Reconfiguring Molecular Conformation from Comb-Type to Y-Type for Improving Dispersion Performance of Polycarboxylate Superplasticizers,Macromolecules

当前位置： X-MOL 学术 › Macromolecules › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Reconfiguring Molecular Conformation from Comb-Type to Y-Type for Improving Dispersion Performance of Polycarboxylate Superplasticizers
Macromolecules ( IF 5.1 ) Pub Date : 2024-01-11 , DOI: 10.1021/acs.macromol.3c01759
Tianfeng Zhou ₁ , Haotian Duan ₁ , Zhenzhong Li ₁ , Yu Jin ₁ , Hai Liu ₁ , Yuxia Pang ₁ , Hongming Lou ₁ , Dongjie Yang ₁ , Xueqing Qiu ₂

Affiliation

Steric repulsive force is the main dispersion force between cement particles. In order to improve the dispersibility of polycarboxylate superplasticizers (PCEs), we designed and synthesized a new Y-type macromonomer (YPEG) with a molecular weight of M_w = 4100 Da. A long side chain-branched polycarboxylate superplasticizer (YPCE) was successfully synthesized by employing YPEG. Several common comb PCEs having the same side chain density but different lengths, such as PCE2400 and PCE4000, are employed to compare with YPCE for evaluating the dispersion performance. The results show that YPCE has a more excellent dispersion performance than the common PCEs under different water–cement ratios. Additionally, YPCE shows stronger water reduction for concrete. Furthermore, a dynamic light scattering study elucidates that YPCE can increase the adsorbed layer thickness from 5.6 to 7.9 nm, thus forming stronger steric hindrance. Simulations using molecular dynamics are conducted to investigate the influence of the conformational transformation of PCEs from comb-type to Y-type on the adsorption configuration and radius of gyration (R_g) of PCEs on calcium silicate hydrate surface. It is observed that the side chain of YPCE remains in an extended state, and R_g fluctuates little during the fitting process. This study provides a new strategy to enhance the steric hindrance of PCEs.

中文翻译：

将分子构象从梳型重构为 Y 型以提高聚羧酸减水剂的分散性能

位阻排斥力是水泥颗粒之间的主要分散力。为了提高聚羧酸减水剂（PCE）的分散性，我们设计并合成了一种分子量为M _w = 4100 Da的新型Y型大分子单体（YPEG）。利用YPEG成功合成了长侧链支化聚羧酸减水剂(YPCE)。采用几种具有相同侧链密度但不同长度的常见梳状PCE，例如PCE2400和PCE4000，与YPCE进行比较以评估分散性能。结果表明，在不同水灰比下，YPCE比普通PCE具有更优异的分散性能。此外，YPCE 对混凝土的减水效果更强。此外，动态光散射研究表明，YPCE 可以将吸附层厚度从 5.6 nm 增加至 7.9 nm，从而形成更强的空间位阻。利用分子动力学模拟研究了PCEs从梳型到Y型的构象转变对PCEs在硅酸钙水合物表面的吸附构型和回转半径( R _{g )的影响。}观察到YPCE的侧链保持延伸状态，并且R _g在拟合过程中波动很小。这项研究提供了增强PCE空间位阻的新策略。

更新日期：2024-01-11

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南