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Wan J, Yu X, Liu J, Li J, Ai T, Yin C, Liu H, Qin R. A special polysaccharide hydrogel coated on Brasenia schreberi: preventive effects against ulcerative colitis via modulation of gut microbiota. Food Funct 2023; 14:3564-3575. [PMID: 36946057 DOI: 10.1039/d2fo03207d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Ulcerative colitis (UC) is a growing health concern in humans, but it can be prevented by using special dietary strategies. Young stems and leaves of Brasenia schreberi (BS) are coated with a special polysaccharide hydrogel (BS mucilage) which can be beneficial for colon health. The aim of this study was to investigate the preventive effects of BS mucilage against UC in a DSS-treated mouse model. Although containing only 0.3% solid content, our research showed that BS mucilage effectively attenuated the disease activity index (DAI) and the spleen index and downregulated IL-1β, IL-18, IL-6 and CAT mRNA levels in DSS-treated mice, which is a promising UC alleviation function. Additionally, BS mucilage also improved the propionate and butyrate levels in mouse feces and alleviated the imbalanced gut microbiota induced by DSS. The abundance of pro-inflammatory and colorectal cancer related bacteria, such as Prevotella, Ruminococcus, Acutalibacter and Christensenella, was decreased by BS mucilage feeding, whereas the abundance of anti-inflammatory and SCFA-producing bacteria including Alistipes and Odoribacter was increased. In conclusion, the current study shows that the daily consumption of BS mucilage could be an effective way to prevent UC in mice, via modulation of gut microbiota.
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Affiliation(s)
- Jiawei Wan
- Hubei Provincial Key Laboratory for Protection and Application of Special Plant Germplasm in Wuling Area of China, College of Life Sciences, South-Central Minzu University, Wuhan, 430070, China.
| | - Xiujuan Yu
- Hubei Provincial Key Laboratory for Protection and Application of Special Plant Germplasm in Wuling Area of China, College of Life Sciences, South-Central Minzu University, Wuhan, 430070, China.
| | - Jiao Liu
- Hubei Provincial Key Laboratory for Protection and Application of Special Plant Germplasm in Wuling Area of China, College of Life Sciences, South-Central Minzu University, Wuhan, 430070, China.
| | - Jing Li
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Tingyang Ai
- Hubei Provincial Key Laboratory for Protection and Application of Special Plant Germplasm in Wuling Area of China, College of Life Sciences, South-Central Minzu University, Wuhan, 430070, China.
| | - Cong Yin
- Hubei Provincial Key Laboratory for Protection and Application of Special Plant Germplasm in Wuling Area of China, College of Life Sciences, South-Central Minzu University, Wuhan, 430070, China.
| | - Hong Liu
- Hubei Provincial Key Laboratory for Protection and Application of Special Plant Germplasm in Wuling Area of China, College of Life Sciences, South-Central Minzu University, Wuhan, 430070, China.
| | - Rui Qin
- Hubei Provincial Key Laboratory for Protection and Application of Special Plant Germplasm in Wuling Area of China, College of Life Sciences, South-Central Minzu University, Wuhan, 430070, China.
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Adibnia V, Ma Y, Halimi I, Walker GC, Banquy X, Kumacheva E. Phytoglycogen Nanoparticles: Nature-Derived Superlubricants. ACS NANO 2021; 15:8953-8964. [PMID: 33960783 DOI: 10.1021/acsnano.1c01755] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Phytoglycogen nanoparticles (PhG NPs), a single-molecule highly branched polysaccharide, exhibit excellent water retention, due to the abundance of close-packed hydroxyl groups forming hydrogen bonds with water. Here we report lubrication properties of close-packed adsorbed monolayers of PhG NPs acting as boundary lubricants. Using direct surface force measurements, we show that the hydrated nature of the NP layer results in its striking lubrication performance, with two distinct confinement-controlled friction coefficients. In the weak- to moderate-confinement regime, when the NP layer is compressed down to 8% of its original thickness under a normal pressure of up to 2.4 MPa, the NPs lubricate the surface with a friction coefficient of 10-3. In the strong-confinement regime, with 6.5% of the original layer thickness under a normal pressure of up to 8.1 MPa, the friction coefficient was 10-2. Analysis of the water content and energy dissipation in the confined NP film reveals that the lubrication is governed by synergistic contributions of unbound and bound water molecules, with the former contributing to lubrication properties in the weak- to moderate-confinement regime and the latter being responsible for the lubrication in the strong-confinement regime. These results unravel mechanistic insights that are essential for the design of lubricating systems based on strongly hydrated NPs.
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Affiliation(s)
- Vahid Adibnia
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada, M5S 3H6
- Faculty of Pharmacy, Université de Montréal, Montreal, Quebec, Canada, H3C 3J7
| | - Yingshan Ma
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada, M5S 3H6
| | - Ilias Halimi
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada, M5S 3H6
| | - Gilbert C Walker
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada, M5S 3H6
| | - Xavier Banquy
- Faculty of Pharmacy, Université de Montréal, Montreal, Quebec, Canada, H3C 3J7
| | - Eugenia Kumacheva
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada, M5S 3H6
- Institute of Biomedical Engineering, University of Toronto, Toronto, Canada, M5S 3G9
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Canada, M5S 3E5
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Wang Q, Hou T, Wang W, Zhang G, Gao Y, Wang K. Tribological properties of black phosphorus nanosheets as oil-based lubricant additives for titanium alloy-steel contacts. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200530. [PMID: 33047021 PMCID: PMC7540757 DOI: 10.1098/rsos.200530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 07/30/2020] [Indexed: 06/11/2023]
Abstract
The black phosphorus (BP) powders were prepared by high-energy ball milling with red phosphorus as the raw material, and then the BP nanosheets were obtained by liquid-phase exfoliation. The tribological properties of the BP nanosheets as oil-based lubricant additives were investigated by the ball-on-disc tribometer. Results show that compared with the base oil of liquid paraffin (LP), the coefficient of friction and wear rate of the BP nanosheets as the additives in liquid paraffin (BP-LP) are lower for the same loads. BP-LP lubricants could significantly improve the load-bearing capacity of the base oil for titanium alloy-steel contacts and show excellent friction-reducing and anti-wear properties. The surface morphologies and elemental compositions of the friction pairs were further analysed using an optional microscope, scanning electron microscope and X-ray photoelectron spectroscopy. The lubrication mechanism of BP-LP can be attributed to the synergistic effects between lamellar adsorption and interlayer shear of BP nanosheets.
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Affiliation(s)
- Qingjuan Wang
- School of Metallurgy Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Tingli Hou
- School of Metallurgy Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Wei Wang
- School of Metallurgy Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Guoliang Zhang
- School of Mechanical Engineering, Tianjin University of Technology and Education, Tianjin 300222, People's Republic of China
- Guangdong Provincial Key Lab of Nano-Micro Materials Research, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, People's Republic of China
| | - Yuan Gao
- School of Metallurgy Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Kuaishe Wang
- School of Metallurgy Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
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Jia W, Bai P, Zhang W, Ma L, Meng Y, Tian Y. On Lubrication States after a Running-In Process in Aqueous Lubrication. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:15435-15443. [PMID: 31125241 DOI: 10.1021/acs.langmuir.9b01105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Recently, many studies have reported the ultralow friction coefficient of sliding friction between rigid solid surfaces in aqueous lubrication. A running-in process that goes through high-friction and friction-decreasing regions to a stable ultralow friction region is often required. However, the role of the friction-decreasing region is often ascribed to tribofilm formation in which complexity hindered the quantitative description of the running-in process and the prediction of its subsequent lubrication state. In this work, the frictional energy (Ef) dissipated in the running-in process of a poly(oligo(ethylene glycol) methyl ether acrylate) aqueous lubrication was related to the wear of solid surfaces under different conditions and lubrication states. Experimental results indicated that the high-friction region was in a boundary lubrication state, contributed to most of the wear, and significantly reduced the contact pressure, whereas the friction-decreasing region was in a mixed lubrication state, contributed only to the slight and slow removal of materials, and slightly reduced the contact pressure. Therefore, by establishing relationships among the wear scar diameter, Ef, and the Stribeck curve of the tribological system, the subsequent lubrication state after a running-in process under various working loads and sliding speeds could be quantitatively predicted. The running-in experiments with different aqueous lubrication systems showed good agreement with the prediction of this method. This investigation provides an effective method for the wear and lubrication state prediction after a running-in process, further proving the importance of the Stribeck curve for a lubrication system. This study may also have important implications for the strategy design of the running-in process in various industrial applications.
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Affiliation(s)
- Wenpeng Jia
- State Key Laboratory of Tribology, Department of Mechanical Engineering , Tsinghua University , Beijing 100084 , China
| | - Pengpeng Bai
- State Key Laboratory of Tribology, Department of Mechanical Engineering , Tsinghua University , Beijing 100084 , China
| | - Wenling Zhang
- Department of Chemical and Materials Engineering , University of Alberta , Edmonton , Alberta T6G 1H9 , Canada
| | - Liran Ma
- State Key Laboratory of Tribology, Department of Mechanical Engineering , Tsinghua University , Beijing 100084 , China
| | - Yonggang Meng
- State Key Laboratory of Tribology, Department of Mechanical Engineering , Tsinghua University , Beijing 100084 , China
| | - Yu Tian
- State Key Laboratory of Tribology, Department of Mechanical Engineering , Tsinghua University , Beijing 100084 , China
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Yang C, Zhang X, Zhang F, Wang X, Wang Q. Structure and ion physiology of Brasenia schreberi glandular trichomes in vivo. PeerJ 2019; 7:e7288. [PMID: 31637113 PMCID: PMC6802583 DOI: 10.7717/peerj.7288] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 06/11/2019] [Indexed: 12/04/2022] Open
Abstract
Brasenia schreberi is a critically endangered aquatic basal angiosperm. In this work, we characterized the structure of the glandular trichomes of B. schreberi morphologically and histochemically. We used a variety of structural, histochemical and permeability stains for the characterization, and we tested the effects of stress in vivo using NaCl and ethanol. We observed that the glandular trichome of B. schreberi are composed of two disk-like stalk cells, and a glandular cell which surround a cuticular storage space. The cuticle is discontinuous at the surface of the shoots. Nearly half of young trichomes senesced in 0.9% NaCl, and mature trichomes senesced at 1.8% NaCl. About half of young trichomes senesced under 3% ethanol and mature trichomes senesced in 2% ethanol after 20 min of treatment. The physiology of glandular trichomes affects the way they secrete mucilage via storage space at a young stage. The trichomes become permeable and absorb ions when mature. This transition depends on the osmiophilic material and the dynamic protoplast. It can accelerate senescence and disassembly by ion accumulation. Permeability tests and ion treatments of glandular trichomes provide new insights for fertilizer research. Our study highlights the structure and physiology of B. schreberi glandular trichomes.
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Affiliation(s)
- Chaodong Yang
- The School of Horticulture and Gardening, Yangtze University, JIngzhou, Hubei, China
| | - Xia Zhang
- The School of Horticulture and Gardening, Yangtze University, JIngzhou, Hubei, China
| | - Fan Zhang
- The School of Horticulture and Gardening, Yangtze University, JIngzhou, Hubei, China
| | - Xiaoe Wang
- The School of Horticulture and Gardening, Yangtze University, JIngzhou, Hubei, China
| | - Qingfeng Wang
- Wuhan Botanical Garden, The Chinese Academy of Sciences, Wuhan, China
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Liu W, Wang H, Liu Y, Li J, Erdemir A, Luo J. Mechanism of Superlubricity Conversion with Polyalkylene Glycol Aqueous Solutions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:11784-11790. [PMID: 31432683 DOI: 10.1021/acs.langmuir.9b01857] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In this study, ultralow friction coefficient (COF, μ < 0.01) was obtained through polyalkylene glycol (PAG) aqueous solutions with different molecular weights (MWs) ranging from 270 to 3930 g·mol-1 under ambient conditions. With the increase in the MWs of PAG molecules, the threshold concentration to obtain this type of superlubric behavior gradually changed from 90 to 60 wt %. This phenomenon was closely related to the interaction between PAG chains and water molecules and the state of chemical binding. In the superlubricity system, superior load-bearing capacity was achieved at optimal threshold concentrations of all PAG aqueous solutions wherein multilayered adsorption layers that consisted of fully hydrated PAG molecules were formed on the sliding solid surfaces. With respect to the concentration below the threshold value, the existence of a shearing layer was indicated to play a significant role. Thus, the synergetic effect of sufficient adsorption of molecules and the unique shear rheology of the PAG aqueous solution were essential to achieve superlubricity.
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Affiliation(s)
- Wenrui Liu
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
| | - Hongdong Wang
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
- Energy Systems Division , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - Yuhong Liu
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
| | - Jinjin Li
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
| | - Ali Erdemir
- Energy Systems Division , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - Jianbin Luo
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
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Feng S, Ning K, Luan D, Lu S, Sun P. Chemical composition and antioxidant capacities analysis of different parts of
Brasenia schreberi. J FOOD PROCESS PRES 2019. [DOI: 10.1111/jfpp.14014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Simin Feng
- Department of Food Science and Engineering Zhejiang University of Technology Hangzhou People's Republic of China
| | - Ke Ning
- Department of Food Science and Engineering Zhejiang University of Technology Hangzhou People's Republic of China
| | - Di Luan
- Department of Food Science and Engineering Zhejiang University of Technology Hangzhou People's Republic of China
| | - Shengmin Lu
- Institute of Food Science Zhejiang Academy of Agricultural Sciences Hangzhou People's Republic of China
| | - Peilong Sun
- Department of Food Science and Engineering Zhejiang University of Technology Hangzhou People's Republic of China
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Feng S, Luan D, Ning K, Shao P, Sun P. Ultrafiltration isolation, hypoglycemic activity analysis and structural characterization of polysaccharides from Brasenia schreberi. Int J Biol Macromol 2019; 135:141-151. [DOI: 10.1016/j.ijbiomac.2019.05.129] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/18/2019] [Accepted: 05/20/2019] [Indexed: 12/15/2022]
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Wang H, Liu Y, Liu W, Liu Y, Wang K, Li J, Ma T, Eryilmaz OL, Shi Y, Erdemir A, Luo J. Superlubricity of Polyalkylene Glycol Aqueous Solutions Enabled by Ultrathin Layered Double Hydroxide Nanosheets. ACS APPLIED MATERIALS & INTERFACES 2019; 11:20249-20256. [PMID: 31083968 DOI: 10.1021/acsami.9b03014] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
It was previously proved that the existence of a large amount of hydrogen ions in water-based lubricants can easily lead to a superlubric state; however, it was also shown that these hydrogen ions could cause severe corrosion. As part of a large family of attractive clays, layered double hydroxides (LDHs) possess excellent tribological properties in water-based lubrication systems. In the present work, two different kinds of LDHs are dispersed in polyalkylene glycol (PAG) aqueous solutions, in two distinct forms: ultrathin nanosheets (ULDH-NS) of ca. 60 nm wide and ca. 1 nm thick (single or double layer) and nanoparticles (LDH-NP) of ca. 19.73 nm wide and ca. 8.68 nm thick. We find that the addition of ULDH-NS greatly shortens (as much as 85%) the running-in period prior to reaching the superlubricity regime and increases the ultimate load-bearing capacity by about four times. As compared to the fluid film thickness of the lubricating PAG solution, their ultrathin longitudinal dimension will not impair or influence the fluid film coverage in the contact zone. The analysis of sliding solid surfaces and the atomic force microscope microscale friction test demonstrate that the adsorption of ULDH-NS enables the sliding solid surfaces to be polished and protected because of their relatively weak interlayer interaction and increased adhesion effect. Owing to their superior tribological properties as lubricant additives, ultrathin LDH nanosheets hold great potential for enabling liquid superlubricity in industrial applications in the future.
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Affiliation(s)
- Hongdong Wang
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
- Applied Materials Division , Argonne National Laboratory , Argonne , Illinois 60439 , United States
- Division of Machine Elements , Luleå University of Technology , Luleå 97187 , Sweden
| | - Yuhong Liu
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
| | - Wenrui Liu
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
| | - Yanmin Liu
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
| | - Kunpeng Wang
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
| | - Jinjin Li
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
| | - Tianbao Ma
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
| | - Osman Levent Eryilmaz
- Applied Materials Division , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - Yijun Shi
- Division of Machine Elements , Luleå University of Technology , Luleå 97187 , Sweden
| | - Ali Erdemir
- Applied Materials Division , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - Jianbin Luo
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
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Optimizing the Extraction and Encapsulation of Mucilage from Brasenia Schreberi. Polymers (Basel) 2019; 11:polym11050822. [PMID: 31067742 PMCID: PMC6571674 DOI: 10.3390/polym11050822] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/20/2019] [Accepted: 04/28/2019] [Indexed: 12/31/2022] Open
Abstract
The mucilage from Brasenia schreberi (BS) exhibits various biological activities, including antialgal, antibacterial, soluble-fiber properties, and excellent lubricating behavior. Thus, the extraction and wide use of mucilage in the food industry are crucial. In this study, the high-speed shear-assisted extraction of mucilage from BS was optimized by using response surface methodology (RSM). The optimal extraction conditions were as follows: Extraction temperature of 82 °C, extraction time of 113 min, liquid–solid ratio of 47 mL/g, and shear speed of 10,000 rpm. Under these conditions, the actual yield of BS mucilage was 71.67%, which highly matched the yield (73.44%) predicted by the regression model. Then, the BS mucilage extract was powdered to prepare the capsule, and the excipients of the capsule were screened using a single-factor test to improve the disintegration property and flowability. The final capsule formulation, which consisted of: 39% BS mucilage powder (60 meshes); 50% microcrystalline cellulose (60 meshes) as the filler; both 10% sodium starch glycolate and PVPP XL-10 (3:1, 60 meshes) as the disintegrant; both 1% colloidal silicon dioxide and sodium stearyl fumarate (1:1, 100 meshes) as the glidant by weight; were used for preparing the weights of a 320 mg/grain of capsule with 154.7 ± 0.95 mg/g polysaccharide content. Overall, the optimized extraction process had a high extraction rate for BS mucilage and the capsule formulation was designed reasonably.
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Jia W, Tian J, Bai P, Li S, Zeng H, Zhang W, Tian Y. A novel comb-typed poly(oligo(ethylene glycol) methylether acrylate) as an excellent aqueous lubricant. J Colloid Interface Sci 2018; 539:342-350. [PMID: 30594009 DOI: 10.1016/j.jcis.2018.12.085] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 12/22/2018] [Accepted: 12/22/2018] [Indexed: 11/16/2022]
Abstract
HYPOTHESIS Aqueous lubricants exhibit versatile advantages over oil-based lubricants. However, it still remains a challenge for the aqueous solutions to obtain excellent lubrication properties with high contact pressure on macroscale. EXPERIMENTS In this work, a comb-typed poly(oligo(ethylene glycol) methylether acrylate) (P(OEGMA)) was successfully synthesized via RAFT polymerization. Rheological, morphological and tribological properties of prepared P(OEGMA) aqueous solutions were characterized via a rheometer, cryo-SEM and ball-on-disk tribometer, respectively. FINDINGS The synthesized P(OEGMA) exhibited a uniformly smaller size than that of the commercial linear polyethylene glycol (PEG), leading to reduced viscosities in aqueous solutions. The obtained P(OEGMA) aqueous solutions achieved outstandingly ultralow friction coefficients (μ < 0.01) and a good wear-resistance under high pressure (>300 MPa, two-fold increase than reported in the previous literature). The desirable lubricating performances can be attributed to the well-established running-in period, a good interfacial adsorption property between polymer molecules and solid surfaces, the hydration effect as well as the hydrodynamic effect. The current finding reveals the excellent aqueous lubrication properties possessed by the synthesized comb-typed P(OEGMA), which can broaden the development of aqueous lubricants in practical engineering fields.
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Affiliation(s)
- Wenpeng Jia
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Jinmi Tian
- College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Pengpeng Bai
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Shaowei Li
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Hongbo Zeng
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Wenling Zhang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.
| | - Yu Tian
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China.
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Environmental factors influencing mucilage accumulation of the endangered Brasenia schreberi in China. Sci Rep 2018; 8:17955. [PMID: 30560901 PMCID: PMC6298988 DOI: 10.1038/s41598-018-36448-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 11/21/2018] [Indexed: 01/06/2023] Open
Abstract
Brasenia schreberi J. F. Gmel. (Cabombaceae), a perennial freshwater macrophyte characterized by a thick mucilage on all underwater organs and especially young buds, has been widely cultivated as an aquatic vegetable in China for many years but is now listed as an endangered species due to anthropogenic impacts and habitat loss. Recent studies have demonstrated that different B. schreberi populations in China have low levels of genetic diversity but significantly different mucilage contents (MucC). Considering the importance of mucilage on both economic and ecological aspects, we examined mucilage-environment relationships in three B. schreberi cultivation sites. The results indicated that water permanganate index (CODMn), total N (TNw), electrical conductivity (ECw), dissolved oxygen (DOw), sediment organic carbon (SOC) and total N (TNs) were significant factors, which explained 82.2% of the variation in mucilage accumulation. The MucC and mucilage thickness (MucT) as well as single bud weight (SBW) of B. schreberi showed negative relationships with CODMn, TNw and ECw but positive relationships with SOC and TNs. Besides, high temperature may have a negative impact on mucilage accumulation of the species. Our study demonstrated that the mucilage accumulation of B. schreberi required good water quality and nutrient-enriched sediments, suggesting that habitat conservation, especially the quality of water, is important for maintaining B. schreberi populations.
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Shi H, Liu Y, Zeng Q, Yang Y, Wang C, Lu X. Interfacial assembly structures and nanotribological properties of saccharic acids. Phys Chem Chem Phys 2017; 19:1236-1243. [DOI: 10.1039/c6cp06759j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The larger friction of the successfully constructed assembly of saccharic acid indicates the higher potential energy barrier at the interface.
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Affiliation(s)
- Hongyu Shi
- State Key Laboratory of Tribology
- Tsinghua University
- Beijing 100084
- China
| | - Yuhong Liu
- State Key Laboratory of Tribology
- Tsinghua University
- Beijing 100084
- China
| | - Qingdao Zeng
- National Center for Nanoscience and Technology
- Beijing 100190
- China
| | - Yanlian Yang
- National Center for Nanoscience and Technology
- Beijing 100190
- China
| | - Chen Wang
- National Center for Nanoscience and Technology
- Beijing 100190
- China
| | - Xinchun Lu
- State Key Laboratory of Tribology
- Tsinghua University
- Beijing 100084
- China
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15
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Xiao C, Li J, Chen L, Zhang C, Zhou N, Qian L, Luo J. Speed dependence of liquid superlubricity stability with H3PO4 solution. RSC Adv 2017. [DOI: 10.1039/c7ra09217b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The water-based superlubricity can be promoted to a high-speed of 1.6 m s−1 after pre-running-in at low-speed of 0.075 m s−1.
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Affiliation(s)
- Chen Xiao
- Tribology Research Institute
- State Key Laboratory of Traction Power
- Southwest Jiaotong University
- Chengdu 610031
- China
| | - Jinjin Li
- State Key Laboratory of Tribology
- Tsinghua University
- Beijing 100084
- China
| | - Lei Chen
- Tribology Research Institute
- State Key Laboratory of Traction Power
- Southwest Jiaotong University
- Chengdu 610031
- China
| | - Chenhui Zhang
- State Key Laboratory of Tribology
- Tsinghua University
- Beijing 100084
- China
| | - Ningning Zhou
- Beijing Key Laboratory of Long-life Technology of Precise Rotation and Transmission Mechanisms
- Beijing Institute of Control Engineering
- Beijing 100094
- China
| | - Linmao Qian
- Tribology Research Institute
- State Key Laboratory of Traction Power
- Southwest Jiaotong University
- Chengdu 610031
- China
| | - Jianbin Luo
- State Key Laboratory of Tribology
- Tsinghua University
- Beijing 100084
- China
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Slippery when sticky: Lubricating properties of thin films of Taxus baccata aril mucilage. Biointerphases 2016; 11:011010. [PMID: 26903309 DOI: 10.1116/1.4942208] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Mucilage is hydrogel produced from succulent plants and microorganisms displaying unique adhesiveness and slipperiness simultaneously. The objective of this study is to establish an understanding on the lubricating mechanisms of the mucilage from Taxus baccata aril as thin, viscous lubricant films. Oscillation and flow rheological studies revealed that T. baccata mucilage is shear-thinning, thixotropic, and weak hydrogel that is highly stretchable under shear stress due to its high density physical crosslinking characteristics. In addition, T. baccata mucilage showed a distinct Weissenberg effect, i.e., increasing normal force with increasing shear rate, and thus it contributes to deplete the lubricant from tribological interfaces. Lubrication studies with a number of tribopairs with varying mechanical properties and surface wettability have shown that the lubricity of T. baccata mucilage is most effectively manifested at soft, hydrophilic, and rolling tribological contacts. Based on tenacious spreading on highly wetting surfaces, slip plane can be formed within mucilage hydrogel network even when the lubricating films cannot completely separate the opposing surfaces. Moreover, highly stretchable characteristics of mucilage under high shear enhance smooth shearing of two opposing surfaces as lubricating film.
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Wang H, Liu Y, Chen Z, Wu B, Xu S, Luo J. Layered Double Hydroxide Nanoplatelets with Excellent Tribological Properties under High Contact Pressure as Water-Based Lubricant Additives. Sci Rep 2016; 6:22748. [PMID: 26951794 PMCID: PMC4782130 DOI: 10.1038/srep22748] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 02/19/2016] [Indexed: 11/09/2022] Open
Abstract
High efficient and sustainable utilization of water-based lubricant is essential for saving energy. In this paper, a kind of layered double hydroxide (LDH) nanoplatelets is synthesized and well dispersed in water due to the surface modification with oleylamine. The excellent tribological properties of the oleylamine-modified Ni-Al LDH (NiAl-LDH/OAm) nanoplatelets as water-based lubricant additives are evaluated by the tribological tests in an aqueous environment. The modified LDH nanoplatelets are found to not only reduce the friction but also enhance the wear resistance, compared with the water-based cutting fluid and lubricants containing other particle additives. By adding 0.5 wt% LDH nanoplatelets, under 1.5 GPa initial contact pressure, the friction coefficient, scar diameter, depth and width of the wear track dramatically decrease by 83.1%, 43.2%, 88.5% and 59.5%, respectively. It is considered that the sufficiently small size and the excellent dispersion of NiAl-LDH/OAm nanoplatelets in water are the key factors, so as to make them enter the contact area, form a lubricating film and prevent direct collision of asperity peaks. Our investigations demonstrate that the LDH nanoplatelet as a water-based lubricant additive has a great potential value in industrial application.
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Affiliation(s)
- Hongdong Wang
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Yuhong Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Zhe Chen
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Bibo Wu
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Sailong Xu
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Jianbin Luo
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
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