Processes
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2022
·Vol. 10
·期 6
·1183
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IF 3.352
Haibing Jiang,Jiufen Liu,Huaifa Wang,Runquan Yang,Wenzhi Zhao,Duo Yang,Song Yin,Liang Shen
Foam is essential in the flotation process. However, the gas–liquid–solid three-phase froth produced in the flotation process has very strong stability and is difficult to burst spontaneously. The existence of these froths will reduce the transport capacity of the pulp and affect the working efficiency of subsequent processes, such as filtration of the flotation concentrate. In this study, a new defoaming device is designed by combining mechanical impact with depressurized defoaming and its defoaming mechanism is analyzed theoretically. In addition, the liquid level height and pulp overflow method are applied to characterize the defoaming efficiency of the new defoaming device. The effects of impeller structure, pressure drop, impeller rotation frequency, and aeration rate on defoaming efficiency were studied. The results show that when increasing the pressure drop, the defoaming increases, but it will also enhance the generation of bubbles. The efficiency of combined mechanical–vacuum defoaming technology is superior under low-pressure drop using an SC impeller. Under −1 kpa vacuum condition, it only takes 168 s to eliminate 20 cm flotation froth height with combined mechanical impact, while it takes 453 s under ambient pressure, indicating that under vacuum conditions, the mechanical-defoaming method can significantly improve the defoaming efficiency, and the two have a certain synergistic effect.Keywords:coal;flotation froth;defoaming;vacuum
研究领域:
矿业工程
·
化学工程
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DOI
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
Materials
·
2022
·Vol. 15
·期 21
·7492
·
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
·
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
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表面化学
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DOI
PubMed
高影响因子
JOURNAL OF SURFACTANTS AND DETERGENTS
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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
ACS Omega
·
2020
·
IF 2.87
Jixin Mao,Teng Chen,Li Guo,Shizhao Yang,Xin Xu,Jun Ma,Jianqiang Hu
The foam tendency of aviation coolants (ACs) can be greatly influenced by additives. This study investigates the effect of additives on foam behaviors based on four commercial ACs and glycol aqueous solutions added with different additives. Experimental results show that the foam tendency of ACs can be greatly influenced by surfactants; however, inorganic salts have little effect on foam tendency. The volume of generated foam reaches up to 350 mL after ventilation for an AC with a surfactant, much larger than 40 mL of an AC with an inorganic salt. The surface tension of ACs reduces with the addition of surfactants, the lower the surface tension, the more the foam formation. Furthermore, the presence of arranged surfactants at the gas–solution interface can increase the intermolecular forces and enhance the liquid and viscosity of film elasticity, thereby enhancing the foam stability. Besides, the surfactants would weaken the gas diffusion of foams and affect the defoaming property of ACs accordingly.
研究领域:
化学工程
·
材料科学
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产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2024
·
IF 3.7
Jiacong Wu,Shiyuan Liu,Xinnan Ma,Cailiang Zhang,Chengxiang Feng,Lei Wang,Juan Han,Yun Wang
The current study presents a scalable approach for the preparation of temperature-responsive PEG/SiO2/PNIPAM-PEA Janus particles and, for the first time, investigates their potential applications in stabilizing foam and defoaming by adjusting the temperature. The method utilizes a (W1 + O)/W2 emulsion system, which incorporates appropriate surfactants to stabilize the emulsion and prevent rapid dissolution of the hydrophilic triblock polymer PEG-b-PTEPM-b-PNIPAM in water. The PEG/SiO2/PNIPAM-PEA Janus particles with temperature-responsive characteristics were synthesized in a single step that combined the sol–gel reaction and photoinduced free radical polymerization. The contact angle of the hydrophilic PEG/SiO2/PNIPAM surface was measured to be 54.7 ± 0.1°, while the contact angle of the hydrophobic PEA surface was found to be 122.4 ± 0.1°. By incorporating PEG/SiO2/PNIPAM-PEA Janus particles at a temperature of 25 °C, the foam’s half-life is significantly prolonged from 42 s to nearly 30 min. However, with an increase in temperature to 50 °C, the foam’s half-life rapidly diminished to only 44 s. This innovative application effectively enhances foam stabilization at low temperatures and facilitates the rapid dissipation of foam at high temperatures.
研究领域:
材料科学
·
化学工程
·
胶体与表面化学
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产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2020
·
IF 2.87
Jixin Mao,Teng Chen,Xin Xu,Shizhao Yang,Li Guo,Jun Ma,Ting Yao,Yongliang Xin,Jianqiang Hu
The particulate contamination degree of aviation coolants (ACs) is overestimated commonly because the bubbles in ACs are erroneously recognized as particulate contaminants during the measurement process. In this work, the factors that influence the foam behavior and contamination degree of ACs are investigated. It is evidenced that the foam behavior of ACs is basically unaffected by the ratio of glycol to water of the base solution, which, however, is highly influenced by the organic additive. Also, the more the organic additive arranged at the gas–liquid interface, the lower the surface tension of glycol aqueous (GA) solution and the higher the contamination degree. Furthermore, the foam characteristics and contamination degree of ACs are highly affected by the working conditions, such as airflow, operating temperature, and gas pressure. Besides, the defoaming rate can be accelerated by adding an antifoaming agent or ultrasonic processing; however, the defoaming effect of the natural static method and pressuring positively treatment is disappointing. To further improve the defoaming effect, several efficient synergetic methods of defoaming have been proposed.
研究领域:
化学工程
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材料科学
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产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
·
IF 5.518
Qingwen Dong,Xu Li,Jinxiang Dong
New branched polyoxyethylene surfactants with different hydrophilic head groups have been synthesized from fatty acid derivatives as renewable resources. Through a systematic study of the surfactant properties of the obtained substances, ethoxylated monohydroxy stearic acid methyl ester (12-HMEE n ) with a single hydrophilic head group, similar to commercial Guerbet alcohol polyoxyethylene ether, has been identified as the most promising candidate. It has excellent surfactant properties including good wettability , low foaming, and strong defoaming ability, indicating that it could be useful in industrial cleaning.
研究领域:
化学
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材料科学
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产品关联
DOI
高影响因子
LANGMUIR
·
2025
·
IF 3.9
Yao He,Zexiang Bi,Qiang Zhang,Shuang Lu,Zhijian Huang,Xiaochao Zhang,Xu Li,Jinxiang Dong
Isononanol, a branched aliphatic alcohol, is derived from isobutylene upgradation, encompassing dimerization and hydroformylation. Branched surfactants exhibit lower surface tension, superior wettability, and rapid defoaming compared to linear surfactants. Isononanol (C9–OH) with abundant methyl branching can serve as a hydrophobic tail of branched surfactants, suffering from insufficient lipophilicity due to its short effective chain length. This paper proposes a strategy to extend the hydrophobic tail by grafting one propylene oxide (P1) or butylene oxide (B1) to increase chain length and branching degree with the aim of synthesizing extended multibranched alcohols C9P1–OH and C9B1–OH with purities of 95.3 and 97.2%, respectively. Subsequently, a series of extended multibranched alcohol polyether nonionic surfactants (C9P1En and C9B1En) were synthesized by ethoxylation, with their structures confirmed by Fourier-transform infrared (FT-IR) and 1H NMR and their surfactant properties systematically investigated. The findings indicate that C9P1En and C9B1En exhibited lower γCMC values compared to the isononanol polyether surfactant (C9En), which allows for rapid wetting on a hydrophobic surface, especially C9B1E6 with an initial contact angle of only 54° compared to 80° for C9E6. Also remarkable is the rapid defoaming performance, with C9B1E6 having less than 0.1% of the initial foam volume but C9E6 having up to 50.1% foam volume after 30 s. These surfactant performances provide significant benefits for the potential application of branched nonionic surfactants in the industrial cleaning field.
研究领域:
化学工程
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材料科学
·
表面活性剂研究
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Chunbao Du,Zixi Chang,Hongjiang Yu,Yanan Zhu,Yonghong Ma,Guoyan Ma,Yongli Yan,Chengjun Wang,Wenzhen Wang,Yuan Cheng
Nanoparticle-stabilized foam fluid provided excellent efficiency in tertiary oil recovery, and a more appealing technique is to exploit reusable low-dimensional nanomaterials, which can achieve better oil-displacement efficiency during the period of global decarbonization. Herein, the magnetic quantum dots (MQDs) were synthesized and then modified by a silane-coupling ionic liquid (SIL) to produce unique quantum dots MQDs@SIL. A series of characterizations and foaming measurements reveal that MQDs@SIL with an average surface grafting density of 1.01 functional chains nm −2 at an ultra-low concentration (0.005 wt%) demonstrated distinct foam stability and salt resistance capability, as well as a unique defoaming performance in a constant magnetic field for regulated foam performance at high temperature. The stretched-straight functional chains and adequate hydrophilic-hydrophobic surface of MQDs@SIL substantially favor the nonreversible adsorption of MQDs@SIL on the gas–liquid interface, leading to an increased surface elasticity, and thus an enhanced foam stability. MQDs@SIL-stabilized foam liquid demonstrated exceptional plugging performance and achieved an enhanced oil recovery of 18.2 % in the stage of foam fluid flooding, exceeding most nanoparticle-stabilized foam fluids ever reported. Furthermore, MQDs@SIL with the unique magnetic property provided unique recycling and reusing benefits, emphasizing their potential applications for enhanced oil recovery.
研究领域:
石油工程
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2023
·Vol. 30
·期 6
·1038-1047
·
IF 4.8
Wu Zhongxian,Tao Dongping,Tao Youjun,Jiang Man,Zhang Patrick
We analyzed a novel cationic collector using chemical plant byproducts, such as cetyltrimethylammonium bromide (CTAB) and dibutyl phthalate (DBP). Our aim is to establish a highly effective and economical process for the removal of quartz from collophane. A micro-flotation test with a 25 mg·L −1 collector at pH value of 6–10 demonstrates a considerable difference in the floatability of pure quartz and fluorapatite. Flotation tests for a collophane sample subjected to the first reverse flotation for magnesium removal demonstrates that a rough flotation process (using a 0.4 kg·t −1 new collector at pH = 6) results in a collophane concentrate with 29.33wt% P 2 O 5 grade and 12.66wt% SiO 2 at a 79.69wt% P 2 O 5 recovery, providing desirable results. Mechanism studies using Fourier transform infrared spectroscopy, zeta potential, and contact angle measurements show that the adsorption capacity of the new collector for quartz is higher than that for fluorapatite. The synergistic effect of DBP increases the difference in hydrophobicity between quartz and fluorapatite. The maximum defoaming rate of the novel cationic collector reaches 142.8 mL·min −1 . This is considerably higher than that of a conventional cationic collector.
研究领域:
矿物加工
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化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）