,China
    2. Key Laboratory of Solid Waste Treatment and Resource Recycle,Ministry of Education,Mianyang 621010,China
    3. School of Emergency Management,Xihua University,Chengdu 610039,China
    4. School of Resources and Environmental Engineering,Anshun University,Anshun 561000,China
  • Received:2025-07-23 Revised:2025-09-19 Published:2026-02-20 Online:2026-03-09

摘要:

混凝土集料的泥(以膨润土等黏土矿物为主)与聚羧酸减水剂(PCE)的竞争吸附会对水泥及混凝土性能产生不利影响,本文旨在探究Na-蒙脱石对三种PCE(JSJ-1、JSJ-2、JSJ-3)吸附行为及水泥性能的影响。采用傅里叶变换红外光谱(FT-IR)、核磁共振氢谱(1H-NMR)、凝胶渗透色谱(GPC)表征PCE分子结构与参数,通过水泥净浆试验测定流动度和凝结时间,结合X射线衍射(XRD)、同步热分析(TG-DSC)等表征手段分析吸附后Na-蒙脱石结构变化及吸附机理。结果表明,由于PCE中存在较大分子基团,在Na-蒙脱石掺量为5%(质量分数)时,水泥净浆才会完全失去流动度。吸附动力学研究表明,Na-蒙脱石对三种 PCE 的吸附均符合准二级动力学模型(R2>0.99),以化学吸附为主,最大吸附量依次为338.98 mg/g(JSJ-1)、294.12 mg/g(JSJ-2)、280.90 mg/g(JSJ-3)。Langmuir 等温线拟合结果显示吸附过程为单分子层均匀覆盖(R2>0.99)。吸附后Na-蒙脱石结构分析证实,PCE侧链嵌入Na-蒙脱石层间形成稳定插层结构,使PCE分解温度区间延迟至200~450 ℃。

关键词: Na-蒙脱石, 水泥, 聚羧酸减水剂, 吸附特性, 热力学, 作用机制

Abstract:

The competitive adsorption between the mud (mainly clay minerals such as bentonite) of concrete aggregate and polycarboxylate superplasticizer (PCE) adversely affects the performance of cement and concrete. The purpose of this paper was to explore the effect of Na-montmorillonite on the adsorption behavior of three kinds of PCE (JSJ-1, JSJ-2, JSJ-3) and cement performance. The molecular structure and parameters of PCE were characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance hydrogen spectroscopy (1H-NMR) and gel permeation chromatography (GPC). The fluidity and setting time were measured by cement paste test. The structural changes and adsorption mechanism of Na-montmorillonite after adsorption were analyzed by X-ray diffraction (XRD) and simultaneous thermal analysis (TG-DSC). The results show that the presence of large molecular groups in PCE makes the cement paste completely lose fluidity when the Na-montmorillonite content is 5% (mass fraction). The adsorption kinetics study shows that the adsorption of three types of PCE by Na-montmorillonite conforms to the pseudo-second-order kinetic model (R2>0.99), mainly chemical adsorption, and the maximum adsorption capacity is 338.98 mg/g (JSJ-1), 294.12 mg/g (JSJ-2), 280.90 mg/g (JSJ-3). The Langmuir isotherm fitting results show that the adsorption process is uniformly covered by a monolayer (R2>0.99). The structure analysis of Na-montmorillonite after adsorption confirms that the PCE side chain is embedded in the interlayer of Na-montmorillonite to form a stable intercalation structure, which delays the decomposition temperature range of PCE to 200 ~ 450 °C.

Key words: Na-montmorillonite, cement, polycarboxylate superplasticizer, adsorption characteristic, thermodynamics, action mechanism

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