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Schulze-Zachau F, Bachmann S, Braunschweig B. Effects of Ca 2+ Ion Condensation on the Molecular Structure of Polystyrene Sulfonate at Air-Water Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:11714-11722. [PMID: 30188134 PMCID: PMC6170951 DOI: 10.1021/acs.langmuir.8b02631] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/05/2018] [Indexed: 06/02/2023]
Abstract
The structure of poly(sodium 4-styrenesulfonate) (NaPSS) polyelectrolytes at air-water interfaces was investigated with tensiometry, ellipsometry, and vibrational sum-frequency generation (SFG) in the presence of low and high CaCl2 concentrations. In addition, we have studied the foaming behavior of 20 mM NaPSS solutions to relate the PSS molecular structure at air-water interfaces to foam properties. PSS polyelectrolytes without additional salt exhibited significant surface activity, which can be tuned further by additions of CaCl2. The hydrophobicity of the backbone due to incomplete sulfonation during synthesis is one origin, whereas the effective charge of the polyelectrolyte chain is shown to play another major role. At low salt concentrations, we propose that the polyelectrolyte is forming a layered structure. The hydrophobic parts are likely to be located directly at the interface in loops, whereas the hydrophilic parts are at low concentrations stretched out into near-interface regions in tails. Increasing the Ca2+ concentration leads to ion condensation, a collapse of the tails, and likely to Ca2+ intra- and intermolecular bridges between polyelectrolytes at the interface. The increase in both surface excess and foam stability originates from changes in the polyelectrolyte's hydrophobicity due to Ca2+ condensation onto the PSS polyanions. Consequently, charge screening at the interface is enhanced and repulsive electrostatic interactions are reduced. Furthermore, SFG spectra of O-H stretching bands reveal a decrease in intensity of the low-frequency branch when c(Ca2+) is increased whereas the high-frequency branch of O-H stretching modes persists even for 1 M CaCl2. This originates from the remaining net charge of the PSS polyanions at the air-water interface that is not fully compensated by condensation of Ca2+ ions and leads to electric-field-induced contributions to the SFG spectra of interfacial H2O. A charge reversal of the PSS net charge at the air-water interface is not observed and is consistent with bulk electrophoretic mobility measurements.
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Affiliation(s)
- Felix Schulze-Zachau
- Institute
of Physical Chemistry and Center for Soft Nanoscience, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, 48149 Münster, Germany
| | - Silvia Bachmann
- Institute
of Particle Technology (LFG), Friedrich-Alexander-Universität
Erlangen-Nürnberg (FAU), Cauerstraße 4, 91058 Erlangen, Germany
| | - Björn Braunschweig
- Institute
of Physical Chemistry and Center for Soft Nanoscience, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, 48149 Münster, Germany
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Kim HC, Arick DQ, Won YY. Air-Water Interfacial Properties of Chloroform-Spread versus Water-Spread Poly((d,l-lactic acid- co-glycolic acid)- block-ethylene glycol) (PLGA-PEG) Polymers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:4874-4887. [PMID: 29602280 DOI: 10.1021/acs.langmuir.8b00566] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Polymers at fluid interfaces are used for a number of applications that include coatings, electronics, separation, energy, cosmetics, and medicines. Here, we present a study on an amphiphilic block copolymer, poly((d,l-lactic acid- co-glycolic acid)- block-ethylene glycol) (PLGA-PEG), at the air-water interface. PLGA-PEG at the air-water interface prepared by using an organic spreading solvent exhibits an extremely high surface pressure without the occurrence of desorption, making it an attractive candidate for a variety of uses in the areas mentioned above. The origin of this high surface pressure increase was shown to be due to the glass transition of the PLGA segments. The temperature at which this glass transition occurs for the PLGA segments of PLGA-PEG at the air-water interface was measured to be about 290 K by thermodynamic analysis based on the two-dimensional Maxwell relations. However, from an applications standpoint, spreading by an organic solvent greatly limits its scope of feasible uses. To explore the possibility of maintaining the excellent surface mechanical properties of the PLGA-PEG at the air-water interface while not using an organic solvent, we investigated the air-water interfacial properties of water-spread PLGA-PEG. When spread with water, it was shown that the initial micelles that form in the aqueous spreading solution remain intact even after being spread onto the air-water interface. Due to this different morphology, the surface pressure and monolayer stability were greatly reduced for the water-spread PLGA-PEG at the air-water interface. We used the Daoud and Cotton's blob scaling model to describe the desorption process of the water-spread PLGA-PEG at the air-water interface. From the scaling concept, it was shown that with higher PEG molecular weight and larger micelle size, the adsorption energy of the water-spread PLGA-PEG to the air-water interface was increased.
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Affiliation(s)
- Hyun Chang Kim
- School of Chemical Engineering , Purdue University , West Lafayette , Indiana 47907 , United States
| | - Davis Q Arick
- School of Chemical Engineering , Purdue University , West Lafayette , Indiana 47907 , United States
| | - You-Yeon Won
- School of Chemical Engineering , Purdue University , West Lafayette , Indiana 47907 , United States
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Raffa P, Wever DAZ, Picchioni F, Broekhuis AA. Polymeric Surfactants: Synthesis, Properties, and Links to Applications. Chem Rev 2015; 115:8504-63. [PMID: 26182291 DOI: 10.1021/cr500129h] [Citation(s) in RCA: 184] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Patrizio Raffa
- Department of Chemical Engineering-Product Technology, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Dutch Polymer Institute DPI , P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Diego Armando Zakarias Wever
- Department of Chemical Engineering-Product Technology, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Dutch Polymer Institute DPI , P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Francesco Picchioni
- Department of Chemical Engineering-Product Technology, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Antonius A Broekhuis
- Department of Chemical Engineering-Product Technology, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
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Analysis of biosurfaces by neutron reflectometry: from simple to complex interfaces. Biointerphases 2015; 10:019014. [PMID: 25779088 DOI: 10.1116/1.4914948] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Because of its high sensitivity for light elements and the scattering contrast manipulation via isotopic substitutions, neutron reflectometry (NR) is an excellent tool for studying the structure of soft-condensed material. These materials include model biophysical systems as well as in situ living tissue at the solid-liquid interface. The penetrability of neutrons makes NR suitable for probing thin films with thicknesses of 5-5000 Å at various buried, for example, solid-liquid, interfaces [J. Daillant and A. Gibaud, Lect. Notes Phys. 770, 133 (2009); G. Fragneto-Cusani, J. Phys.: Condens. Matter 13, 4973 (2001); J. Penfold, Curr. Opin. Colloid Interface Sci. 7, 139 (2002)]. Over the past two decades, NR has evolved to become a key tool in the characterization of biological and biomimetic thin films. In the current report, the authors would like to highlight some of our recent accomplishments in utilizing NR to study highly complex systems, including in-situ experiments. Such studies will result in a much better understanding of complex biological problems, have significant medical impact by suggesting innovative treatment, and advance the development of highly functionalized biomimetic materials.
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Xu J, Yang L, Hu X, Xu S, Wang J, Feng S. The effect of polysaccharide types on adsorption properties of LbL assembled multilayer films. SOFT MATTER 2015; 11:1794-1799. [PMID: 25609027 DOI: 10.1039/c4sm02699c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Three types of biocompatible films were fabricated via electrostatic layer-by-layer (LbL) adsorption of oppositely charged cationic polyurethane and anionic polysaccharides with different primary structures, including sodium hyaluronate, sodium carboxymethyl cellulose and sodium alginate. The adsorption behaviors of films were investigated by using the cationic dye methylene blue (MB) as a model drug at various pH values and salt concentrations. The relationship between the type of polysaccharide and the adsorption behavior of LbL films was comparatively studied. It was found that the adsorption capacity increased with an increase of the initial concentration of MB in the concentration range of the experiment to all of the films, and the pH of environment ranged from 3.0 to 9.0. The Langmuir equation fit perfectly to the experiment data. In addition, a pseudo second-order adsorption model can well describe the adsorption behaviors of MB for three films. The results showed that the type of side chains and the charge density of the polysaccharides played key roles in the adsorption properties of the PU/polysaccharide multilayer films.
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Affiliation(s)
- Jie Xu
- Key Laboratory of Oil & Gas Fine Chemicals, Ministry of Education & Xinjiang Uyghur Autonomous Region, College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi, 830046, P. R. China.
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Ghosh A, Yusa SI, Matsuoka H, Saruwatari Y. Chain length dependence of non-surface activity and micellization behavior of cationic amphiphilic diblock copolymers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:3319-3328. [PMID: 24611761 DOI: 10.1021/la403042p] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The cationic and anionic amphiphilic diblock copolymers with a critical chain length and block ratio do not adsorb at the air/water interface but form micelles in solution, which is a phenomenon called "non-surface activity". This is primarily due to the high charge density of the block copolymer, which creates a strong image charge effect at the air/water interface preventing adsorption. Very stable micelle formation in bulk solution could also play an important role in the non-surface activity. To further confirm these unique properties, we studied the adsorption and micellization behavior of cationic amphiphilic diblock copolymers of poly(n-butyl acrylate)-b-poly(3-(methacryloyloxy)ethyl)trimethylammonium chloride) (PBA-b-PDMC) with different molecular weights of hydrophobic blocks but with the same ionic block length. These block copolymers were successfully prepared via consecutive reversible addition-fragmentation chain transfer (RAFT) polymerization. The block copolymer with the shortest hydrophobic block length was surface-active; the solution showed surface tension reduction and foam formation. However, above the critical block ratio, the surface tension of the solution did not decrease with increasing polymer concentration, and there was no foam formation, indicating lack of surface activity. After addition of 0.1 M NaCl, stable foam formation and slight reduction of surface tension were observed, which is reminiscent of the electrostatic nature of the non-surface activity. Fluorescence and dynamic and static light scattering measurements showed that the copolymer with the shortest hydrophobic block did not form micelles, while the block copolymers formed spherical micelles having radii of 25-30 nm. These observations indicate that micelle formation is also important for non-surface activity. Upon addition of NaCl, cmc did not decrease but rather increased as observed for non-surface-active block copolymers previously studied. The micelles formed were very stable, and their size decreased by only ∼5 nm after addition of 0.1 M NaCl.
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Affiliation(s)
- Arjun Ghosh
- Department of Polymer Chemistry, Kyoto University , Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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Matsuoka H, Onishi T, Ghosh A. pH-responsive non-surface-active/surface-active transition of weakly ionic amphiphilic diblock copolymers. Colloid Polym Sci 2013. [DOI: 10.1007/s00396-013-3125-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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8
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Matsuoka H, Hachisuka M, Uda K, Onishi T, Ozoe S. Why Ionic Amphiphilic “Block” Copolymer Can Be Non-surface Active? Comparison of Homopolymer, Block and Random Copolymers of Poly(styrenesulfonate). CHEM LETT 2012. [DOI: 10.1246/cl.2012.1063] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
| | | | - Kyohei Uda
- Department of Polymer Chemistry, Kyoto University
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Ghosh A, Yusa SI, Matsuoka H, Saruwatari Y. Non-surface activity and micellization behavior of cationic amphiphilic block copolymer synthesized by reversible addition-fragmentation chain transfer process. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:9237-9244. [PMID: 21667918 DOI: 10.1021/la201550a] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Cationic amphiphilic diblock copolymers of poly(n-butylacrylate)-b-poly(3-(methacryloylamino)propyl)trimethylammonium chloride) (PBA-b-PMAPTAC) with various hydrophobic and hydrophilic chain lengths were synthesized by a reversible addition-fragmentation chain transfer (RAFT) process. Their molecular characteristics such as surface activity/nonactivity were investigated by surface tension measurements and foam formation observation. Their micelle formation behavior and micelle structure were investigated by fluorescence probe technique, static and dynamic light scattering (SLS and DLS), etc., as a function of hydrophilic and hydrophobic chain lengths. The block copolymers were found to be non-surface active because the surface tension of the aqueous solutions did not change with increasing polymer concentration. Critical micelle concentration (cmc) of the polymers could be determined by fluorescence and SLS measurements, which means that these polymers form micelles in bulk solution, although they were non-surface active. Above the cmc, the large blue shift of the emission maximum of N-phenyl-1-naphthylamine (NPN) probe and the low micropolarity value of the pyrene probe in polymer solution indicate the core of the micelle is nonpolar in nature. Also, the high value of the relative intensity of the NPN probe and the fluorescence anisotropy of the 1,6-diphenyl-1,3,5-hexatriene (DPH) probe indicated that the core of the micelle is highly viscous in nature. DLS was used to measure the average hydrodynamic radii and size distribution of the copolymer micelles. The copolymer with the longest PBA block had the poorest water solubility and consequently formed micelles with larger size while having a lower cmc. The "non-surface activity" was confirmed for cationic amphiphilic diblock copolymers in addition to anionic ones studied previously, indicating the universality of non-surface activity nature.
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Affiliation(s)
- Arjun Ghosh
- Department of Polymer Chemistry, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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Savarino P, Montoneri E, Bottigliengo S, Boffa V, Guizzetti T, Perrone DG, Mendichi R. Biosurfactants from Urban Wastes As Auxiliaries for Textile Dyeing. Ind Eng Chem Res 2009. [DOI: 10.1021/ie801853x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Piero Savarino
- Dipartimento di Chimica Generale e Chimica Organica, Università di Torino, C. M. D’Azeglio 48, 10125 Torino, Italy, and Istituto per lo Studio delle Macromolecole (CNR), Via E. Bassini 15, I-20133 Milano, Italy
| | - Enzo Montoneri
- Dipartimento di Chimica Generale e Chimica Organica, Università di Torino, C. M. D’Azeglio 48, 10125 Torino, Italy, and Istituto per lo Studio delle Macromolecole (CNR), Via E. Bassini 15, I-20133 Milano, Italy
| | - Stefano Bottigliengo
- Dipartimento di Chimica Generale e Chimica Organica, Università di Torino, C. M. D’Azeglio 48, 10125 Torino, Italy, and Istituto per lo Studio delle Macromolecole (CNR), Via E. Bassini 15, I-20133 Milano, Italy
| | - Vittorio Boffa
- Dipartimento di Chimica Generale e Chimica Organica, Università di Torino, C. M. D’Azeglio 48, 10125 Torino, Italy, and Istituto per lo Studio delle Macromolecole (CNR), Via E. Bassini 15, I-20133 Milano, Italy
| | - Tommaso Guizzetti
- Dipartimento di Chimica Generale e Chimica Organica, Università di Torino, C. M. D’Azeglio 48, 10125 Torino, Italy, and Istituto per lo Studio delle Macromolecole (CNR), Via E. Bassini 15, I-20133 Milano, Italy
| | - Daniele G. Perrone
- Dipartimento di Chimica Generale e Chimica Organica, Università di Torino, C. M. D’Azeglio 48, 10125 Torino, Italy, and Istituto per lo Studio delle Macromolecole (CNR), Via E. Bassini 15, I-20133 Milano, Italy
| | - Raniero Mendichi
- Dipartimento di Chimica Generale e Chimica Organica, Università di Torino, C. M. D’Azeglio 48, 10125 Torino, Italy, and Istituto per lo Studio delle Macromolecole (CNR), Via E. Bassini 15, I-20133 Milano, Italy
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Montoneri E, Boffa V, Savarino P, Perrone DG, Musso G, Mendichi R, Chierotti MR, Gobetto R. Biosurfactants from urban green waste. CHEMSUSCHEM 2009; 2:239-247. [PMID: 19229894 DOI: 10.1002/cssc.200800199] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
From waste came forth surfactants: Humic acid like substances isolated from 0-60 day-old compost display excellent surface activity and solvent properties. These biosurfactants were used to solubilize a dye in water below and above their critical micellar concentration. The biosurfactant unimers appear to have higher dye-solubilizing power than the corresponding micelles.Humic acid like substances isolated from compost show potential as chemical auxiliaries. In the present study, three surfactant samples were obtained from green waste composted for 0-60 days to assess aging effects of the source on the properties of the products. The surface activity, dye solubility enhancement, and chemical nature of these substances were compared. No differences in performance were established among the samples. They lower water surface tension and enhance the dye solubility upon increasing their concentration. However, the ratio of soluble dye to added surfactant is higher in the premicellar than in the postmicellar concentration region. Structural investigations indicated the humic acid like substances to be amphiphiles with molecular weights in the range of 1-3 x 10(5) g mol(-1). The surfactant samples were also compared to sodium dodecylbenzenesulfonate, polyacrylic acid, and soil and water humic substances. The results encourage the application of compost as a source of low-cost biosurfactant.
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Affiliation(s)
- Enzo Montoneri
- Dipartimento di Chimica Generale e Chimica Organica, Università di Torino, Corso Massimo d'Azeglio 48, Turin, Italy.
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12
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Zhao X, Pan F, Coffey P, Lu JR. Cationic copolymer-mediated DNA immobilization: interfacial structure and composition as determined by ellipsometry, dual polarization interferometry, and neutron reflection. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:13556-13564. [PMID: 18986183 DOI: 10.1021/la8024974] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
DNA immobilization onto support surfaces is required in biotechnological applications such as microarrays and gene delivery. This important interfacial molecular process can be mediated from a preadsobred cationic polymer. There is, however, a lack of understanding over the control of the interfacial composition and structural distribution of the DNA immobilized. We have used a combined approach of spectroscopic ellipsometry (SE), dual polarization interferometry (DPI) and neutron reflection (NR) to determine the interfacial polymer adsorption and the subsequent DNA binding. Cationic diblock copolymers incorporating 30 phosphorylcholine (PC) groups and different diethylaminoethyl groups, referred to as MPC30-DEAn, were chosen because of their well-defined molecular architecture. While our studies revealed different effects of surface charge and hydrophobicity, the amount of copolymers adsorbed on both model surfaces showed a broad trend of increase with solution pH, indicating a strong effect arising from pH-dependent charge density on the copolymers. In contrast, the copolymer structure and solution concentration showed a weak effect under the conditions studied. The subsequent DNA binding at pH 7 showed that on both surfaces the amount of DNA immobilized followed an approximate 1:1 charge interaction for all different DNA samples studied, irrespective of single or double strand, or different DNA size, indicating the dominant effect of electrostatic interaction between the two species. Both DPI and NR revealed consistent thickness increase upon DNA binding. Furthermore, with increasing DNA size, the interfacial layer became much thicker, and charge interaction drove more extensive interfacial mixing between the two species. Our results show that the amount of DNA immobilized is controlled by the amount of cationic copolymer preadsorbed that is in turn controlled by the solution pH and surface chemistry but that is barely affected by the type and concentration of DNA or cationic copolymer.
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Affiliation(s)
- XiuBo Zhao
- Biological Physics Group, School of Physics and Astronomy, The University of Manchester, Schuster Building, Manchester M13 9PL, UK
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Liu G, Wu D, Ma C, Zhang G, Wang H, Yang S. Insight into the Origin of the Thermosensitivity of Poly[2-(dimethylamino)ethyl methacrylate]. Chemphyschem 2007; 8:2254-9. [PMID: 17879258 DOI: 10.1002/cphc.200700464] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We investigate the effects of pH and temperature on the conformational changes of poly[2-(dimethylamino)ethyl methacrylate] (PDEM) chains at the air/water interface by using Langmuir balance and sum frequency generation vibrational spectroscopy. At pH 4, the tertiary amine groups are fully charged and the PDEM chains are so hydrophilic that they completely enter into the water phase and do not exhibit thermosensitivity. At pH 7, these groups are only partially charged, and the accompanying hydration/dehydration--followed by repartitioning into the water and air phases--gives rise to a marked thermosensitivty. Finally, at pH 10, the tertiary amine groups become uncharged and thus preferentially stay in the hydrophobic air phase, devoid of associated water molecules, which results in the surface-pressure change (DeltaPi) being nearly independent of the temperature. Our Langmuir-balance experiments, coupled with surface-sensitive spectroscopy, demonstrate that: 1) the thermosensitivity of the PDEM chains relates to the hydration/dehydration of the tertiary amine groups, 2) the phase transition of thermosensitive polymers is most likely initiated by the dehydration of the chains, and 3) the phase transition of thermosensitive polymers at the air/water interface is markedly different from that in aqueous solution because of the redistribution of the macromolecular segments induced by the asymmetric forces at the air/water interface.
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Affiliation(s)
- Guangming Liu
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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14
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Zhao X, Zhang Z, Pan F, Ma Y, Armes SP, Lewis AL, Lu JR. Solution pH-regulated interfacial adsorption of diblock phosphorylcholine copolymers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:9597-603. [PMID: 16207041 DOI: 10.1021/la0514359] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Spectroscopic ellipsometry has been used to examine the pH-responsive interfacial adsorption of a series of biocompatible diblock copolymers incorporating 2-methacryloyloxyethyl phosphorylcholine-based (MPC) residues and 2-(dialkylamino)ethyl methacrylate residues, with a specific focus on 2-(diethylamino)ethyl groups (referred to as MPCm-DEAn, where m and n refer to the mean degrees of polymerization of each block) at the hydrophilic silicon oxide/water interface. For all the copolymers studied the surface excess shows only weak concentration dependence. Increasing the length of the DEA block has little effect on the dynamic or equilibrated adsorption at pH 7, indicating that the DEA block adopts a flat conformation on the silicon oxide surface at this pH. With increasing pH, however, the surface excess shows a dramatic increase, followed by a subsequent decline. The observed maximum in surface excess represents a balance between charge over-compensation of the copolymer with the oppositely charged surface and the subsequently reduced charge density of the copolymer. Variations in the observed maxima for various MPCm-DEAn diblock copolymers indicate different surface conformations at high pH. Salt addition does not affect copolymer adsorption. This behavior is attractive for biomedical applications in which the ionic strength is variable. It was also found that the preadsorbed diblock copolymers immobilized DNA from solution to an extent that is proportional to the relative charge ratio between the anionic DNA and the cationic DEA block of the copolymer.
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Affiliation(s)
- Xiubo Zhao
- Biological Physics Group, School of Physics and Astronomy, The University of Manchester, Sackville Street Building, Sackville Street, Manchester M60 1QD, U.K
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Kaewsaiha P, Matsumoto K, Matsuoka H. Synthesis and nanostructure of strong polyelectrolyte brushes in amphiphilic diblock copolymer monolayers on a water surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:6754-6761. [PMID: 15274582 DOI: 10.1021/la0491145] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We synthesized an ionic amphiphilic diblock copolymer, poly(hydrogenated isoprene)-b-poly(styrenesulfonic acid) (PIp-h2-b-PSS), by living anionic polymerization, and the nanostructure of its monolayer spread on a water surface was directly investigated by the in situ X-ray reflectivity technique. The monolayer of the diblock copolymer on a water surface had a smooth hydrophobic PIp-h2 layer on water and a "carpet"/polymer brush double layer in a hydrophilic sodium polystyrene sulfonate (PSSNa) layer under the water. The surface pressure dependence and PSSNa chain length dependence of the PIp-h2 layer thickness and the brush nanostructure were quantitatively studied. The effect of salt concentration in the subphase was also investigated in aqueous solutions containing 0-2 M NaCl. The salt effect on monolayer structure occurred at around 0.2 M. The thickness of the PSS brush layer decreased at salt concentrations above 0.2 M, while no structural change was observed below 0.2 M. This critical salt concentration is thought to be related to the balance of ionic concentrations inside the brush and in bulk solution.
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Affiliation(s)
- Ploysai Kaewsaiha
- Department of Polymer Chemistry, Kyoto University, Kyoto 615-8510, Japan
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Mouri E, Matsumoto K, Matsuoka H. Carpetlike dense-layer formation in a polyelectrolyte brush at the air/water interface. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/polb.10561] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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17
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Vieira JB, Li ZX, Thomas RK, Penfold J. Structure of Triblock Copolymers of Ethylene Oxide and Propylene Oxide at the Air/Water Interface Determined by Neutron Reflection. J Phys Chem B 2002. [DOI: 10.1021/jp013851h] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J. B. Vieira
- Physical Chemistry Laboratory, South Parks Road, Oxford, OX1 3QZ, United Kingdom
| | - Z. X. Li
- Physical Chemistry Laboratory, South Parks Road, Oxford, OX1 3QZ, United Kingdom
| | - R. K. Thomas
- Physical Chemistry Laboratory, South Parks Road, Oxford, OX1 3QZ, United Kingdom
| | - J. Penfold
- ISIS, CLRC, Chilton, Didcot, Oxfordshire, OX11 0QX, United Kingdom
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18
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Matsumoto K, Mizuno U, Matsuoka H, Yamaoka H. Synthesis of Novel Silicon-Containing Amphiphilic Diblock Copolymers and Their Self-Assembly Formation in Solution and at Air/Water Interface. Macromolecules 2001. [DOI: 10.1021/ma011254n] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kozo Matsumoto
- Department of Polymer Chemistry, Kyoto University, Kyoto 606-8501, Japan
| | - Utako Mizuno
- Department of Polymer Chemistry, Kyoto University, Kyoto 606-8501, Japan
| | - Hideki Matsuoka
- Department of Polymer Chemistry, Kyoto University, Kyoto 606-8501, Japan
| | - Hitoshi Yamaoka
- Department of Polymer Chemistry, Kyoto University, Kyoto 606-8501, Japan
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19
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Bütün V, Armes S, Billingham N. Synthesis and aqueous solution properties of near-monodisperse tertiary amine methacrylate homopolymers and diblock copolymers. POLYMER 2001. [DOI: 10.1016/s0032-3861(01)00066-0] [Citation(s) in RCA: 532] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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20
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de Paz Báñez M, Robinson K, Vamvakaki M, Lascelles S, Armes S. Synthesis of novel cationic polymeric surfactants. POLYMER 2000. [DOI: 10.1016/s0032-3861(00)00217-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Nakano M, Deguchi M, Endo H, Matsumoto K, Matsuoka H, Yamaoka H. Self-Assembly of Poly(1,1-diethylsilabutane)-block-poly(2-hydroxyethyl methacrylate) Block Copolymer. 2. Monolayer at the Air−Water Interface. Macromolecules 1999. [DOI: 10.1021/ma9819788] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Minoru Nakano
- Department of Polymer Chemistry, Kyoto University, Kyoto 606-8501, Japan
| | - Masaki Deguchi
- Department of Polymer Chemistry, Kyoto University, Kyoto 606-8501, Japan
| | - Hitoshi Endo
- Department of Polymer Chemistry, Kyoto University, Kyoto 606-8501, Japan
| | - Kozo Matsumoto
- Department of Polymer Chemistry, Kyoto University, Kyoto 606-8501, Japan
| | - Hideki Matsuoka
- Department of Polymer Chemistry, Kyoto University, Kyoto 606-8501, Japan
| | - Hitoshi Yamaoka
- Department of Polymer Chemistry, Kyoto University, Kyoto 606-8501, Japan
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22
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Pinto JR, Novak SW, Nicholas M. Aqueous Dye Diffusion in Thin Films of Water-Soluble Poly(Vinyl Pyrrolidone) Copolymers: A Dynamic Secondary Ion Mass Spectrometry Study. J Phys Chem B 1999. [DOI: 10.1021/jp9911292] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jerry R. Pinto
- International Specialty Products, Wayne, New Jersey 07470
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23
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Webster J, Langridge S. Applications of index matching in reflectometry, SANS and Brewster angle microscopy. Curr Opin Colloid Interface Sci 1999. [DOI: 10.1016/s1359-0294(99)00040-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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24
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Lowe AB, Billingham NC, Armes SP. Synthesis and Properties of Low-Polydispersity Poly(sulfopropylbetaine)s and Their Block Copolymers. Macromolecules 1999. [DOI: 10.1021/ma980543h] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andrew B. Lowe
- School of Chemistry, Physics and Environmental Science, University of Sussex, Brighton, BN1 9QJ, UK
| | - Norman C. Billingham
- School of Chemistry, Physics and Environmental Science, University of Sussex, Brighton, BN1 9QJ, UK
| | - Steven P. Armes
- School of Chemistry, Physics and Environmental Science, University of Sussex, Brighton, BN1 9QJ, UK
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25
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R. Lu J. Chapter 2. Neutron reflection study of globular protein adsorption at planar interfaces. ACTA ACUST UNITED AC 1999. [DOI: 10.1039/pc095003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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