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Lew JH, Matar OK, Müller EA, Luckham PF, Sousa Santos A, Myo Thant MM. Atomic Force Microscopy of Hydrolysed Polyacrylamide Adsorption onto Calcium Carbonate. Polymers (Basel) 2023; 15:4037. [PMID: 37896286 PMCID: PMC10609783 DOI: 10.3390/polym15204037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/28/2023] [Accepted: 10/05/2023] [Indexed: 10/29/2023] Open
Abstract
In this work, the interaction of hydrolysed polyacrylamide (HPAM) of two molecular weights (F3330, 11-13 MDa; F3530, 15-17 MDa) with calcium carbonate (CaCO3) was studied via atomic force microscopy (AFM). In the absence of polymers at 1.7 mM and 1 M NaCl, good agreement with DLVO theory was observed. At 1.7 mM NaCl, repulsive interaction during approach at approximately 20 nm and attractive adhesion of approximately 400 pN during retraction was measured, whilst, at 1 M NaCl, no repulsion during approach was found. Still, a significantly larger adhesion of approximately 1400 pN during retraction was observed. In the presence of polymers, results indicated that F3330 displayed higher average adhesion (450-625 pN) and interaction energy (43-145 aJ) with CaCO3 than F3530's average adhesion (85-88 pN) and interaction energy (8.4-11 aJ). On the other hand, F3530 exerted a longer steric repulsion distance (70-100 nm) than F3330 (30-70 nm). This was likely due to the lower molecular weight. F3330 adopted a flatter configuration on the calcite surface, creating more anchor points with the surface in the form of train segments. The adhesion and interaction energy of both HPAM with CaCO3 can be decreased by increasing the salt concentration. At 3% NaCl, the average adhesion and interaction energy of F3330 was 72-120 pN and 5.6-17 aJ, respectively, while the average adhesion and interaction energy of F3530 was 11.4-48 pN and 0.3-2.98 aJ, respectively. The reduction of adhesion and interaction energy was likely due to the screening of the COO- charged group of HPAM by salt cations, leading to a reduction of electrostatic attraction between the negatively charged HPAM and the positively charged CaCO3.
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Affiliation(s)
- Jin Hau Lew
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK; (O.K.M.); (E.A.M.); (P.F.L.); (A.S.S.)
| | - Omar K. Matar
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK; (O.K.M.); (E.A.M.); (P.F.L.); (A.S.S.)
| | - Erich A. Müller
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK; (O.K.M.); (E.A.M.); (P.F.L.); (A.S.S.)
| | - Paul F. Luckham
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK; (O.K.M.); (E.A.M.); (P.F.L.); (A.S.S.)
| | - Adrielle Sousa Santos
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK; (O.K.M.); (E.A.M.); (P.F.L.); (A.S.S.)
| | - Maung Maung Myo Thant
- PETRONAS Research Sdn. Bhd., Lot 3288 & 3289, Off Jalan Ayer Itam, Kawasan Institusi Bangi, Kajang 43000, Selangor, Malaysia;
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Ouyang Q, Xie Z, Liu J, Gong M, Yu H. Application of Atomic Force Microscopy as Advanced Asphalt Testing Technology: A Comprehensive Review. Polymers (Basel) 2022; 14:polym14142851. [PMID: 35890627 PMCID: PMC9316586 DOI: 10.3390/polym14142851] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 07/08/2022] [Accepted: 07/09/2022] [Indexed: 11/16/2022] Open
Abstract
In the past three decades, researchers have engaged in the relationship between the composition, macro performance, and microstructure of asphalt. There are many research results in the use of atomic force microscopy (AFM) to study the microstructure and related mechanisms of asphalt. Based on previous studies, the performance of asphalt from its microstructure has been observed and analyzed, and different evaluation indices and modification methods have been proposed, providing guidance toward improving the performance of asphalt materials and benefiting potential applications. This review focuses on the typical application and analysis of AFM in the study of the aging regeneration and modification properties of asphalt. Additionally, this review introduces the history of the rheological and chemical testing of asphalt materials and the history of using AFM to investigate asphalt. Furthermore, this review introduces the basic principles of various modes of application of AFM in the microstructure of asphalt, providing a research direction for the further popularization and application of AFM in asphalt or other materials in the future. This review aims to provide a reference and direction for researchers to further popularize the application of AFM in asphalt and standardize the testing methods of AFM. This paper is also helpful in further exploring the relationship between the microstructure and macro performance of asphalt.
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Affiliation(s)
- Qijian Ouyang
- School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510641, China; (Q.O.); (Z.X.); (J.L.)
| | - Zhiwei Xie
- School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510641, China; (Q.O.); (Z.X.); (J.L.)
| | - Jinhai Liu
- School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510641, China; (Q.O.); (Z.X.); (J.L.)
| | - Minghui Gong
- State Key Laboratory of High Performance Civil Engineering Materials, Nanjing 210096, China;
| | - Huayang Yu
- School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510641, China; (Q.O.); (Z.X.); (J.L.)
- State Key Laboratory of High Performance Civil Engineering Materials, Nanjing 210096, China;
- Guangdong Provincial Key Laboratory of Modern Civil Engineering Technology, Guangzhou 510641, China
- Correspondence:
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Current Research and Challenges in Bitumen Emulsion Manufacturing and Its Properties. MATERIALS 2022; 15:ma15062026. [PMID: 35329476 PMCID: PMC8952829 DOI: 10.3390/ma15062026] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/02/2022] [Accepted: 03/04/2022] [Indexed: 11/17/2022]
Abstract
The global increase of road infrastructure and its impact on the environment requires serious attention to develop sustainable and environmentally friendly road materials. One group of those materials is produced by using bitumen emulsion. However, there are still scientific and technical obstacles standing against its regular application. The bitumen emulsion formulation process and compositional optimization are subjected to a high number of degrees of freedom. Consequently, obtaining the desired product is mostly based on a series of random and tedious trials because of the enormous number of tests that are carried out to meet the required properties, such as emulsion stability, viscosity, droplet size (and distribution), and bitumen emulsion chemistry. Several pre-established formulation procedures have been presented in the literature. Some of them have technical limitations to be utilized for practical industrial application, whereas others are still not understood enough to be applied in bitumen emulsion formulation. Therefore, discussing some important issues in this field could be useful to offer a practical guide for bitumen emulsion manufacturers when trying to formulate a well-defined bitumen emulsion to best fit its use in pavement infrastructure rather than to simply to meet standard specifications. This review paper aims to enable the ultimate potential of bitumen emulsion by further reviewing the research progress of bitumen emulsion manufacturing and discussing the literature available up to now on this topic, in the realm of bitumen emulsion manufacturing and emulsion chemistry.
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Sun W, Zeng H, Tang T. Enhanced Adsorption of Anionic Polymer on Montmorillonite by Divalent Cations and the Effect of Salinity. J Phys Chem A 2021; 125:1025-1035. [PMID: 33494601 DOI: 10.1021/acs.jpca.0c08797] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Adsorption of polymers from an aqueous solution onto clay minerals is of great interest to many applications such as water purification and soil conditioning. Molecular dynamics simulations were performed to study the adsorption of anionic polyacrylamide (APAM) on anionic montmorillonite, in an aqueous solution containing monovalent or divalent salts. Compared with monovalent salts (NaCl), the enhancement of APAM adsorption brought by divalent salts (CaCl2) was significant, which could not be explained by the Poisson-Boltzmann theory alone. Each solvated Ca2+ was coordinated by 4-6 water oxygens in its first coordination shell. One to two of these water molecules were displaced when APAM formed a complex with Ca2+. Ca2+ ions in the adsorbed Ca2+-APAM complexes did not serve as bridges sandwiched between APAM and Mt; instead, the complexes carried a residual positive charge and were subsequently attracted to montmorillonite. The number of adsorbed Ca2+-APAM complexes changed with salinity in a nonmonotonic manner, due to the modulation of apparent charges of montmorillonite and APAM by Ca2+. Increasing adsorption of Ca2+-APAM complexes also promoted APAM adsorption through direct hydrogen bonding with montmorillonite. The findings provided new molecular insights into the long-standing debates on the role of divalent ions in promoting polymer adsorption on like-charged solid surfaces.
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Affiliation(s)
- Wenyuan Sun
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Hongbo Zeng
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Tian Tang
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
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5
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Micellar thermodynamic behavior of branch-modified xanthan gum and aggregating structures in aqueous and saline solutions. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2019.124317] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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6
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Xing Y, Xu M, Gui X, Cao Y, Babel B, Rudolph M, Weber S, Kappl M, Butt HJ. The application of atomic force microscopy in mineral flotation. Adv Colloid Interface Sci 2018; 256:373-392. [PMID: 29559086 DOI: 10.1016/j.cis.2018.01.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 01/29/2018] [Accepted: 01/29/2018] [Indexed: 11/30/2022]
Abstract
During the past years, atomic force microscopy (AFM) has matured to an indispensable tool to characterize nanomaterials in colloid and interface science. For imaging, a sharp probe mounted near to the end of a cantilever scans over the sample surface providing a high resolution three-dimensional topographic image. In addition, the AFM tip can be used as a force sensor to detect local properties like adhesion, stiffness, charge etc. After the invention of the colloidal probe technique it has also become a major method to measure surface forces. In this review, we highlight the advances in the application of AFM in the field of mineral flotation, such as mineral morphology imaging, water at mineral surface, reagent adsorption, inter-particle force, and bubble-particle interaction. In the coming years, the complementary characterization of chemical composition such as using infrared spectroscopy and Raman spectroscopy for AFM topography imaging and the synchronous measurement of the force and distance involving deformable bubble as a force sensor will further assist the fundamental understanding of flotation mechanism.
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Affiliation(s)
- Yaowen Xing
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China; Chinese National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, China; Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Mengdi Xu
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China
| | - Xiahui Gui
- Chinese National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, China; Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
| | - Yijun Cao
- Chinese National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, China; Henan Province Industrial Technology Research Institute of Resources and Materials, Zhengzhou University, Zhengzhou 450001, China.
| | - Bent Babel
- Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Chemnitzer Str. 40, 09599 Freiberg, Germany
| | - Martin Rudolph
- Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Chemnitzer Str. 40, 09599 Freiberg, Germany
| | - Stefan Weber
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Michael Kappl
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
| | - Hans-Jürgen Butt
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
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Tang Y, Zhang X, Choi P, Liu Q, Xu Z. Probing Single-Molecule Adhesion of a Stimuli Responsive Oligo(ethylene glycol) Methacrylate Copolymer on a Molecularly Smooth Hydrophobic MoS 2 Basal Plane Surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:10429-10438. [PMID: 28898088 DOI: 10.1021/acs.langmuir.7b01187] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Molybdenum disulfide (MoS2) has been receiving increasing attention in scientific research due to its unique properties. Up to now, several techniques have been developed to prepare exfoliated nanosize MoS2 dispersions to facilitate its applications. To improve its desired performance, as-prepared MoS2 dispersion needs further appropriate modification by polymers. Thus, understanding polymer-MoS2 interaction is of great scientific importance and practical interest. Here, we report our results on molecular interactions of a biocompatible stimuli-responsive copolymer with the basal plane surface of MoS2 determined using single molecule force spectroscopy (SMFS). Under isothermal conditions, the single-molecule adhesion force of oligo(ethylene glycol) methacrylate copolymer was found to increase from 50 to 75 pN with increasing NaCl concentration from 1 mM to 2 M, as a result of increasing hydrophobicity of the polymers. The theoretical analysis demonstrated that single-molecule adhesion force is determined by two contributions: the adhesion energy per monomer and the entropic free energy of the stretched polymer chain. Further data analysis revealed a significant increase in the adhesion energy per monomer with a negligible change in the other contribution with increasing salt concentration. The hydrophobic attraction (HA) was found to be the main contribution for the higher adhesion energy in electrolyte solutions of higher NaCl concentrations where the zero-frequency of van der Waals interaction were effectively screened. The results illustrate that oligo(ethylene glycol) methacrylate copolymer is a promising polymer for functionalizing MoS2 and that one can simply change the salt concentration to modulate the single-molecule interactions for desired applications.
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Affiliation(s)
- Yuechao Tang
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
| | - Xurui Zhang
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
| | - Phillip Choi
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
| | - Qingxia Liu
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
| | - Zhenghe Xu
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
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Liu G, Yu S, Yang H, Hu J, Zhang Y, He B, Li L, Liu Z. Molecular Mechanisms of Ultrafiltration Membrane Fouling in Polymer-Flooding Wastewater Treatment: Role of Ions in Polymeric Fouling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:1393-1402. [PMID: 26735590 DOI: 10.1021/acs.est.5b04098] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Polymer (i.e., anionic polyacrylamide (APAM)) fouling of polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes and its relationships to intermolecular interactions were investigated using atomic force microscopy (AFM). Distinct relations were obtained between the AFM force spectroscopy measurements and calculated fouling resistance over the concentration polarization layer (CPL) and gel layer (GL). The measured maximum adhesion forces (Fad,max) were closely correlated with the CPL resistance (Rp), and the proposed molecular packing property (largely based on the shape of AFM force spectroscopy curve) of the APAM chains was related to the GL resistance (Rg). Calcium ions (Ca(2+)) and sodium ions (Na(+)) caused more severe fouling. In the presence of Ca(2+), the large Rp corresponded to high foulant-foulant Fad,max, resulting in high flux loss. In addition, the Rg with Ca(2+) was minor, but the flux recovery rate after chemical cleaning was the lowest, indicating that Ca(2+) created more challenges in GL cleaning. With Na(+), the fouling behavior was complicated and concentration-dependent. The GL structures with Na(+), which might correspond to the proposed molecular packing states among APAM chains, played essential roles in membrane fouling and GL cleaning.
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Affiliation(s)
- Guicai Liu
- School of Environmental Science and Engineering; State Key Laboratory of Pollution Control and Resource Reuse, Tongji University , Shanghai, China , 200092
| | - Shuili Yu
- School of Environmental Science and Engineering; State Key Laboratory of Pollution Control and Resource Reuse, Tongji University , Shanghai, China , 200092
| | - Haijun Yang
- Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences , PO Box 800-204, Shanghai 201800, P.R. China
| | - Jun Hu
- Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences , PO Box 800-204, Shanghai 201800, P.R. China
| | - Yi Zhang
- Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences , PO Box 800-204, Shanghai 201800, P.R. China
| | - Bo He
- Shandong Academy of Environmental Science ; Jinan, China , 250013
| | - Lei Li
- School of Environmental Science and Engineering; State Key Laboratory of Pollution Control and Resource Reuse, Tongji University , Shanghai, China , 200092
| | - Zhiyuan Liu
- School of Environmental Science and Engineering; State Key Laboratory of Pollution Control and Resource Reuse, Tongji University , Shanghai, China , 200092
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Luo Z, Cheng B, Cui S. Effects of Water on the Single-Chain Elasticity of Poly(U) RNA. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:6107-6113. [PMID: 25989243 DOI: 10.1021/acs.langmuir.5b01313] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Water, the dominant component under the physiological condition, is a complicated solvent which greatly affects the properties of solute molecules. Here, we utilize atomic force microscope-based single-molecule force spectroscopy to study the influence of water on the single-molecule elasticity of an unstructured single-stranded RNA (poly(U)). In nonpolar solvents, RNA presents its inherent elasticity, which is consistent with the theoretical single-chain elasticity calculated by quantum mechanics calculations. In aqueous buffers, however, an additional energy of 1.88 kJ/mol·base is needed for the stretching of the ssRNA chain. This energy is consumed by the bound water rearrangement (Ew) during chain elongation. Further experimental results indicate that the Ew value is uncorrelated to the salt concentrations and stretching velocity. The results obtained in an 8 M guanidine·HCl solution provide more evidence that the bound water molecules around RNA give rise to the observed deviation between aqueous and nonaqueous environments. Compared to synthetic water-soluble polymers, the value of Ew of RNA is much lower. The weak interference of water is supposed to be the precondition for the RNA secondary structure to exist in aqueous solution.
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Affiliation(s)
- Zhonglong Luo
- Key Lab of Advanced Technologies of Materials, Ministry of Education of China, Southwest Jiaotong University, Chengdu 610031, China
| | - Bo Cheng
- Key Lab of Advanced Technologies of Materials, Ministry of Education of China, Southwest Jiaotong University, Chengdu 610031, China
| | - Shuxun Cui
- Key Lab of Advanced Technologies of Materials, Ministry of Education of China, Southwest Jiaotong University, Chengdu 610031, China
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Effect of solution salinity on settling of mineral tailings by polymer flocculants. Colloids Surf A Physicochem Eng Asp 2013. [DOI: 10.1016/j.colsurfa.2013.04.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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11
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Klein C, Harbottle D, Alagha L, Xu Z. Impact of fugitive bitumen on polymer-based flocculation of mature fine tailings. CAN J CHEM ENG 2013. [DOI: 10.1002/cjce.21863] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Colin Klein
- Department of Chemical and Materials Engineering; University of Alberta; Edmonton; AB; Canada
| | - David Harbottle
- Department of Chemical and Materials Engineering; University of Alberta; Edmonton; AB; Canada
| | | | - Zhenghe Xu
- Department of Chemical and Materials Engineering; University of Alberta; Edmonton; AB; Canada
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Wang K, Pang X, Cui S. Inherent stretching elasticity of a single polymer chain with a carbon-carbon backbone. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:4315-4319. [PMID: 23477592 DOI: 10.1021/la400626x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We study the single-chain elasticities of three kinds of neutral polymers with a carbon-carbon (C-C) backbone by atomic force microscopy-based single-molecule force spectroscopy in a nonpolar solvent (octane), aiming at measuring the inherent chain elasticity of this very important class of polymers. The finding that the single-chain elasticities of all three polymers in octane are virtually identical in the entire force region implies that the side chains of the polymers have no detectable effects on the single-chain elasticity. By utilizing the single-chain elasticity from quantum mechanics calculations, the freely rotating chain model can provide the best fitting curve when each C-C bond is set to be the rotating unit. Although there are some exceptions when the side chain is very huge, our work provides a general result for the inherent elasticity of single neutral flexible polymer chains with C-C backbones.
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Affiliation(s)
- Kefeng Wang
- Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
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Al-Hashmi A, Luckham P, Al-Maamari R, Zaitoun A, Al-Sharji H. The role of hydration degree of cations and anions on the adsorption of high-molecular-weight nonionic polyacrylamide on glass surfaces. Colloids Surf A Physicochem Eng Asp 2012. [DOI: 10.1016/j.colsurfa.2012.09.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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14
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Zhang L, Lu Q, Xu Z, Liu Q, Zeng H. Effect of polycarboxylate ether comb-type polymer on viscosity and interfacial properties of kaolinite clay suspensions. J Colloid Interface Sci 2012; 378:222-31. [DOI: 10.1016/j.jcis.2012.04.029] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 04/09/2012] [Accepted: 04/10/2012] [Indexed: 10/28/2022]
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15
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Cui S, Pang X, Zhang S, Yu Y, Ma H, Zhang X. Unexpected temperature-dependent single chain mechanics of poly(N-isopropyl-acrylamide) in water. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:5151-5157. [PMID: 22352698 DOI: 10.1021/la300135w] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Poly(N-isopropyl-acrylamide) (PNIPAM) is a paradigm thermally sensitive polymer, which has a lower critical solution temperature (LCST) of ~32 °C in water. Herein by AFM-based single molecule force spectroscopy (SMFS), we measured the single chain elasticity of PNIPAM across the LCST in water. Below LCST, the force curves obtained at different temperatures have no remarkable difference; while above LCST, an unexpected temperature dependent elasticity is observed, mainly in the middle force regime. We found that 35 °C is a turning point of the variation: from 31 to 35 °C, the middle parts of the force curves drop gradually, whereas from 35 to 40 °C, the middle parts rise gradually. A possible mechanism for the unexpected temperature dependent mechanics is proposed. The single chain contraction against external force upon heating from 35 to 40 °C may cast new light on the design of molecular devices that convert thermal energy to mechanical work.
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Affiliation(s)
- Shuxun Cui
- Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China.
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Ozkaya B, Ozcan O, Thissen P, Grundmeier G. Single molecule desorption studies on immobilized nanoclay particle surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:8155-8160. [PMID: 20230055 DOI: 10.1021/la904465t] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
AFM-based single molecule force spectroscopy was performed on sheetlike inorganic particles of Na-montmorillonite to study the pH-dependent adsorption and desorption behavior of polyelectrolytes in aqueous solutions. Polyallylamine macromolecules were covalently attached on gold-coated AFM cantilevers. Heterogeneous surfaces were formed by immobilizing the nanoclay sheets on mica-stripped ultraflat Au(111) surfaces using aminothiol chemistry. Because of the constant surface charge of the particles over a wide pH range, polymer line charge density was the only parameter that affected the adsorption and desorption behavior when the ionic concentration was kept constant. Polarization modulation infrared-reflection absorption spectroscopy (PM-IRRAS) was performed on cast polyallylamine films to study the pH-dependent charge density of polyallylamine molecules. A good correlation was found between the line charge density and the adsorption characteristics of polyallylamine.
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Affiliation(s)
- Berkem Ozkaya
- Max-Planck-Insitut fuer Eisenforschung GmbH, Max-Planck-Strasse 1, D-40237 Dusseldorf, Germany
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17
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Sun W, Long J, Xu Z, Masliyah JH. Study of Al(OH)3-polyacrylamide-induced pelleting flocculation by single molecule force spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:14015-14021. [PMID: 19360955 DOI: 10.1021/la802537z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A nanocomposite polymer, Al(OH)3-polyacrylamide (Al-PAM) hybrid, was tested as a flocculant. This novel hybrid polymer was found to induce pellet-like floccules, leading to a more effective solid-liquid separation than common polyacrylamide (PAM)-based flocculants. To understand the mechanism of Al-PAM-induced pelleting flocculation, the molecular structure of this hybrid polymer was studied using an atomic force microscope (AFM). The interactions between Al-PAM molecules and a silica surface were measured using single molecule force spectroscopy (SMFS). The Al-PAM molecules were found to have a star-like structure with Al(OH)3 colloidal particles as cores connecting PAM chains. The SMFS results showed a strong attachment of the Al(OH)3 cores to the silica surface with an adhesion force of approximately 1250 pN, in contrast to a weaker adhesion force of only approximately 250 pN for PAM chains on the silica surface. The Al-PAM-induced pelleting flocculation is attributed to its star-like structure.
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Affiliation(s)
- Wei Sun
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2G6
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Matsumoto N, Fujita M, Hiraishi T, Abe H, Maeda M. Adsorption Characteristics of P(3HB) Depolymerase as Evaluated by Surface Plasmon Resonance and Atomic Force Microscopy. Biomacromolecules 2008; 9:3201-7. [DOI: 10.1021/bm800790q] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Nobuhiko Matsumoto
- Department of Innovative and Engineered Materials, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8501, Japan, Bioengeering Laboratory, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan, and Chemical Analysis Team, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan
| | - Masahiro Fujita
- Department of Innovative and Engineered Materials, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8501, Japan, Bioengeering Laboratory, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan, and Chemical Analysis Team, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan
| | - Tomohiro Hiraishi
- Department of Innovative and Engineered Materials, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8501, Japan, Bioengeering Laboratory, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan, and Chemical Analysis Team, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan
| | - Hideki Abe
- Department of Innovative and Engineered Materials, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8501, Japan, Bioengeering Laboratory, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan, and Chemical Analysis Team, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan
| | - Mizuo Maeda
- Department of Innovative and Engineered Materials, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8501, Japan, Bioengeering Laboratory, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan, and Chemical Analysis Team, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan
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19
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Long J, Drelich J, Xu Z, Masliyah JH. Effect of Operating Temperature on Water-Based Oil Sands Processing. CAN J CHEM ENG 2008. [DOI: 10.1002/cjce.5450850518] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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20
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Zhang Z, Tomlinson MR, Golestanian R, Geoghegan M. The interfacial behaviour of single poly(N,N-dimethylacrylamide) chains as a function of pH. NANOTECHNOLOGY 2008; 19:035505. [PMID: 21817573 DOI: 10.1088/0957-4484/19/03/035505] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We have studied the pH-dependent conformational behaviour of poly(N,N-dimethylacrylamide) (PDMAc) at silicon and gold surfaces using single-molecule force spectroscopy and a quartz crystal microbalance (QCM). Despite the pH dependence, nuclear magnetic resonance and titration experiments demonstrate that PDMAc is not a weak polybase. The interaction between single chains and a silicon surface (with native oxide layer intact) in aqueous solution was investigated using force spectroscopy. Single-molecule force measurements were performed using thiol-functionalized PDMAc and gold-coated AFM cantilevers. The forces of interaction between PDMAc and the native oxide-coated silicon surface vary with the pH. The shape of the retraction curve for low pH solution includes a greater number of 'train' conformations, which suggests a stronger interaction with the surface relative to the surrounding media at low pH. The adsorption behaviour of PDMAc, from liquid onto silicon surfaces, was monitored using a QCM, which shows greater PDMAc adsorption onto silicon at low pH. The force spectroscopy and QCM investigations confirm that the PDMAc chain is more extended and stiffer in low pH solution. We attribute the pH-dependent behaviour to an increased number of hydrogen bonding sites on the silicon surface at low pH.
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Affiliation(s)
- Z Zhang
- Department of Physics and Astronomy, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH, UK
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21
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Rodríguez-Valverde MA, Ramón-Torregrosa P, Páez-Dueñas A, Cabrerizo-Vílchez MA, Hidalgo-Alvarez R. Imaging techniques applied to characterize bitumen and bituminous emulsions. Adv Colloid Interface Sci 2008; 136:93-108. [PMID: 17825782 DOI: 10.1016/j.cis.2007.07.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2007] [Revised: 07/19/2007] [Accepted: 07/30/2007] [Indexed: 11/16/2022]
Abstract
The purpose of this article is to present some important advances in the imaging techniques currently used in the characterization of bitumen and bituminous emulsions. Bitumen exhibits some properties, such as a black colour and a reflecting surface at rest, which permit the use of optical techniques to study the macroscopic behaviour of asphalt mixes in the cold mix technology based on emulsion use. Imaging techniques allow monitoring in situ the bitumen thermal sensitivity as well as the complex phenomenon of emulsion breaking. Evaporation-driven breaking was evaluated from the shape of evaporating emulsion drops deposited onto non-porous and hydrophobic substrates. To describe the breaking kinetics, top-view images of a drying emulsion drop placed on an aggregate sheet were acquired and processed properly. We can conclude that computer-aided image analysis in road pavement engineering can elucidate the mechanism of breaking and curing of bituminous emulsion.
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Affiliation(s)
- M A Rodríguez-Valverde
- Biocolloid and Fluid Physics Group, Department of Applied Physics, Faculty of Sciences, University of Granada, Fuentenueva Campus, E-18071 Granada, Spain
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22
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Li H, Long J, Xu Z, Masliyah JH. Effect of molecular weight and charge density on the performance of polyacrylamide in low-grade oil sand ore processing. CAN J CHEM ENG 2008. [DOI: 10.1002/cjce.20029] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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23
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Roiter Y, Minko S. Adsorption of Polyelectrolyte versus Surface Charge: in Situ Single-Molecule Atomic Force Microscopy Experiments on Similarly, Oppositely, and Heterogeneously Charged Surfaces. J Phys Chem B 2007; 111:8597-604. [PMID: 17555343 DOI: 10.1021/jp070518q] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have studied the effect of the pH and surface charge of mica on the adsorption of the positively charged weak polyelectrolyte (PE) poly(2-vinylpyridine) (P2VP) using atomic force microscopy (AFM) single-molecule experiments. These AFM experiments were performed in situ directly under aqueous media. If the mica's surface and the PE are oppositely charged (pH > 3), the PE forms a flat adsorbed layer of two-dimensionally (2D) equilibrated self-avoiding random walk coils. The adsorbed layer's structure remains almost unchanged if the pH is decreased to pH 3 (the mica's surface is weakly charged). At pH 2 (the mica surface is decorated by spots of different electrical charges), the polyelectrolyte chains take the form of a 2D compressed coil. In this pH range, at an increased P2VP concentration in solution, the PE segments preferentially adsorb onto the top of previously adsorbed segments, rather than onto an unoccupied surface. We explain this behavior as being caused by the heterogeneous character of the charged surface and the competitive adsorption of hydronium ions. The further increase of polymer concentration results in a complete coverage of the mica substrate and the charge overcompensation by P2VP chains adsorbed on the similarly charged substrate, due to van der Waals forces.
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Affiliation(s)
- Yuri Roiter
- Clarkson University, Department of Chemistry and Biomolecular Science, 8 Clarkson Avenue, Potsdam, New York 13699-5810, USA
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24
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The unwinding of surfactant-induced helical structure of carboxymethyl amylose by single molecule force spectroscopy. POLYMER 2007. [DOI: 10.1016/j.polymer.2007.02.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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25
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Molecular morphology of modified partially hydrolyzed polyacrylamide (MHPAM) on mica substrates and Langmuir–Blodgett films of MHPAM/CTAB complexes as observed by AFM. Eur Polym J 2007. [DOI: 10.1016/j.eurpolymj.2006.12.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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26
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Gil R, Guillerez MG, Poulin JC, Schulz E. Charge-transfer complex study by chemical force spectroscopy: a dynamic force spectroscopic approach. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:542-8. [PMID: 17209605 DOI: 10.1021/la062169h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Charge-transfer interaction, as a reversible and rapid phenomenon, was evidenced by force microscopy. Pull-off forces were measured between a tip grafted with a trinitrofluorenone derivative and a surface functionalized with an electron-rich aromatic anthracene compound in a dodecane environment. The effect of the sweep time on the measured interaction forces is described, together with an extensive study of a competitive influence of free aromatic molecules in dodecane diluted solutions. These forces depend on the nature of the competitor and its concentration as well as on the velocity of tip/sample separation.
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Affiliation(s)
- Richard Gil
- Equipe Catalyse Moléculaire, Institut de Chimie Moléculaire et des Matériaux d'Orsay, UMR 8182, Université Paris-Sud, Bât 420, 91405 Orsay Cedex, France
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27
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Liu C, Wang Z, Zhang X. Force Spectroscopy of Single-Chain Polysaccharides: Force-Induced Conformational Transition of Amylose Disappears under Environment of Micelle Solution. Macromolecules 2006. [DOI: 10.1021/ma060054e] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Chuanjun Liu
- Key Lab of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084, People's Republic of China, and Key Lab for Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, People's Republic of China
| | - Zhiqiang Wang
- Key Lab of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084, People's Republic of China, and Key Lab for Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, People's Republic of China
| | - Xi Zhang
- Key Lab of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084, People's Republic of China, and Key Lab for Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, People's Republic of China
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