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This study investigates the relationship between the molecular structure and foaming of poly(ethylene glycol) and poly(propylene glycol) triblock copolymers in Portland cement pastes. Four copolymers with different molecular structures were studied at varying concentrations. All copolymers showed a reduction in surface tension of the cement pore solution; however, only some of them demonstrated foaming and air entraining in cement paste. The results indicated that the molecular structure parameter, hydrophilic-to-lipophilic balance (HLB), has a direct relationship with the foaming and air-entraining performance of the copolymers. The total organic carbon measurements showed very small adsorption of these non-ionic copolymers on hydrating cement particles due to the lack of surface charge needed to interact with the heterogeneously charged surface of hydrating cement. In addition, these copolymers did not seem to affect the flow of cement paste due to a lack of adsorption on cement particles. The cement paste modified with the copolymers showed increased water sorption compared to the control paste due to the increased capillary porosity and slight increase in pore surface hydrophilicity. However, the freeze-thaw resistance was shown to improve with an increase in the number of air voids in the modified cement pastes. The findings establish the relationship between molecular properties of copolymers and their air-entraining performance in cement paste to mitigate the damages caused by freeze-thaw action.
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This content will become publicly available on August 5, 2026
Predicting air‐entraining in cement paste from the molecular attributes of nonionic surfactants with a multilayer method
Abstract The novelty of this study is to present a multilayer framework for predicting the air‐entrained porosity of cement paste based on the molecular characteristics of nonionic surfactants. Air‐entraining agents enhance concrete durability against freeze–thaw damage; however, their development is labor‐intensive and cost‐prohibitive. This research implements a multilayer approach by incorporating three hierarchical layers: the molecular properties of nonionic surfactants (Layer 1), their physicochemical characteristics (Layer 2), and the air‐entrained microstructural porosity of hardened cement paste (Layer 3). By integrating key molecular parameters—such as hydrocarbon chain length, hydrophobicity, and molecular weight—this model effectively predicts the air‐entrained porosity of cement paste. An extensive experimental study was conducted to characterize the physicochemical and microstructural properties of 59 distinct nonionic surfactants. To the best of our knowledge, this represents the first comprehensive dataset of molecular and physicochemical properties of air‐entraining agents reported in the literature. Moreover, no prior study has established such a detailed link between the molecular characteristics of nonionic surfactants and cement microstructure. This dataset served as the foundation for developing the predictive model, which demonstrated the feasibility of this approach in predicting the air‐entraining performance of nonionic admixtures. The developed model facilitates the rapid screening of candidate surfactants and the optimization of their molecular structure while minimizing the need for extensive experimentation. Furthermore, distinct trends emerged from the dataset, offering new insights into the interdependent properties that govern air entrainment in cementitious materials.
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- Award ID(s):
- 1920127
- PAR ID:
- 10631151
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Journal of the American Ceramic Society
- ISSN:
- 0002-7820
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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