1
|
Yu H, Zhang S, Wang Z, Li A, Sun X, Niu L, Li Q. Construction and modulation of dual responsive AIE supramolecular aggregates combined with quantum chemistry simulation. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
2
|
D. Alharthy R, El-Nagar RA, Ghanem A. Laboratory Experiments on the In Situ Upgrading of Heavy Crude Oil Using Catalytic Aquathermolysis by Acidic Ionic Liquid. MATERIALS (BASEL, SWITZERLAND) 2022; 15:5959. [PMID: 36079342 PMCID: PMC9457198 DOI: 10.3390/ma15175959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/19/2022] [Accepted: 08/22/2022] [Indexed: 06/15/2023]
Abstract
Heavy and extra heavy oil exploitation has attracted attention in the last few years because of the decline in the production of conventional crude oil. The high viscosity of heavy crude oil is the main challenge that obstructs its extraction. Consequently, catalytic aquathermolysis may be an effective solution to upgrade heavy crude oil to decrease its viscosity in reservoir conditions. In this regard, a series of acidic ionic liquids, 1-butyl-1H-imidazol-3-ium 4-dodecylbenzenesulfonate (IL-4), 1-decyl-1H-imidazol-3-ium 4-dodecylbenzenesulfonate (IL-10), and 1-hexadecyl-1H-imidazol-3-ium 4-dodecylbenzenesulfonate (IL-16), were utilized in the aquathermolysis of heavy crude oil. Of each IL, 0.09 wt % reduced the viscosity of the crude oil by 89%, 93.7%, and 94.3%, respectively, after the addition of 30% water at 175 °C. ILs with alkyl chains equal to 10 carbon atoms or more displayed greater activity in viscosity reduction than that of ILs with alkyl chains lower than 10 carbon atoms. The molecular weight and asphaltene content of the crude oil were decreased after catalytic aquathermolysis. The compositional analysis of the crude oil before and after catalytic aquathermolysis showed that the molar percentage of lighter molecules from tridecanes to isosanes was increased by 26-45%, while heavier molecules such as heptatriacontanes, octatriacontanes, nonatriacontanes, and tetracontanes disappeared. The rheological behavior of the crude oil before and after the catalytic aquathermolytic process was studied, and the viscosity of the crude oil sample was reduced strongly from 678, 29.7, and 23.4 cp to 71.8, 16.9, and 2.7 cp at 25, 50, and 75 °C, respectively. The used ILs upgraded the heavy crude oil at a relatively low temperature.
Collapse
Affiliation(s)
- Rima D. Alharthy
- Department of Chemistry, Science and Arts College, Rabigh Branch, King Abdulaziz University, Rabigh 21911, Saudi Arabia
| | - Raghda A. El-Nagar
- Oil Lab Analysis, Analysis and Evaluation Department, Egyptian Petroleum Research Institute, Nasr City, Cairo 11727, Egypt
| | - Alaa Ghanem
- PVT-Lab, Production Department, Egyptian Petroleum Research Institute, Nasr City, Cairo 11727, Egypt
- PVT Services Center, Egyptian Petroleum Research Institute, Nasr City, Cairo 11727, Egypt
| |
Collapse
|
3
|
Patel N, Soni SS, Patel N, Patel K, Patel VK, Sharma D, Panjabi SH. Synthesis, Self-Aggregation, Surface Characteristics, Electrochemical Property, Micelle Size, and Antimicrobial Activity of a Halogen-Free Picoline-Based Surface-Active Ionic Liquid. ACS OMEGA 2022; 7:28974-28984. [PMID: 36033664 PMCID: PMC9404176 DOI: 10.1021/acsomega.2c02612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
We present a new approach toward the design of a halogen-free picoline-based surface-active ionic liquid (SAIL) (1-octyl-4-methyl pyridinium dodecyl sulfate) [C8γPic]DS consisting of long dodecyl sulfate (DS) as an anion. The surface properties, micellization behavior, and antimicrobial activity in an aqueous solution were investigated using tensiometry, conductometry, and ultraviolet (UV) spectroscopy. Incorporating the DS group in SAIL leads to lower critical micellar concentration (CMC) and enhanced adsorption at the air/water interface of the functionalized ionic liquid compared to the C8-alkyl chain-substituted pyridine ionic liquids. The antimicrobial activity was evaluated against a representative Gram-negative and Gram-positive bacteria panel. Antibacterial activities increased with the alkyl chain length, C8 being the homologous most effective antimicrobial agent. The micelle size of [C8γPic]DS was determined by the dynamic light-scattering (DLS) study. Cyclic voltammetry (CV) measurements have been employed to evaluate the interaction between the SAIL micelle and working electrode, diffusion coefficient, and micelle size of the SAIL solution. The diffusion coefficient explored the correlation of surface properties and the antimicrobial activity of [C8γPic]DS. This halogen-free SAIL is the future of wetting agents and emulsion studies in agriculture due to its small micelle size and surface characteristics.
Collapse
Affiliation(s)
- Nidhi
N. Patel
- Department
of Chemical Sciences, P. D. Patel Institute of Applied Sciences, CHARUSAT University, Changa, Gujarat 388421, India
| | - Saurabh S. Soni
- Department
of Chemistry, Sardar Patel University, Vallabh Vidyanagar, Anand, Gujarat388120, India
| | - Niraj Patel
- Organic
Chemistry Department, Institute of Science and Technology for Advanced
Research (ISTAR), CVM University, Vallabh Vidyanagar, Anand, Gujarat 388120, India
| | - Kiran Patel
- Director,
Grow Leaf Biotech Private Limited, Anand, Gujarat 388120, India
| | - Vaibhav K. Patel
- Department
of Chemical Sciences, P. D. Patel Institute of Applied Sciences, CHARUSAT University, Changa, Gujarat 388421, India
| | - Deep Sharma
- Department
of Chemical Sciences, P. D. Patel Institute of Applied Sciences, CHARUSAT University, Changa, Gujarat 388421, India
| | - Sanjay H. Panjabi
- Department
of Chemical Sciences, P. D. Patel Institute of Applied Sciences, CHARUSAT University, Changa, Gujarat 388421, India
| |
Collapse
|
4
|
Kaur R, Kumar H, Kumar B, Singla M, Kumar V, Ghfar AA, Pandey S. Effect of amino acid on the surface adsorption and micellar properties of surface active ILs varying in cationic head groups. Heliyon 2022; 8:e10363. [PMID: 36082336 PMCID: PMC9445298 DOI: 10.1016/j.heliyon.2022.e10363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/19/2022] [Accepted: 08/15/2022] [Indexed: 11/25/2022] Open
Abstract
The interfacial along with bulk characteristics of the aqueous solutions of ILs with dissimilar cationic head group viz. 1-dodecyl-3-methylimidazolium bromide ([C12mim][Br]), and N-dodecyl-N-methylmorpholinium bromide ([Mor1,12][Br]) in the absence and the presence of an amino acid L-Methionine as an external additive have been examined by electrical conductivity, UV-Visible, surface tension, and DLS measurements. The CMC values, and the lowest maximum surface excess concentration (Гmax) achieved from all three techniques, and surface tension measurements respectively displayed more surface activity of the [C12mim][Br] than the [Mor1,12][Br]. Also, the morpholinium head group is less hazardous than imidazolium, it can be utilised to design ILs that are greener, mainly in combination with polar, small, and non-toxic side chains and anions.
Collapse
|
5
|
Fu D, Gao X, Wang J, Jiang H, Zheng M, Li P, Huang B, Kan K, Zhang X. Micellization and thermodynamics study of ester functionalized picoline-based ionic liquid surfactants in water. RSC Adv 2022; 12:14477-14484. [PMID: 35702243 PMCID: PMC9097595 DOI: 10.1039/d2ra01706g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 04/29/2022] [Indexed: 11/21/2022] Open
Abstract
A novel series of picoline-based ionic liquid surfactants, N-alkyoxycarbonyl-3-picoline bromides [C n Empy][Br] (n = 10, 12, 14), have been synthesized. The thermal stability, aggregation behavior and surface activity of the synthetic ionic liquid surfactants were investigated systematically though a series of methods, such as thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), tensiometry and conductivity. The thermodynamics of micellization of the ionic liquid surfactants solution were studied by using the conductivity method in the temperature range 278.15-318.15 K. The surface activity parameters and thermodynamics parameters were derived, respectively. The enthalpy-entropy compensation effect was further discussed by using relative thermodynamics parameters. It was found that the [C n Empy][Br] have moderate surface activity, and their critical micelle concentration (CMC) decreased with the ester-functionalized chain length and exhibited a U-shape with temperature. The calculation results of the thermodynamic parameters showed that the micellization processes of [C n Empy][Br] were spontaneous, endothermic at low temperature and exothermic at higher temperature.
Collapse
Affiliation(s)
- Dong Fu
- Heilongjiang Academy of Sciences, Institute of Advanced Technology Harbin P. R. China .,College of Materials Science and Chemical Engineering, Harbin Engineering University Harbin P. R. China
| | - Xiaoru Gao
- Harbin Fiber Reinforced Plastic Institute Harbin P. R. China
| | - Jue Wang
- Heilongjiang Academy of Sciences, Institute of Advanced Technology Harbin P. R. China
| | - Haijian Jiang
- Heilongjiang Academy of Sciences, Institute of Advanced Technology Harbin P. R. China
| | - Mingming Zheng
- Heilongjiang Academy of Sciences, Institute of Advanced Technology Harbin P. R. China
| | - Peng Li
- Heilongjiang Academy of Sciences, Institute of Advanced Technology Harbin P. R. China
| | - Bo Huang
- Heilongjiang Academy of Sciences, Institute of Advanced Technology Harbin P. R. China
| | - Kan Kan
- Heilongjiang Academy of Sciences, Institute of Advanced Technology Harbin P. R. China
| | - Xiaochen Zhang
- Heilongjiang Academy of Sciences, Institute of Advanced Technology Harbin P. R. China
| |
Collapse
|
6
|
Pillai P, Mandal A. Synthesis and characterization of surface-active ionic liquids for their potential application in enhanced oil recovery. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2021.117900] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
7
|
|
8
|
Importance of structures and interactions in ionic liquid-nanomaterial composite systems as a novel approach for their utilization in safe lithium metal batteries: A review. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116736] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
9
|
Sastry NV, Trivedi PA. Drug anion based surface active ionic liquids: Molecular interactions, surface activity and micellization behavior in aqueous solutions. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
10
|
Fu D, Gao X, Wang J, Xie Y, Yang F, Sui X, Li P, Huang B, Zhang X, Kan K. Micellization, surface activities and thermodynamics study of dialkylpyridinium [C16pymCn][Br] (n = 1–4) in aqueous solutions. J DISPER SCI TECHNOL 2020. [DOI: 10.1080/01932691.2019.1710528] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Dong Fu
- Institute of Advanced Technology, Heilongjiang Academy of Sciences, Harbin, People’s Republic of China
| | - Xiaoru Gao
- Harbin FRP Research Institute, Harbin, People’s Republic of China
| | - Jue Wang
- Institute of Advanced Technology, Heilongjiang Academy of Sciences, Harbin, People’s Republic of China
| | - Yang Xie
- Institute of Advanced Technology, Heilongjiang Academy of Sciences, Harbin, People’s Republic of China
| | - Fan Yang
- Institute of Advanced Technology, Heilongjiang Academy of Sciences, Harbin, People’s Republic of China
| | - Xin Sui
- Institute of Advanced Technology, Heilongjiang Academy of Sciences, Harbin, People’s Republic of China
| | - Peng Li
- Institute of Advanced Technology, Heilongjiang Academy of Sciences, Harbin, People’s Republic of China
| | - Bo Huang
- Institute of Advanced Technology, Heilongjiang Academy of Sciences, Harbin, People’s Republic of China
| | - Xiaochen Zhang
- Institute of Advanced Technology, Heilongjiang Academy of Sciences, Harbin, People’s Republic of China
| | - Kan Kan
- Institute of Advanced Technology, Heilongjiang Academy of Sciences, Harbin, People’s Republic of China
| |
Collapse
|
11
|
Mezzetta A, Łuczak J, Woch J, Chiappe C, Nowicki J, Guazzelli L. Surface active fatty acid ILs: Influence of the hydrophobic tail and/or the imidazolium hydroxyl functionalization on aggregates formation. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111155] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
12
|
Tariq S, Rahim A, Muhammad N, Rahman SU, Azhar U, Sultana K, Sharif F, Siddiqi SA, Zaman M, Rehman F. Controllable delivery from gentamicin loaded polycaprolactone/grafted silica nanoparticles composite mats. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111205] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
|
13
|
Application of surface-active ionic liquids in micelle-mediated extraction methods: pre-concentration of cadmium ions by surface-active ionic liquid-assisted cloud point extraction. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2019. [DOI: 10.1007/s13738-019-01770-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
14
|
Li Q, Tong K, Qiu J, Yan M, Tian Q, Chen X, Yue X. Molecular packing of surface active ionic liquids in a deep eutectic solvent: a small angle X-ray scattering (SAXS) study. SOFT MATTER 2019; 15:5060-5066. [PMID: 31180406 DOI: 10.1039/c9sm00760a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
During the past decade, deep eutectic solvents (DESs) have shown promising application in the self-assembly of surfactants. Various aggregates such as micelles, vesicles, lyotropic liquid crystals, microemulsions and gels have been reported. In this research, the phase behaviours of imidazolium surface active ionic liquids (SAILs) CnmimBr (n = 12, 14, 16) were investigated in ChG. With the help of small angle X-ray scattering (SAXS), the types and structure parameters of aggregates were determined. The molecular packing of SAILs was influenced by the solvophobic chain length, surfactant concentration, temperature and solvent, accounting for their different aggregation behaviours. This study would give a good description of the molecular packing of surfactants in DESs.
Collapse
Affiliation(s)
- Qintang Li
- State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621000, China.
| | | | | | | | | | | | | |
Collapse
|
15
|
Yang X, Zhang P, Lv W, Zhou T, Li P, Zhao M. Aggregation Behavior of Imidazolium‐Based Amino Acid Ionic Liquid Surfactants in Aqueous Solution: The Effect of Amino Acid Counterions. J SURFACTANTS DETERG 2019. [DOI: 10.1002/jsde.12270] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Xiu‐Jie Yang
- State Key Laboratory of Heavy Oil ProcessingChina University of Petroleum (East China) 66 Changjiang West Road, Qingdao, 266580 China
| | - Peng Zhang
- State Key Laboratory of Heavy Oil ProcessingChina University of Petroleum (East China) 66 Changjiang West Road, Qingdao, 266580 China
| | - Wenjiao Lv
- State Key Laboratory of Heavy Oil ProcessingChina University of Petroleum (East China) 66 Changjiang West Road, Qingdao, 266580 China
| | - Ting Zhou
- State Key Laboratory of Heavy Oil ProcessingChina University of Petroleum (East China) 66 Changjiang West Road, Qingdao, 266580 China
| | - Peng Li
- State Key Laboratory of Heavy Oil ProcessingChina University of Petroleum (East China) 66 Changjiang West Road, Qingdao, 266580 China
| | - Mingwei Zhao
- State Key Laboratory of Heavy Oil ProcessingChina University of Petroleum (East China) 66 Changjiang West Road, Qingdao, 266580 China
| |
Collapse
|
16
|
Zhu H, Vijayaraghavan R, MacFarlane DR, Forsyth M. Self-assembled structure and dynamics of imidazolium-based protic salts in water solution. Phys Chem Chem Phys 2019; 21:2691-2696. [PMID: 30657496 DOI: 10.1039/c8cp07254j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Protic ionic liquids containing cations with long alkyl chains can form self-assembled micelles, vesicles, microemulsions, and lyotropic liquid crystal structures in water, acid water or tetrahydrofuran, etc. As a result of this unique property, they are regarded as a novel category of amphiphiles, and are gaining importance in the field of colloid and interface chemistry. The critical micelle concentration (CMC) of protic salts, e.g., alkyl-ammonium nitrates in water, was found to increase with decreasing chain length. It is generally believed that a long alkyl chain length is essential for the formation of self-assembled structures. So far, no self-assembled structure has been reported for protic ionic liquids with an alkyl chain length of n < 4. This paper reports on the structure and dynamics of two imidazolium based protic organic salts with no alkyl chain or a methyl group (n = 1) attached to the cation in water solution, determined through a detailed analysis of NMR spectra and pulsed-field gradient NMR data. We demonstrate that these imidazolium cations with no or a short alkyl chain (n = 1) can form a self-assembled clustering structure in water solution, which has a strong influence on the diffusion behavior of imidazolium molecular ions. It is speculated that this self-assembled structure is likely to be present in other similar solutions of ionic liquids with short alkyl chains.
Collapse
Affiliation(s)
- Haijin Zhu
- Institute for Frontier Materials, Deakin University, 75 Pigdons Rd, Geelong, Victoria 3216, Australia.
| | | | | | | |
Collapse
|
17
|
Fu D, Gao X, Huang B, Wang J, Sun Y, Zhang W, Kan K, Zhang X, Xie Y, Sui X. Micellization, surface activities and thermodynamics study of pyridinium-based ionic liquid surfactants in aqueous solution. RSC Adv 2019; 9:28799-28807. [PMID: 35529658 PMCID: PMC9071189 DOI: 10.1039/c9ra04226a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 09/01/2019] [Indexed: 11/21/2022] Open
Abstract
The micellization and surface activity properties of long-chain pyridinium ionic liquids n-alkyl-3-methylpyridinium bromide ([Cnmpy][Br], n: the carbon numbers of hydrophobic tails, n = 12, 14, 16) in aqueous solution were systematically investigated through electronic conductivity measurement, surface tension, and ultraviolet-absorption spectra. The surface chemical parameters and thermodynamics parameters were obtained. The [Cnmpy][Br] ionic liquids exhibit higher surface activities than conventional surfactants with corresponding alkyl chain lengths. The effects of inorganic salts (LiBr, NaBr, MgBr2), organic alcohols (C2H5OH, C3H7OH, C4H9OH, C5H11OH) and temperature on the critical micelle concentration (CMC) values of [Cnmpy][Br] aqueous solutions were also investigated. The CMC values remarkably decreased with the addition of inorganic salts. The CMC values increased slightly in the presence of ethanol, but decreased gradually as the chain length of the alcohol increased. The CMC values assumed a trend of decreasing and then increasing with the increase of temperature. The calculation results of thermodynamic parameters show that both adsorption and micellization processes of [Cnmpy][Br] are spontaneous; the enthalpy of [C12mpy][Br] is negative at 293.15 K and becomes negative with temperature increasing. For [C14mpy][Br] and [C16mpy][Br] this transition occurs at 288.15 K and the micellization process is entropy-driven in the investigated temperature range. This paper contains details on the micellization, surface activity properties, thermodynamics and effects of additives of [Cnmpy][Br].![]()
Collapse
Affiliation(s)
- Dong Fu
- Heilongjiang Academy of Sciences Institute of Advanced Technology
- Harbin
- China
| | - Xiaoru Gao
- Harbin FRP Research Institute
- Harbin
- China
| | - Bo Huang
- Heilongjiang Academy of Sciences Institute of Advanced Technology
- Harbin
- China
| | - Jue Wang
- Heilongjiang Academy of Sciences Institute of Advanced Technology
- Harbin
- China
| | - Yao Sun
- Heilongjiang Academy of Sciences Institute of Advanced Technology
- Harbin
- China
| | - Weijun Zhang
- Heilongjiang Academy of Sciences Institute of Advanced Technology
- Harbin
- China
| | - Kan Kan
- Heilongjiang Academy of Sciences Institute of Advanced Technology
- Harbin
- China
| | - Xiaochen Zhang
- Heilongjiang Academy of Sciences Institute of Advanced Technology
- Harbin
- China
| | - Yang Xie
- Heilongjiang Academy of Sciences Institute of Advanced Technology
- Harbin
- China
| | - Xin Sui
- Heilongjiang Academy of Sciences Institute of Advanced Technology
- Harbin
- China
| |
Collapse
|
18
|
Brar SK, Kumar S, Pandey SK, Bhasin K, Wangoo N, Sharma RK. Fabrication of self-assembled imidazo[1,2-a]pyridine based materials: Understanding the impact of solvent and chemical modulation. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.01.090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
|