Materials
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2022
·Vol. 15
·期 21
·7492
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IF 3.748
Min Qiao,Jingzhi Wu,Nanxiao Gao,Guangcheng Shan,Fei Shen,Jian Chen,Bosong Zhu
In this study, a series of polyether-type defoamers for concrete which consist of the same alkyl chain (hydrophobic part) but different polyether chains (hydrophilic part) was prepared, and the structure–property relationship of the defoamers was investigated for the first time. Using oleyl alcohol (OA) as the starting agent (alkyl chain), the polyether defoamers with different polyether chains were prepared by changing the amount and sequence of ethylene oxide (EO) and propylene oxide (PO) units. The properties of different defoamers were tested in aqueous solutions, and fresh and hardened mortars; the structure–property relationship of the defoamers was thus studied. The results indicated that the defoaming capacity of the polyether defoamers decreased with an increased EO amount, and the defoamers linked with both EO and PO units (PO before EO) had a stronger defoaming capacity than those linked with EO only. This study is beneficial for the development and applications of novel synthetic polyether-type defoamers for concrete.Keywords:polyether;defoamer;bubble;air void;mortar;concrete
研究领域:
建筑材料学
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化学工程
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DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2023
·
IF 9.9
Yonggan Ju,Jingxian Hua,Yawei Gu,Hongling Chen
Foams can be seen everywhere in human production and life. An uncontrolled foam event usually leads to product losses, equipment damage, and clean-up costs. Defoamer is one of the most effective strategies to eliminate or inhibit foam activities, which has been proved by long-term practices. In this work, we report new molecular defoamers with high-branched structure, which adopts melamine molecule as the parent structure, by incorporating alkyl-isocyanates with different chain lengths into the high-branched melamine derivatives (Hb-MDs) formula to replace the R − NH 2 (primary ammonia) on melamine structure. The substitution reaction processes can be readily tuned by varying the molar ratio or alkyl chain length of alkyl-isocyanate, enabling a facile control over the branched degree. The foam tests reveal that the high-branched melamine molecule defoamers exhibited excellent defoaming and anti-foaming properties for four typical foam systems, including an anionic SDBS , cationic DTAB , non-ionic AEO-9, and white cat (BM) detergent, with efficiency close to that of silicone-type LN1414 defoamer and far superior to that of high-carbon alcohol XS-02 defoamer, at the same addition level. Notably, the defoaming or anti-foaming performances of the high-branched melamine molecule defoamers were not always monotonically increased with the branched degree or hydrophobic chain length, but a suitable range needed to be maintained to support a good balance of defoamer structure with foam liquid films . Therefore, it is anticipated that this high-branched design principle could open a new avenue for the construction of molecular defoamers for complex industrial problems.
研究领域:
化学工程
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材料科学
·
表面化学
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DOI
PubMed
高影响因子
LANGMUIR
·
2023
·
IF 3.9
Yonggan Ju,Jingxian Hua,Hong Niu,Hongling Chen
Bubbles or foams appear in many industrial processes, bringing inconvenience; yet, efficient capture or removal of them is still challenging. In this study, we report the synthesis and properties of multibranched molecule defoamers based on methyl gallate derivatives (Mb-GDs), which adopt methyl gallate (M-G) as the parent structure, by incorporating alkyl groups from alkyl isocyanates (A-I) with different chain lengths (C12 and C18) to replace R–OH in the M-G structure and further by linking two Mb-GDs into one Gemini-type multibranched derivative (Gt-Mb-GD) by transesterification to construct a defoamer material with a larger spatial volume. The surface properties and interfacial activity of molecular defoamers in aqueous solutions were studied, and the structure–property relationships of the multibranched gallate molecule defoamers based on Mb-GDs and Gt-Mb-GDs were further investigated by comparing the defoaming and antifoaming performance in four typical surfactant foams and foaming solutions with two kinds of commercial defoamers. The foam experiments indicated that the defoamers with a longer branched chain length (C18) showed more effectiveness in defoaming and antifoaming for four surfactant foams or foaming solutions, even at very low dosages, which were far stronger than the commercial high-carbon alcohol defoamer with a linear structure and comparable to branched silicone-based emulsion-type defoamers. Compared with Mb-GD defoamers, Gt-Mb-GD defoamers with a larger branched structure showed a higher defoaming performance. The study found the great potential of materials with multibranched structures for practical applications as the core components of high-performance defoamers.
研究领域:
化学
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材料科学
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工业化学
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DOI
PubMed
高影响因子
JOURNAL OF SURFACTANTS AND DETERGENTS
·
2024
·
IF 1.6
Yifei Gao,Jian Wang,Dehua Xu,Yuxuan Lin,Wenbao Song,Yubo Wang,Fei Xu,Gang Chen
In this article, polyether-modified polysiloxanes were synthesized by the reaction of poly(methyl hydrogen siloxane) (PMHS) with Allyl alcohol polyether B-400. FT-IR, laser particle size analysis, hydrophilic–lipophilic balance (HLB) value test, and surface tension measurements were used to characterize its structures and properties. The results show that the control law for the HLB value of polyether-modified polysiloxanes was obtained as follow: the HLB value increases with increasing hydrogen content of PMHS. When the polyether-modified polysiloxanes were used to emulsify the polysiloxane, at the HLB value of 10.5, the average particle size of the emulsion was about 0.23 μm with a narrow particle size distribution. The emulsion has good emulsifying and dispersing properties, as well as excellent foam elimination and foam inhibition performance. When the cellulose nanofibrils (CNF) was used as a protective agent for the preparing of the polysiloxane defoamer, the stability of the emulsion does not affect, but its foam elimination and foam inhibition of emulsion can be further improved at the presence of CNF. The lowest surface tension of CNF-enhanced polyether-modified polysiloxane defoamer is about 22.4 mN m −1 , which has good surface property. When the concentration of CNF-enhanced polyether-modified polysiloxane defoamer was 0.1 g L −1 , the foam elimination time and foam inhibition time were 5.8 s and 38 min, respectively, at the temperature (80°C) and alkali environment (pH 13).
研究领域:
材料科学
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化学工程
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DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
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2020
·
IF 4.469
Zhong Liang,Jiantao Zhu,Fuqiang Li,Zhimin Wu,Yuejin Liu,Di Xiong
In this paper, a series of self-crosslinking waterborne polyurethane (WPU) dispersions with side chain, which is (3-(2-Aminoethyl)aminopropyl)trimethoxysilane (AEAPTMS) as the diamine chain extender, were prepared. The characteristics of WPU with different dosages of AEAPTMS were evaluated, including particle size, crystallinity, surface performance, water resistance and thermal stability. It was demonstrated that AEAPTMS was successfully incorporated into the WPU from Fourier-transform infrared spectroscopy (FT-IR). Once the content of AEAPTMS increased to 5 %, the WPU dispersions became gelatinous. That is, the siloxane groups were hydrolyzed into a cross-linked structure during the emulsification process. The particle size enlarged with the increasing dosage of AEAPTMS in transmission electron microscopy (TEM). The X-ray photoelectron spectroscopy showed that the silane in the cross-linked WPU migrated freely towards the WPU film surface. The addition of AEAPTMS enhanced the tensile strength, hydrophobicity, water resistance and thermal stability of WPU film. Meanwhile, the elongation at break and crystallinity of WPU films were declined. Besides, interestingly, the glass transition temperature of WPU films followed the trend of first rising and then falling. By adding wetting agent, antifoaming agent, adhesion promoter and flatting agent into WPU, the water-based varnish was prepared. The pencil hardness, water resistance, adhesion and anti-adhesion of water-based varnish were best in the application on the stainless steel substrate when the WPU sample was Si-WPU-3.
研究领域:
高分子科学
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材料科学
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表面化学
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涂料技术
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DOI
高影响因子
危险品化学品经营许可证（带存储）