51
|
Zhu PW, Chen L. Synergistic Effects of Bound Micelles and Temperature on the Flexibility of Thermoresponsive Polymer Brushes. J Phys Chem B 2016; 120:11595-11606. [PMID: 27750008 DOI: 10.1021/acs.jpcb.6b08696] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The persistence length is a key parameter for the quantitative interpretation of the flexibility of polymers. We have studied complexes composed of a spherical poly(N-isopropylacrylamide) (PNIPAM) brush and a sodium dodecyl sulfate micelle in an effort to characterize the flexibility of tethered PNIPAM below the lower critical solution temperature TLCST. An analytical mean-field model is used to describe the persistence length Lp in a broad range of ψ, the number of bound micelles per chain. The persistence length of micelle-constrained PNIPAM is quantitatively correlated with the thermal energy kBT, electrostatic repulsion fC, and effective excluded-volume parameter νeff. The persistence length per ψ, which depends on T and fC, is found to scale with a synergistic effect fC/(ψkBT). The results reveal that the bound-micelle charges affecting the persistence length are analogous to the fixed charges of polyelectrolytes, though the bound micelles are separated by a large number of neutral monomers. The extension ⟨L⟩ of micelle-constrained PNIPAM decreases as ⟨L⟩ ∼ fC-βF with fC, where βF ≈ 0.58-0.8 depending on ψ, but as the universal power law ⟨L⟩ ∼ (fC/kBT)-0.6 with the synergistic effect fC/(kBT), irrespective of ψ. In spite of the intricate interplay among the multiple components in the system, the extension scales as a function of νeff as ⟨L⟩ ∼ (νeff/ψLp)-βV, where βV ≈ 0.35 for the significant monomer interaction and βV ≈ 0.2 for the weak or negligible monomer interaction.
Collapse
Affiliation(s)
- Peng-Wei Zhu
- Department of Materials Science and Engineering and ‡Department of Chemical Engineering, Monash University , Clayton, VIC 3800, Australia
| | - Luguang Chen
- Department of Materials Science and Engineering and ‡Department of Chemical Engineering, Monash University , Clayton, VIC 3800, Australia
| |
Collapse
|
52
|
|
53
|
Murdoch TJ, Humphreys BA, Willott JD, Gregory KP, Prescott SW, Nelson A, Wanless EJ, Webber GB. Specific Anion Effects on the Internal Structure of a Poly(N-isopropylacrylamide) Brush. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b01001] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Timothy J. Murdoch
- Priority
Research Centre for Advanced Particle Processing and Transport, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Ben A. Humphreys
- Priority
Research Centre for Advanced Particle Processing and Transport, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Joshua D. Willott
- Priority
Research Centre for Advanced Particle Processing and Transport, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Kasimir P. Gregory
- Priority
Research Centre for Advanced Particle Processing and Transport, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Stuart W. Prescott
- School
of Chemical Engineering, UNSW Australia, UNSW Sydney, NSW 2052, Australia
| | - Andrew Nelson
- Australian Nuclear
Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
| | - Erica J. Wanless
- Priority
Research Centre for Advanced Particle Processing and Transport, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Grant B. Webber
- Priority
Research Centre for Advanced Particle Processing and Transport, University of Newcastle, Callaghan, NSW 2308, Australia
| |
Collapse
|
54
|
Seuss M, Schmolke W, Drechsler A, Fery A, Seiffert S. Core-Shell Microgels with Switchable Elasticity at Constant Interfacial Interaction. ACS APPLIED MATERIALS & INTERFACES 2016; 8:16317-16327. [PMID: 27276500 DOI: 10.1021/acsami.6b04339] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Hydrogels based on poly(N-isopropylacrylamide) (pNIPAAm) exhibit a thermo-reversible volume phase transition from swollen to deswollen states. This change of the hydrogel volume is accompanied by changes of the hydrogel elastic and Young's moduli and of the hydrogel interfacial interactions. To decouple these parameters from one another, we present a class of submillimeter sized hydrogel particles that consist of a thermosensitive pNIPAAm core wrapped by a nonthermosensitive polyacrylamide (pAAm) shell, each templated by droplet-based microfluidics. When the microgel core deswells upon increase of the temperature to above 34 °C, the shell is stretched and dragged to follow this deswelling into the microgel interior, resulting in an increase of the microgel surficial Young's modulus. However, as the surface interactions of the pAAm shell are independent of temperature at around 34 °C, they do not considerably change during the pNIPAAm-core volume phase transition. This feature makes these core-shell microgels a promising platform to be used as building blocks to assemble soft materials with rationally and independently tunable mechanics.
Collapse
Affiliation(s)
- Maximilian Seuss
- Leibniz-Institut für Polymerforschung Dresden e.V. , Institute of Physical Chemistry and Polymer Physics, Hohe Str. 6, D-01069 Dresden, Germany
| | - Willi Schmolke
- Institute of Physical Chemistry, Johannes Gutenberg-Universität Mainz , Duesbergweg 10-14, D-55128 Mainz, Germany
| | - Astrid Drechsler
- Leibniz-Institut für Polymerforschung Dresden e.V. , Institute of Physical Chemistry and Polymer Physics, Hohe Str. 6, D-01069 Dresden, Germany
| | - Andreas Fery
- Leibniz-Institut für Polymerforschung Dresden e.V. , Institute of Physical Chemistry and Polymer Physics, Hohe Str. 6, D-01069 Dresden, Germany
- Department of Physical Chemistry of Polymeric Materials, Technische Universität Dresden , Hohe Str. 6, D-01069 Dresden, Germany
| | - Sebastian Seiffert
- Institute of Physical Chemistry, Johannes Gutenberg-Universität Mainz , Duesbergweg 10-14, D-55128 Mainz, Germany
| |
Collapse
|
55
|
Desseaux S, Hinestrosa JP, Schüwer N, Lokitz BS, Ankner JF, Kilbey SM, Voitchovsky K, Klok HA. Swelling Behavior and Nanomechanical Properties of (Peptide-Modified) Poly(2-hydroxyethyl methacrylate) and Poly(poly(ethylene glycol) methacrylate) Brushes. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b00881] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Solenne Desseaux
- Institut
des Matériaux et Institut des Sciences et Ingénierie
Chimiques, Laboratoire des Polymères, École Polytechnique Fédérale de Lausanne (EPFL), Bâtiment MXD, Station 12, CH-1015 Lausanne, Switzerland
| | - Juan Pablo Hinestrosa
- Institut
des Matériaux et Institut des Sciences et Ingénierie
Chimiques, Laboratoire des Polymères, École Polytechnique Fédérale de Lausanne (EPFL), Bâtiment MXD, Station 12, CH-1015 Lausanne, Switzerland
| | - Nicolas Schüwer
- Institut
des Matériaux et Institut des Sciences et Ingénierie
Chimiques, Laboratoire des Polymères, École Polytechnique Fédérale de Lausanne (EPFL), Bâtiment MXD, Station 12, CH-1015 Lausanne, Switzerland
| | | | | | - S. Michael Kilbey
- Departments of Chemistry and Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996-1600, United States
| | - Kislon Voitchovsky
- Department
of Physics, Durham University, South Road, Durham DH1 3LE, U.K
| | - Harm-Anton Klok
- Institut
des Matériaux et Institut des Sciences et Ingénierie
Chimiques, Laboratoire des Polymères, École Polytechnique Fédérale de Lausanne (EPFL), Bâtiment MXD, Station 12, CH-1015 Lausanne, Switzerland
| |
Collapse
|
56
|
Zhuang P, Dirani A, Glinel K, Jonas AM. Temperature Dependence of the Surface and Volume Hydrophilicity of Hydrophilic Polymer Brushes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:3433-3444. [PMID: 27003634 DOI: 10.1021/acs.langmuir.6b00448] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The temperature-dependence of the volume and surface hydrophilicity of a series of water-swollen dense polymer brushes is measured by contact angle measurements in the captive bubble configuration, by ellipsometry, and by quartz crystal microbalance with dissipation monitoring (QCM-D). Thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) and poly(di(methoxyethoxy)ethyl methacrylate) (PMEO2MA), strongly hydrophilic poly(N,N-dimethylacrylamide) (PDMA) and poly(oligo(ethylene glycol) methacrylate) (POEGMA), and weakly hydrophilic poly(2-hydroxyethyl methacrylate) (PHEMA) brushes were synthesized by surface-initiated atom-transfer radical polymerization (SI-ATRP). Conditions leading to reproducible measurements of the contact angle are first provided, giving access to the surface hydrophilicity. Volume hydrophilicity is quantified by measuring the swelling of the brushes, either by QCM-D or by ellipsometry. A model-free methodology is proposed to analyze the QCM-D data. Comparison between the acoustic and optical swelling coefficients shows that QCM-D is sensitive to the maximal thickness of swollen brushes, while ellipsometry provides an integral thickness. Diagrams of surface versus volume hydrophilicity of the brushes finally lead to identify two types of behavior: strongly water-swollen brushes exhibit a progressive decrease of volume hydrophilicity with temperature, while surface hydrophilicity changes moderately; weakly water-swollen brushes have a close-to-constant volume hydrophilicity, while surface hydrophilicity decreases with temperature. Thermoresponsive brushes abruptly switch from one behavior to the other, and do not exhibit an abrupt change of surface hydrophilicity across their collapse transition contrarily to a common erroneous belief. In general, there is no direct correlation between surface and volume hydrophilicity, because surface properties are dependent on the details of conformation and composition at the surface, whereas volume properties are averaged over a finite region within the brush.
Collapse
Affiliation(s)
- Pengyu Zhuang
- Bio & Soft Matter, Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain , Croix du Sud 1/L7.04.02, 1348 Louvain-la-Neuve, Belgium
| | - Ali Dirani
- Bio & Soft Matter, Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain , Croix du Sud 1/L7.04.02, 1348 Louvain-la-Neuve, Belgium
| | - Karine Glinel
- Bio & Soft Matter, Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain , Croix du Sud 1/L7.04.02, 1348 Louvain-la-Neuve, Belgium
| | - Alain M Jonas
- Bio & Soft Matter, Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain , Croix du Sud 1/L7.04.02, 1348 Louvain-la-Neuve, Belgium
| |
Collapse
|
57
|
Varma S, Bureau L, Débarre D. The Conformation of Thermoresponsive Polymer Brushes Probed by Optical Reflectivity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:3152-3163. [PMID: 26986181 DOI: 10.1021/acs.langmuir.6b00138] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We describe a microscope-based optical setup that allows us to perform space- and time-resolved measurements of the spectral reflectance of transparent substrates coated with ultrathin films. This technique is applied to investigate the behavior in water of thermosensitive polymer brushes made of poly(N-isopropylacrylamide) grafted on glass. We show that spectral reflectance measurements yield quantitative information about the conformation and axial structure of the brushes as a function of temperature. We study how parameters such as grafting density and chain length affect the hydration state of a brush, and provide one of the few experimental evidences for the occurrence of vertical phase separation in the vicinity of the lower critical solution temperature of the polymer. The origin of the hysteretic behavior of poly(N-isopropylacrylamide) brushes upon cycling the temperature is also clarified. We thus demonstrate that our optical technique allows for in-depth characterization of stimuli-responsive polymer layers, which is crucial for the rational design of smart polymer coatings in actuation, gating, or sensing applications.
Collapse
Affiliation(s)
- Siddhartha Varma
- University Grenoble Alpes, LIPHY, F-38000 Grenoble, France
- CNRS, LIPHY, F-38000 Grenoble, France
| | - Lionel Bureau
- University Grenoble Alpes, LIPHY, F-38000 Grenoble, France
- CNRS, LIPHY, F-38000 Grenoble, France
| | - Delphine Débarre
- University Grenoble Alpes, LIPHY, F-38000 Grenoble, France
- CNRS, LIPHY, F-38000 Grenoble, France
| |
Collapse
|
58
|
Appel J, Fölker B, Sprakel J. Mechanics at the glass-to-gel transition of thermoresponsive microgel suspensions. SOFT MATTER 2016; 12:2515-2522. [PMID: 26843322 DOI: 10.1039/c5sm02940f] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We study the rheology of systems of thermoresponsive microgels which can transition between a repulsive glass and an attractive gel state. We find marked differences between these two colloidal solids, within the same experimental system, due to the different origins for their dynamic arrest. While the rigidity of the repulsive systems depends solely on particle volume fraction, we find that the change in linear elasticity upon introducing attractive bonds in the system scales linearly with the adhesive bond strength which can be tuned with the temperature in our experiments. And while the glasses yield reversibly and with a rate-dependent energy dissipation, bond-reorganisation in the gels is suppressed so that their rupture is irreversible and accompanied by a high, but rate-independent, dissipation. These results highlight how colloids with responsive interactions can be employed to shed new light onto solid-solid transitions.
Collapse
Affiliation(s)
- Jeroen Appel
- Physical Chemistry and Soft Matter, Wageningen University, Dreijenplein 6, 6703 HB, Wageningen, The Netherlands.
| | - Bart Fölker
- Physical Chemistry and Soft Matter, Wageningen University, Dreijenplein 6, 6703 HB, Wageningen, The Netherlands.
| | - Joris Sprakel
- Physical Chemistry and Soft Matter, Wageningen University, Dreijenplein 6, 6703 HB, Wageningen, The Netherlands.
| |
Collapse
|
59
|
De Mets R, Hennig K, Bureau L, Balland M. Fast and robust fabrication of reusable molds for hydrogel micro-patterning. Biomater Sci 2016; 4:1630-1637. [DOI: 10.1039/c6bm00364h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present a method to create protein micropatterns onto polyacrylamide hydrogels, in order to control the adhesive confinement of cells in traction force microscopy experiments. The technique is based on patterned polymer brushes that serve as molds that can be re-used without repeating microfabrication steps.
Collapse
|
60
|
Wang Q, Liu L, Wang Y, Liu P, Jiang H, Xu Z, Ma Z, Oren S, Chow EKC, Lu M, Dong L. Tunable Optical Nanoantennas Incorporating Bowtie Nanoantenna Arrays with Stimuli-Responsive Polymer. Sci Rep 2015; 5:18567. [PMID: 26681478 PMCID: PMC4683518 DOI: 10.1038/srep18567] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/20/2015] [Indexed: 02/06/2023] Open
Abstract
We report on a temperature-responsive tunable plasmonic device that incorporates coupled bowtie nanoantenna arrays (BNAs) with a submicron-thick, thermosensitive hydrogel coating. The coupled plasmonic nanoparticles provide an intrinsically higher field enhancement than conventional individual nanoparticles. The favorable scaling of plasmonic dimers at the nanometer scale and ionic diffusion at the submicron scale is leveraged to achieve strong optical resonance and rapid hydrogel response, respectively. We demonstrate that the hydrogel-coated BNAs are able to sense environmental temperature variations. The phase transition of hydrogel leads to 16.2 nm of resonant wavelength shift for the hydrogel-coated BNAs, whereas only 3 nm for the uncoated counterpart. The response time of the device to temperature variations is only 250 ms, due to the small hydrogel thickness at the submicron scale. The demonstration of the ability of the device to tune its optical resonance in response to an environmental stimulus (here, temperature) suggests a possibility of making many other tunable plasmonic devices through the incorporation of coupled plasmonic nanostructures and various environmental-responsive hydrogels.
Collapse
Affiliation(s)
- Qiugu Wang
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA
| | - Longju Liu
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA
| | - Yifei Wang
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA
| | - Peng Liu
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA
| | - Huawei Jiang
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA
| | - Zhen Xu
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA
| | - Zhuo Ma
- Department of Aerospace Engineering, Iowa State University, Ames, Iowa 50011, USA
| | - Seval Oren
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA
| | - Edmond K. C. Chow
- Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Meng Lu
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA
- Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011, USA
| | - Liang Dong
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA
| |
Collapse
|
61
|
Nguyen M, Kanaev A, Sun X, Lacaze E, Lau-Truong S, Lamouri A, Aubard J, Felidj N, Mangeney C. Tunable Electromagnetic Coupling in Plasmonic Nanostructures Mediated by Thermoresponsive Polymer Brushes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:12830-7. [PMID: 26550681 DOI: 10.1021/acs.langmuir.5b03339] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A smart and highly SERS-active plasmonic platform was designed by coupling regular arrays of nanotriangles to colloidal gold nanorods via a thermoresponsive polymer spacer (poly(N-isopropylacrylamide), PNIPAM). The substrates were prepared by combining a top-down and a bottom-up approach based on nanosphere lithography, surface-initiated controlled radical polymerization, and colloidal assembly. This multistep strategy provided regular hexagonal arrays of nanotriangles functionalized by polymer brushes and colloidal gold nanorods, confined exclusively on the nanotriangle surface. Interestingly, one could finely tune the gold nanorod impregnation on the polymer-coated nanostructures by adjusting the polymer layer thickness, leading to highly coupled plasmonic systems for intense SERS signal. Moreover, the thermoresponsive properties of the PNIPAM brushes could be wisely handled in order to monitor the SERS activity of the nanostructures coupled via this polymer spacer. The coupled hybrid plasmonic nanostructures designed in this work are therefore very promising smart platforms for the sensitive detection of analytes by SERS.
Collapse
Affiliation(s)
- Mai Nguyen
- Sorbonne Paris Cité, ITODYS, UMR 7086, CNRS, Université Paris Diderot , 15 rue Jean Antoine de Baïf, 75205 Paris, Cedex 13, France
| | - Andrei Kanaev
- Laboratoire des Sciences des Procédés et des Matériaux, Université Paris13 , 93430 Villetaneuse, France
| | - Xiaonan Sun
- Sorbonne Paris Cité, ITODYS, UMR 7086, CNRS, Université Paris Diderot , 15 rue Jean Antoine de Baïf, 75205 Paris, Cedex 13, France
| | - Emmanuelle Lacaze
- UPMC Univ Paris 06, CNRS-UMR 7588, Institut des NanoSciences de Paris, Sorbonne Universités , F-75005 Paris, France
| | - Stéphanie Lau-Truong
- Sorbonne Paris Cité, ITODYS, UMR 7086, CNRS, Université Paris Diderot , 15 rue Jean Antoine de Baïf, 75205 Paris, Cedex 13, France
| | - Aazdine Lamouri
- Sorbonne Paris Cité, ITODYS, UMR 7086, CNRS, Université Paris Diderot , 15 rue Jean Antoine de Baïf, 75205 Paris, Cedex 13, France
| | - Jean Aubard
- Sorbonne Paris Cité, ITODYS, UMR 7086, CNRS, Université Paris Diderot , 15 rue Jean Antoine de Baïf, 75205 Paris, Cedex 13, France
| | - Nordin Felidj
- Sorbonne Paris Cité, ITODYS, UMR 7086, CNRS, Université Paris Diderot , 15 rue Jean Antoine de Baïf, 75205 Paris, Cedex 13, France
| | - Claire Mangeney
- Sorbonne Paris Cité, ITODYS, UMR 7086, CNRS, Université Paris Diderot , 15 rue Jean Antoine de Baïf, 75205 Paris, Cedex 13, France
| |
Collapse
|
62
|
Yu Y, Kieviet BD, Liu F, Siretanu I, Kutnyánszky E, Vancso GJ, de Beer S. Stretching of collapsed polymers causes an enhanced dissipative response of PNIPAM brushes near their LCST. SOFT MATTER 2015; 11:8508-16. [PMID: 26371862 DOI: 10.1039/c5sm01426c] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Poly(N-isopropyl acrylamide) (PNIPAM) is a stimulus-responsive polymer that can switch in water from an expanded state below the lower critical solution temperature (LCST) of 32 °C to a globular state above the LCST. It was recently shown that, as a consequence of this conformational transition, the interfacial and (tribo-)mechanical properties of polymeric systems composed of PNIPAM can be switched between two states. Here we show that the tribo-mechanical properties of a particular type of PNIPAM system, which is the PNIPAM brush, do not just change between two states, but instead evolve continuously and non-monotonically upon increasing/decreasing temperature. To do so, we present atomic force microscopy experiments in which we measure the adhesion hysteresis and the friction upon bringing a gold colloid in relative motion with PNIPAM brushes at temperatures around the LCST. Both the friction and the adhesion hysteresis display a pronounced maximum exactly at the LCST. The force vs. distance data captured at these temperatures show a long-ranged adhesive interaction upon moving the colloid away from the original point of contact, which indicates that during this retraction the partly collapsed polymers in the brush become strongly stretched.
Collapse
Affiliation(s)
- Yunlong Yu
- Materials Science and Technology of Polymers, MESA + Institute of Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
| | - Bernard D Kieviet
- Materials Science and Technology of Polymers, MESA + Institute of Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
| | - Fei Liu
- Physics of Complex Fluids, MESA + Institute of Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Igor Siretanu
- Physics of Complex Fluids, MESA + Institute of Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Edit Kutnyánszky
- Materials Science and Technology of Polymers, MESA + Institute of Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
| | - G Julius Vancso
- Materials Science and Technology of Polymers, MESA + Institute of Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
| | - Sissi de Beer
- Materials Science and Technology of Polymers, MESA + Institute of Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
| |
Collapse
|
63
|
Cimen D, Yildirim E, Caykara T. Synthesis of dual-functional poly(6-azidohexylmethacrylate) brushes by a RAFT agent carrying carboxylic acid end groups. ACTA ACUST UNITED AC 2015. [DOI: 10.1002/pola.27613] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Dilek Cimen
- Department of Chemistry; Faculty of Science; Gazi University; 06500 Besevler Ankara Turkey
| | - Ertan Yildirim
- Department of Chemistry; Faculty of Science; Gazi University; 06500 Besevler Ankara Turkey
| | - Tuncer Caykara
- Department of Chemistry; Faculty of Science; Gazi University; 06500 Besevler Ankara Turkey
| |
Collapse
|
64
|
Gambinossi F, Sefcik LS, Wischerhoff E, Laschewsky A, Ferri JK. Engineering adhesion to thermoresponsive substrates: effect of polymer composition on liquid-liquid-solid wetting. ACS APPLIED MATERIALS & INTERFACES 2015; 7:2518-2528. [PMID: 25569588 DOI: 10.1021/am507418m] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Adhesion control in liquid-liquid-solid systems represents a challenge for applications ranging from self-cleaning to biocompatibility of engineered materials. By using responsive polymer chemistry and molecular self-assembly, adhesion at solid/liquid interfaces can be achieved and modulated by external stimuli. Here, we utilize thermosensitive polymeric materials based on random copolymers of di(ethylene glycol) methyl ether methacrylate (x = MEO2MA) and oligo(ethylene glycol) methyl ether methacrylate (y = OEGMA), that is, P(MEO2MAx-co-OEGMAy), to investigate the role of hydrophobicity on the phenomenon of adhesion. The copolymer ratio (x/y) dictates macromolecular changes enabling control of the hydrophilic-to-lipophilic balance (HBL) of the polymer brushes through external triggers such as ionic strength and temperature. We discuss the HBL of the thermobrushes in terms of the surface energy of the substrate by measuring the contact angle at water-decane-P(MEO2MAx-co-OEGMAy) brush contact line as a function of polymer composition and temperature. Solid supported polyelectrolyte layers grafted with P(MEO2MAx-co-OEGMAy) display a transition in the wettability that is related to the lower critical solution temperature of the polymer brushes. Using experimental observation of the hydrophilic to hydrophobic transition by the contact angle, we extract the underlying energetics associated with liquid-liquid-solid adhesion as a function of the copolymer ratio. The change in cellular attachment on P(MEO2MAx-co-OEGMAy) substrates of variable (x/y) composition demonstrates the subtle role of compositional tuning on the ability to control liquid-liquid-solid adhesion in biological applications.
Collapse
Affiliation(s)
- Filippo Gambinossi
- Department of Chemical and Biomolecular Engineering, Lafayette College , 740 High Street, Easton18042, Pennsylvania, United States
| | | | | | | | | |
Collapse
|
65
|
Yu Y, Kieviet BD, Kutnyanszky E, Vancso GJ, de Beer S. Cosolvency-Induced Switching of the Adhesion between Poly(methyl methacrylate) Brushes. ACS Macro Lett 2015; 4:75-79. [PMID: 35596376 DOI: 10.1021/mz500775w] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
We present a simple method to reversibly switch the adhesive force between two surfaces that are decorated with poly(methyl methacrylate) (PMMA) graft polymers. By employment of a PMMA/isopropanol/water or a PMMA/ethanol/water cosolvent system, we can tune the swelling of the brushes. In pure isopropanol or ethanol the polymer grafts are collapsed, and the adhesion is high when the contacting brushes are pulled apart. In an 80-20 vol % isopropanol-water or ethanol-water composition, the brushes are swollen. In these systems the adhesion is approximately 5 times smaller compared to the adhesion measured in the pure solvent systems. Moreover, we show that PMMA/isopropanol/water cosolvent systems perform better as switchable adhesives than PMMA/ethanol/water cosolvent systems. In the latter pulling events can arise when the swollen brushes are kept in contact for a longer time, such that the adhesion hysteresis can become large and the surface coating can be damaged due to bond-breaking events.
Collapse
Affiliation(s)
- Yunlong Yu
- Materials
Science and Technology
of Polymers, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Bernard D. Kieviet
- Materials
Science and Technology
of Polymers, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Edit Kutnyanszky
- Materials
Science and Technology
of Polymers, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - G. Julius Vancso
- Materials
Science and Technology
of Polymers, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Sissi de Beer
- Materials
Science and Technology
of Polymers, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| |
Collapse
|
66
|
Zhu PW. Effects of Sodium Dodecyl Sulfate on Structures of Poly(N-isopropylacrylamide) at the Particle Surface. J Phys Chem B 2014; 119:359-71. [DOI: 10.1021/jp510350w] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Peng Wei Zhu
- Department of Materials Engineering, Monash University, Clayton, VIC 3800, Australia
| |
Collapse
|
67
|
Li JJ, Zhou YN, Luo ZH. Thermo-responsive brush copolymers with structure-tunable LCST and switchable surface wettability. POLYMER 2014. [DOI: 10.1016/j.polymer.2014.10.025] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
68
|
Krishnamoorthy M, Hakobyan S, Ramstedt M, Gautrot JE. Surface-initiated polymer brushes in the biomedical field: applications in membrane science, biosensing, cell culture, regenerative medicine and antibacterial coatings. Chem Rev 2014; 114:10976-1026. [PMID: 25353708 DOI: 10.1021/cr500252u] [Citation(s) in RCA: 393] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Mahentha Krishnamoorthy
- Institute of Bioengineering and ‡School of Engineering and Materials Science, Queen Mary University of London , Mile End Road, London E1 4NS, United Kingdom
| | | | | | | |
Collapse
|
69
|
Bhairamadgi NS, Pujari SP, van Rijn CJM, Zuilhof H. Adhesion and friction properties of fluoropolymer brushes: on the tribological inertness of fluorine. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:12532-12540. [PMID: 25313839 DOI: 10.1021/la501802b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The effects of fluorination on the adhesion and friction properties of covalently bound poly(fluoroalkyl methacrylate) polymer brushes (thickness ∼80 nm) were systematically investigated. Si(111) surfaces were functionalized with a covalently bound initiator via a thiol-yne click reaction to have a high surface coverage for initiator immobilization. Surface-initiated atom-transfer radical polymerization (SI-ATRP) was employed for the synthesis of four different fluoropolymer brushes (SPFx, where x = 0, 3, 7, or 17 F atoms per monomer), based on fluoroalkyl methacrylates. All polymer brushes were characterized with static contact angle measurements, X-ray photoelectron spectroscopy (XPS), and infrared absorption reflection spectroscopy (IRRAS). The polymer brushes exhibited an excellent hydrophobicity, with static water contact angles of up to 121° depending on the number of fluorine atoms per side chain in fluoroalkyl methacrylate. The degree of swelling was precisely studied by using ellipsometry in different solvents such as acetone, hexadecane, hexafluoroisopropanol, nonafluorobutyl methyl ether, and Fluorinert FC-40. The polymer brushes have shown nanoscale swelling behavior in all solvents except hexadecane. The grafting density decreased upon increasing fluorine content in polymer brushes from 0.65 chains/nm(2) (SPF0) to 0.10 chains/nm(2) (SPF17) as observed in Fluorinert FC-40 as a good solvent. Adhesion and friction force measurements were conducted with silica colloidal probe atomic force microscopy (CP-AFM) under ambient, dry (argon), and lubricating fluid conditions. SPF17 showed the lowest coefficient of friction 0.005 under ambient condition (RH = 44 ± 2%) and a further decrease with 50% under fluidic conditions. These polymer brushes also showed adhesion forces as low as 6.9 nN under ambient conditions, which further went down to 0.003 nN under fluidic conditions (Fluorinert FC-40 and hexadecane) at 10 nN force.
Collapse
Affiliation(s)
- Nagendra S Bhairamadgi
- Laboratory of Organic Chemistry, Wageningen University , Dreijenplein 8, 6703HB, Wageningen, The Netherlands
| | | | | | | |
Collapse
|
70
|
Solvent-induced immiscibility of polymer brushes eliminates dissipation channels. Nat Commun 2014; 5:3781. [DOI: 10.1038/ncomms4781] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 04/01/2014] [Indexed: 11/08/2022] Open
|
71
|
Chen Q, Kooij ES, Sui X, Padberg CJ, Hempenius MA, Schön PM, Vancso GJ. Collapse from the top: brushes of poly(N-isopropylacrylamide) in co-nonsolvent mixtures. SOFT MATTER 2014; 10:3134-42. [PMID: 24695793 DOI: 10.1039/c4sm00195h] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Using a combination of ellipsometry and friction force microscopy, we study the reversible swelling, collapse and variation in friction properties of covalently bound poly(N-isopropylacrylamide) (PNIPAM) layers on silicon with different grafting densities in response to exposure to good solvents and co-nonsolvent mixtures. Changes in the thickness and segment density distribution of grafted films are investigated by in situ ellipsometry. Based on quantitative modelling of the ellipsometry spectra, we postulate a structural model, which assumes that collapse takes place in the contacting layer between the brush and the co-nonsolvent and the top-collapsed brushes remain hydrated in the film interior. Using the structural model derived from ellipsometry spectra, we analyse the AFM based friction force microscopy data, which were obtained by silica colloidal probes. Results show a large increase of the friction coefficient of PNIPAM grafts when the grafts swollen by water are brought in contact with co-nonsolvents. For instance, the value of the friction coefficient for a medium density brush in water is four times lower than the value observed in a water-methanol (50% v/v) mixture. This increase of friction is accompanied by an increase in adherence between the PNIPAM chains and the silica colloidal probes, and is a result of chain collapse in the graft when contacted by a co-nonsolvent mixture in agreement with the model postulated on the basis of ellipsometric characterisation. The kinetic behaviour of the collapse is assessed by measuring the temporal variation of friction in situ as a function of elapsed time following contact with the co-nonsolvent as a function of graft density. In conclusion, the effect of co-nonsolvency influenced both the thickness of the PNIPAM brushes and the tribological behavior of the brush surfaces.
Collapse
Affiliation(s)
- Qi Chen
- Department of Materials Science and Technology of Polymers, University of Twente, MESA+ Institute for Nanotechnology, P.O. Box 217, 7500 AE Enschede, The Netherland.
| | | | | | | | | | | | | |
Collapse
|
72
|
Bhairamadgi NS, Pujari SP, Leermakers FAM, van Rijn CJM, Zuilhof H. Adhesion and friction properties of polymer brushes: fluoro versus nonfluoro polymer brushes at varying thickness. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:2068-2076. [PMID: 24555721 DOI: 10.1021/la404915k] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A series of different thicknesses of fluoro poly(2,2,2-trifluoroethyl methacrylate) and its analogous nonfluoro poly(ethyl methacrylate) polymer brushes were prepared via surface-initiated ATRP (SI-ATRP) on Si(111) surfaces. The thiol-yne click reaction was used to immobilize the SI-ATRP initiator with a high surface coverage, in order to achieve denser polymer brushes (grafting density from ~0.1 to 0.8 chains/nm(2)). All polymer brushes were characterized by static water contact angle measurements, infrared absorption reflection spectroscopy, and X-ray photoelectron spectroscopy. Adhesion and friction force measurements were conducted with silica colloidal probe atomic force microscopy (CP-AFM) under ambient and dry (argon) conditions. The fluoro poly(2,2,2-trifluoroethyl methacrylate) polymer showed a decrease in adhesion and friction with increasing thickness. The analogous nonfluoro poly(ethyl methacrylate) polymer brushes showed high adhesion and friction under ambient conditions. Friction coefficients down to 0.0057 (ambient conditions) and 0.0031 (dry argon) were obtained for poly(2,2,2-trifluoroethyl methacrylate) polymer brushes with 140 nm thickness, which are the lowest among these types of polymer brushes.
Collapse
Affiliation(s)
- Nagendra S Bhairamadgi
- Laboratory of Organic Chemistry and ‡Laboratory of Physical Chemistry and Colloid Science, Wageningen University and Research Center , Dreijenplein 8, 6703 HB Wageningen, The Netherlands
| | | | | | | | | |
Collapse
|
73
|
Lanotte L, Tomaiuolo G, Misbah C, Bureau L, Guido S. Red blood cell dynamics in polymer brush-coated microcapillaries: A model of endothelial glycocalyx in vitro. BIOMICROFLUIDICS 2014; 8:014104. [PMID: 24753725 PMCID: PMC3977877 DOI: 10.1063/1.4863723] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 01/19/2014] [Indexed: 05/19/2023]
Abstract
The confined flow of red blood cells (RBCs) in microvasculature is essential for oxygen delivery to body tissues and has been extensively investigated in the literature, both in vivo and in vitro. One of the main problems still open in microcirculation is that flow resistance in microcapillaries in vivo is higher than that in vitro. This discrepancy has been attributed to the glycocalyx, a macromolecular layer lining the inner walls of vessels in vivo, but no direct experimental evidence of this hypothesis has been provided so far. Here, we investigate the flow behavior of RBCs in glass microcapillaries coated with a polymer brush (referred to as "hairy" microcapillaries as opposed to "bare" ones with no coating), an experimental model system of the glycocalyx. By high-speed microscopy imaging and image analysis, a velocity reduction of RBCs flowing in hairy microcapillaries as compared to bare ones is indeed found at the same pressure drop. Interestingly, such slowing down is larger than expected from lumen reduction due to the polymer brush and displays an on-off trend with a threshold around 70 nm of polymer brush dry thickness. Above this threshold, the presence of the polymer brush is associated with an increased RBC deformation, and RBC velocity is independent on polymer brush thickness (at the same pressure drop). In conclusion, this work provides direct support to the hypothesis that the glycocalyx is the main factor responsible of the higher flow resistance found in microcapillaries in vivo.
Collapse
Affiliation(s)
- Luca Lanotte
- Dipartimento di Ingegneria chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli, Italy ; Univ. Grenoble 1/CNRS, LIPhy UMR 5588, BP 87, 38041 Grenoble, France
| | - Giovanna Tomaiuolo
- Dipartimento di Ingegneria chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli, Italy ; CEINGE, Advanced Biotechnologies, via G. Salvatore 486, 80145 Napoli, Italy
| | - Chaouqi Misbah
- Univ. Grenoble 1/CNRS, LIPhy UMR 5588, BP 87, 38041 Grenoble, France
| | - Lionel Bureau
- Univ. Grenoble 1/CNRS, LIPhy UMR 5588, BP 87, 38041 Grenoble, France
| | - Stefano Guido
- Dipartimento di Ingegneria chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli, Italy ; CEINGE, Advanced Biotechnologies, via G. Salvatore 486, 80145 Napoli, Italy
| |
Collapse
|
74
|
Lorbeer L, Alaghemandi M, Spohr E. Molecular dynamics studies of poly(N-isopropylacrylamide) endgrafted on the surfaces of model slab pores. J Mol Liq 2014. [DOI: 10.1016/j.molliq.2013.05.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
75
|
Poly(2-(dimethylamino)ethyl methacrylate) brushes fabricated by surface-mediated RAFT polymerization and their response to pH. Eur Polym J 2013. [DOI: 10.1016/j.eurpolymj.2013.07.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
76
|
Gong K, Marshall BD, Chapman WG. Modeling lower critical solution temperature behavior of associating polymer brushes with classical density functional theory. J Chem Phys 2013; 139:094904. [DOI: 10.1063/1.4819957] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
|
77
|
Bunk J, Drechsler A, Rauch S, Uhlmann P, Stamm M, Rennekamp R. The distribution of hydrophobized inorganic nanoparticles in thermoresponsive polymer nanocomposite films investigated by Scanning Probe and Electron Microscopy. Eur Polym J 2013. [DOI: 10.1016/j.eurpolymj.2013.03.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
78
|
Jalili K, Abbasi F, Milchev A. Surface Microdynamics Phase Transition and Internal Structure of High-Density, Ultrathin PHEMA-b-PNIPAM Diblock Copolymer Brushes on Silicone Rubber. Macromolecules 2013. [DOI: 10.1021/ma4003962] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- K. Jalili
- Institute of Polymeric Materials, Sahand University of Technology, Tabriz, Iran
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - F. Abbasi
- Institute of Polymeric Materials, Sahand University of Technology, Tabriz, Iran
| | - A. Milchev
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
- Institute for Physical Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| |
Collapse
|
79
|
Choi BC, Choi S, Leckband DE. Poly(N-isopropyl acrylamide) brush topography: dependence on grafting conditions and temperature. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:5841-5850. [PMID: 23600842 DOI: 10.1021/la400066d] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The topography of poly (N-isopropyl acrylamide) brushes end-grafted from initiator-terminated monolayers was imaged by atomic force microscopy, as a function of the area per chain and of solvent quality. Measurements were done in air and in water, below and above the lower critical solution temperature. At low grafting densities and molecular weights, area-averaged ellipsometry measurements did not detect changes in the volume of water-swollen, end-grafted polymer films above the lower critical solution temperature. However, atomic force microscopy images revealed surface features that suggest the formation of lateral aggregates or "octopus micelles". At high grafting densities and molecular weights, the films collapsed uniformly, as detected by both AFM imaging and ellipsometry. These findings reconcile in part prior results suggesting that some poly(N-isopropyl acrylamide) chains do not collapse in poor solvent, and they also reveal more complex collapse behavior above the lower critical solution temperature than is commonly assumed. This behavior would influence the ability to tune the functional properties of poly(N-isopropyl acrylamide) coatings.
Collapse
Affiliation(s)
- B-C Choi
- Department of Chemical and Biomolecular Engineering, University of Illinois, Urbana, Illinois 61801, United States
| | | | | |
Collapse
|
80
|
Balko SM, Kreer T, Costanzo PJ, Patten TE, Johner A, Kuhl TL, Marques CM. Polymer brushes under high load. PLoS One 2013; 8:e58392. [PMID: 23516470 PMCID: PMC3596396 DOI: 10.1371/journal.pone.0058392] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 02/04/2013] [Indexed: 11/25/2022] Open
Abstract
Polymer coatings are frequently used to provide repulsive forces between surfaces in solution. After 25 years of design and study, a quantitative model to explain and predict repulsion under strong compression is still lacking. Here, we combine experiments, simulations, and theory to study polymer coatings under high loads and demonstrate a validated model for the repulsive forces, proposing that this universal behavior can be predicted from the polymer solution properties.
Collapse
Affiliation(s)
- Suzanne M. Balko
- Department of Chemical Engineering and Materials Science, University of California Davis, Davis, California, United States of America
- Leibniz-Institut für Polymerforschung Dresden e.V., Dresden, Germany
| | - Torsten Kreer
- Leibniz-Institut für Polymerforschung Dresden e.V., Dresden, Germany
| | - Philip J. Costanzo
- Department of Chemistry, University of California Davis, Davis, California, United States of America
| | - Tim E. Patten
- Department of Chemistry, University of California Davis, Davis, California, United States of America
| | - Albert Johner
- Institut Charles Sadron, Université de Strasbourg, CNRS, Strasbourg, France
| | - Tonya L. Kuhl
- Department of Chemical Engineering and Materials Science, University of California Davis, Davis, California, United States of America
| | - Carlos M. Marques
- Institut Charles Sadron, Université de Strasbourg, CNRS, Strasbourg, France
| |
Collapse
|
81
|
Alaghemandi M, Spohr E. A molecular dynamics study of poly(N-isopropylacrylamide) endgrafted on a model cylindrical pore surface. RSC Adv 2013. [DOI: 10.1039/c3ra22266g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
82
|
Tamura A, Kobayashi J, Yamato M, Okano T. Thermally responsive microcarriers with optimal poly(N-isopropylacrylamide) grafted density for facilitating cell adhesion/detachment in suspension culture. Acta Biomater 2012; 8:3904-13. [PMID: 22813847 DOI: 10.1016/j.actbio.2012.07.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 05/14/2012] [Accepted: 07/10/2012] [Indexed: 12/29/2022]
Abstract
Large-scale cell culture of anchorage-dependent cells based on microcarriers is a crucial method for industrial-scale cell culture and large-scale expansion of therapeutic cells. Previously, the authors developed temperature-responsive microcarriers bearing poly(N-isopropylacrylamide) (PIPAAm)-grafted chains on their outer surface for the non-invasive detachment of cultured cells through temperature reduction without proteolytic enzyme treatment. In this study, to further facilitate cell adhesion and thermally induced detachment efficiency, PIPAAm-grafted beads with various grafted amounts and various grafted PIPAAm chain densities were prepared. Contact angle measurements at different temperatures revealed that the magnitude of the contact angle change from 37 to 20 °C decreased with increasing brush density. Additionally, the amount of fibronectin adsorbed on the bead surface decreased with increasing brush density. Chinese hamster ovary (CHO-K1) cells adhered to the surface of PIPAAm-grafted beads at 37 °C, and a negligible difference in the cell adhesive property was observed by varying the brush density of the PIPAAm-grafted beads. When the temperature was reduced to 20 °C, the adhering cells were found to detach themselves from the PIPAAm-grafted bead surfaces. Of particular interest, PIPAAm-grafted beads with intermediate brush density exhibited the highest efficiency of thermally induced cell detachment. Thus, the brush density of PIPAAm-grafted beads strongly affected the efficiency of thermally induced cell detachment.
Collapse
|
83
|
Lanotte L, Guido S, Misbah C, Peyla P, Bureau L. Flow reduction in microchannels coated with a polymer brush. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:13758-64. [PMID: 22935030 DOI: 10.1021/la302171a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We report on the design of microchannels made of glass capillary coated with polymer brushes elaborated by the so-called "grafting-from" technique. We present measurements of velocity profiles for pressure-driven flows of water in such "hairy" capillaries. We show that the flow reduction induced by the presence of the brush is unexpectedly greater than what could be anticipated from simple geometric arguments on the reduction of the effective capillary diameter or from predictions by models describing the brush layer as a poro-elastic boundary.
Collapse
Affiliation(s)
- Luca Lanotte
- University of Grenoble 1/CNRS, LIPhy UMR 5588, BP 87, 38041 Grenoble, France
| | | | | | | | | |
Collapse
|
84
|
Tucker AK, Stevens MJ. Study of the Polymer Length Dependence of the Single Chain Transition Temperature in Syndiotactic Poly(N-isopropylacrylamide) Oligomers in Water. Macromolecules 2012. [DOI: 10.1021/ma300729z] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Ashley K. Tucker
- Sandia National Laboratories, Albuquerque, New Mexico 87185-1395, United States
| | - Mark J. Stevens
- Sandia National Laboratories, Albuquerque, New Mexico 87185-1395, United States
| |
Collapse
|
85
|
Kooij ES, Sui X, Hempenius MA, Zandvliet HJW, Vancso GJ. Probing the Thermal Collapse of Poly(N-isopropylacrylamide) Grafts by Quantitative in Situ Ellipsometry. J Phys Chem B 2012; 116:9261-8. [DOI: 10.1021/jp304364m] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- E. Stefan Kooij
- Physics of Interfaces and Nanomaterials,
MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands
| | - Xiaofeng Sui
- Materials Science and Technology
of Polymers, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands
| | - Mark A. Hempenius
- Materials Science and Technology
of Polymers, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands
| | - Harold J. W. Zandvliet
- Physics of Interfaces and Nanomaterials,
MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands
| | - G. Julius Vancso
- Materials Science and Technology
of Polymers, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands
| |
Collapse
|
86
|
Theoretical considerations on mechanisms of harvesting cells cultured on thermoresponsive polymer brushes. Biomaterials 2012; 33:4975-87. [DOI: 10.1016/j.biomaterials.2012.03.060] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 03/17/2012] [Indexed: 11/20/2022]
|
87
|
Dou Y, Han J, Wang T, Wei M, Evans DG, Duan X. Temperature-controlled electrochemical switch based on layered double hydroxide/poly(N-isopropylacrylamide) ultrathin films fabricated via layer-by-layer assembly. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:9535-42. [PMID: 22650232 DOI: 10.1021/la3012603] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this paper we report the fabrication of layered double hydroxide (LDH) nanoparticles/poly(N-isopropylacrylamide) (pNIPAM) ultrathin films (UTFs) via the layer-by-layer assembly technique, and their switchable electrocatalytic performance in response to temperature stimuli was demonstrated. X-ray diffraction and UV-vis absorption spectroscopy indicate a periodic layered structure with uniform and regular growth of the (LDH/pNIPAM)(n) UTFs; an interaction based on hydrogen bonding between LDH nanoparticles and pNIPAM was confirmed by X-ray-photoelectron spectroscopy and Fourier transform infrared spectroscopy. Temperature-triggered cyclic voltammetry and electrochemical impedance spectroscopy switch for the UTFs was obtained between 20 and 40 °C, accompanied by reversible changes in surface topography and film thickness revealed by atomic force microscopy and ellipsometry, respectively. The electrochemical on-off property of the temperature-controlled (LDH/pNIPAM)(n) UTFs originates from the contraction-expansion configuration of pNIPAM with low-high electrochemical impedance. In addition, a switchable electrocatalytic behavior of the (LDH/pNIPAM)(n) UTFs toward the oxidation of glucose was observed, resulting from the temperature-controlled charge transfer rate. Therefore, this work provides a facile approach for the design and fabrication of a well-ordered command interface with a temperature-sensitive property, which can be potentially applied in electrochemical sensors and switching.
Collapse
Affiliation(s)
- Yibo Dou
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China
| | | | | | | | | | | |
Collapse
|
88
|
Mandal K, Balland M, Bureau L. Thermoresponsive micropatterned substrates for single cell studies. PLoS One 2012; 7:e37548. [PMID: 22701519 PMCID: PMC3365108 DOI: 10.1371/journal.pone.0037548] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 04/25/2012] [Indexed: 02/02/2023] Open
Abstract
We describe the design of micropatterned surfaces for single cell studies, based on thermoresponsive polymer brushes. We show that brushes made of poly(N-isopropylacrylamide) grafted at high surface density display excellent protein and cell anti-adhesive properties. Such brushes are readily patterned at the micron scale via deep UV photolithography. A proper choice of the adhesive pattern shapes, combined with the temperature-dependent swelling properties of PNIPAM, allow us to use the polymer brush as a microactuator which induces cell detachment when the temperature is reduced below C.
Collapse
Affiliation(s)
| | - Martial Balland
- Laboratoire Interdisciplinaire de Physique UMR 5588, Univ. Grenoble 1/CNRS, Grenoble, France
- * E-mail: (MB); (LB)
| | - Lionel Bureau
- Laboratoire Interdisciplinaire de Physique UMR 5588, Univ. Grenoble 1/CNRS, Grenoble, France
- * E-mail: (MB); (LB)
| |
Collapse
|
89
|
Xu Y, Chen X, Chen H, Xu S, Liu H, Hu Y. Density functional theory for the selective adsorption of small molecules on a surface modified with polymer brushes. MOLECULAR SIMULATION 2012. [DOI: 10.1080/08927022.2011.616892] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
90
|
Bittrich E, Burkert S, Müller M, Eichhorn KJ, Stamm M, Uhlmann P. Temperature-sensitive swelling of poly(N-isopropylacrylamide) brushes with low molecular weight and grafting density. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:3439-3448. [PMID: 22239605 DOI: 10.1021/la204230a] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Temperature-sensitive poly(N-isopropylacrylamide) (PNIPAAm) brushes with different molecular weights M(n) and grafting densities σ were prepared by the "grafting-to" method. Changes in their physicochemical properties according to temperature were investigated with the help of in situ spectroscopic ellipsometry and in situ attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy. Brush criteria indicate a transition between a brush conformation below the lower critical solution temperature (LCST) and an intermediate to mushroom conformation above the LCST. By in situ ellipsometry distinct changes in the brush layer parameters (wet thickness, refractive index, buffer content) were observed. A broadening of the temperature region with maximum deswelling occurred with decreasing grafting density. The brush layer properties were independent of the grafting density below the LCST, but showed a virtually monotonic behavior above the LCST. The midtemperature ϑ(half) of the deswelling process increased with increasing grafting density. Thus grafting density-dependent design parameters for such functional films were presented. For the first time, ATR-FTIR spectroscopy was used to monitor segment density and hydrogen bonding changes of these very thin PNIPAAm brushes as a function of temperature based on significant variations of the methyl stretching, Amide I, as well as Amide II bands with respect to intensity and wavenumber position. No dependence on M(n) and σ in the wavenumber shift of these bands above the LCST was found. The temperature profile of these band intensities and thus segment density was found to be rather step-like, exceeding temperatures around the LCST, while the respective profile of their wavenumber positions suggested continuous structural and hydration processes. Remaining buffer amounts and residual intermolecular segment/water interaction in the collapsed brushes above the LCST could be confirmed by both in situ methods.
Collapse
Affiliation(s)
- Eva Bittrich
- Leibniz Institute of Polymer Research Dresden, Hohe Strasse 6, D-01069 Dresden, Germany
| | | | | | | | | | | |
Collapse
|
91
|
Kamperman M, Synytska A. Switchable adhesion by chemical functionality and topography. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm31747h] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
92
|
Elliott LCC, Barhoum M, Harris JM, Bohn PW. Single molecule tracking studies of lower critical solution temperature transition behavior in poly(N-isopropylacrylamide). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:11037-11043. [PMID: 21770465 DOI: 10.1021/la201753v] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Spatial and temporal heterogeneities in expanded and collapsed surface bound poly(N-isopropylacrylamide), pNIPAAm, films are studied by single molecule tracking (SMT) experiments. Tracking data are analyzed using both radius of gyration (R(g)) evolution and confinement level calculations to elucidate the range of behaviors displayed by single Rhodamine6G (R6G) molecules. Confined diffusion that is dictated by the free volume within surface tethered chains is observed with considerable dispersion among individual R6G molecules. Thus, the distribution of probe behavior reflects nanometer-scale information about the behavior of the probe-polymer system at temperatures above (T > T(LCST)) and below (T < T(LCST)) the lower critical solution temperature (LCST). In this context, confinement-level analysis and R(g) evolution both show a larger degree of confinement of the probe in pNIPAAm at T > T(LCST). Temperature-dependent changes in confinement are evidenced at T > T(LCST) by a higher percentage of confined steps, longer periods of confined events, and smaller area of confined zones, as well as a shift in the overall distribution of R(g) evolution paths and final R(g) distributions.
Collapse
Affiliation(s)
- Lindsay C C Elliott
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, USA
| | | | | | | |
Collapse
|
93
|
Precise control of surface physicochemical properties for electrospun fiber mats by surface-initiated radical polymerization. Polym J 2011. [DOI: 10.1038/pj.2011.80] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
94
|
Halperin A, Kröger M. Collapse of Thermoresponsive Brushes and the Tuning of Protein Adsorption. Macromolecules 2011. [DOI: 10.1021/ma201006h] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- A. Halperin
- University of Grenoble 1/CNRS, LIPhy UMR 5588, BP 87, 38041 Grenoble, France
| | - M. Kröger
- Polymer Physics, ETH Zurich, Wolfgang-Pauli-Strasse 10, CH-8093 Zurich, Switzerland
| |
Collapse
|
95
|
Sui X, Chen Q, Hempenius MA, Vancso GJ. Probing the collapse dynamics of poly(N-isopropylacrylamide) brushes by AFM: effects of co-nonsolvency and grafting densities. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2011; 7:1440-7. [PMID: 21506265 DOI: 10.1002/smll.201002229] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 01/17/2011] [Indexed: 05/05/2023]
Abstract
Collapse of poly(N-isopropylacrylamide) (PNIPAM) brushes in the mixed solvent system (water/methanol 50% v/v) is studied by in-situ atomic-force microscopy (AFM). PNIPAM brushes with three different grafting densities and similar chain lengths are synthesized via surface-initiated atom-transfer radical polymerization. By changing the solvent from water to a water/methanol (50% v/v) mixture, the polymer brushes switch from a swollen to collapsed state. AFM force measurements using a silica colloidal probe attached to the tip are employed to obtain the Young's moduli of the polymer brushes in different solvation states. The collapse dynamics of the brush is followed by monitoring the pull-off force (adherence) in situ. The modulus of the swollen high-density polymer brush is four times lower than that of the same brush in the collapsed state. It is shown that in the case of the high-density polymer brush with a thickness (t(in water) ) of 900 nm, the collapse takes place in a time scale of ~25 s, whereas the collapse occurs faster for the medium-density brush (t(in water) = 630 nm) and much more rapidly for the low-density brush (t(in water) = 80 nm). This difference in the response kinetics is primarily ascribed to the time needed for solvent exchange in the polymer brushes.
Collapse
Affiliation(s)
- Xiaofeng Sui
- Department of Materials Science and Technology of Polymers, University of Twente, MESA+ Institute for Nanotechnology, Enschede, The Netherlands
| | | | | | | |
Collapse
|
96
|
Gehan H, Mangeney C, Aubard J, Lévi G, Hohenau A, Krenn JR, Lacaze E, Félidj N. Design and Optical Properties of Active Polymer-Coated Plasmonic Nanostructures. J Phys Chem Lett 2011; 2:926-31. [PMID: 26295630 DOI: 10.1021/jz200272r] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The grafting of stimuli-responsive polymer brushes on plasmonic structures provides a perfectly controlled two-dimensional active device with optical properties that can be modified through external stimuli. Herein, we demonstrate thermally induced modifications of the plasmonic response of lithographic gold nanoparticles functionalized by thermosensitive polymer brushes of (poly(N-isopropylacrylamide), PNIPAM). Optical modifications result from refractive local index changes due to a phase transition from a hydrophilic state (swollen regime) to a hydrophobic state (collapsed regime) of the polymer chains occurring in a very small range of temperatures. The refractive index of the polymer in aqueous solution is estimated in both states, deduced from the discrete dipole approximation (DDA) method. The combination of lithographic gold NPs and thermoresponsive polymer chains leads to a new generation of perfectly calibrated and dynamically controlled hybrid gold/polymer system for real-time nanosensors.
Collapse
Affiliation(s)
- Hélène Gehan
- †Laboratoire ITODYS, Université Paris Diderot, CNRS UMR 7086, 15 rue Jean de Baïf, 75013 Paris, France
| | - Claire Mangeney
- †Laboratoire ITODYS, Université Paris Diderot, CNRS UMR 7086, 15 rue Jean de Baïf, 75013 Paris, France
| | - Jean Aubard
- †Laboratoire ITODYS, Université Paris Diderot, CNRS UMR 7086, 15 rue Jean de Baïf, 75013 Paris, France
| | - Georges Lévi
- †Laboratoire ITODYS, Université Paris Diderot, CNRS UMR 7086, 15 rue Jean de Baïf, 75013 Paris, France
| | - Andreas Hohenau
- ‡Institute of Physics, Karl Franzens University, Universitatsplatz 5, A-8010 Graz, Austria
| | - Joachim R Krenn
- ‡Institute of Physics, Karl Franzens University, Universitatsplatz 5, A-8010 Graz, Austria
| | - Emmanuelle Lacaze
- §Laboratoire INSP, Université Pierre et Marie Curie, 5 place Jussieu, 75005 Paris, France
| | - Nordin Félidj
- †Laboratoire ITODYS, Université Paris Diderot, CNRS UMR 7086, 15 rue Jean de Baïf, 75013 Paris, France
| |
Collapse
|
97
|
Sui X, Di Luca A, Gunnewiek MK, Kooij ES, van Blitterswijk CA, Moroni L, Hempenius MA, Vancso GJ. Stability and Cell Adhesion Properties of Poly(N-isopropylacrylamide) Brushes with Variable Grafting Densities. Aust J Chem 2011. [DOI: 10.1071/ch11168] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Poly(N-isopropylacrylamide) brushes with three different grafting densities were synthesized via surface-initiated atom-transfer radical polymerization on glass or on silicon substrates. The substrates were modified with monochlorosilane-based or trimethoxysilane-based atom-transfer radical polymerization initiators. Atomic force microscopy images showed detachment of brushes from the monochlorosilane-based system under cell culture conditions. In situ ellipsometry demonstrated the reversible swelling and collapse of the brushes as the temperature was varied across the lower critical solution temperature of poly(N-isopropylacrylamide) in pure water. The polymer brushes were evaluated as supporting substrates for MC-3T3 cell cultures. At 37°C (T>lower critical solution temperature), the seeded cells adhered, spread, and proliferated, whereas at 25°C (T<lower critical solution temperature), the cells detached from the surface. The low-density polymer brush showed the highest cell adhesion, featuring adhering cells with an elongated morphology.
Collapse
|
98
|
Gehan H, Fillaud L, Chehimi MM, Aubard J, Hohenau A, Felidj N, Mangeney C. Thermo-induced electromagnetic coupling in gold/polymer hybrid plasmonic structures probed by surface-enhanced raman scattering. ACS NANO 2010; 4:6491-6500. [PMID: 21028846 DOI: 10.1021/nn101451q] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This paper describes a general stepwise strategy combining diazonium salt, surface-initiated atom transfer radical polymerization (SI-ATRP), and click chemistry for an efficient gold surface functionalization by poly(N-isopropylacrylamide) (PNIPAM) brushes and gold nanoparticle assemblies. We designed by this way a new plasmonic device made of gold nanoparticles separated from a gold film through a thermoresponsive polymer layer. This organic layer responds to temperature variations by conformational changes (with a characteristic temperature called the lower critical solution temperature, LCST) and is therefore able to vary the distance between the gold nanoparticles and the gold film. The optical properties of these stimulable substrates were probed by surface-enhanced raman scattering (SERS) using methylene blue (MB) as a molecular probe. We show that an increase of the external temperature reversibly induces a significant enhancement of the MB SERS signal. This was attributed to a stronger interaction between the gold nanoparticles and the gold substrate. The temperature-responsive plasmonic devices developed in this paper thus provide a dynamic SERS platform, with thermally switchable electromagnetic coupling between the gold nanoparticles and the gold surface.
Collapse
Affiliation(s)
- Hélène Gehan
- ITODYS, Université Paris Diderot-Paris 7 (UMR CNRS 7086), 15 rue Jean de Baïf, 75013 Paris, France
| | | | | | | | | | | | | |
Collapse
|
99
|
Ishida N, Biggs S. Effect of Grafting Density on Phase Transition Behavior for Poly(N-isopropylacryamide) Brushes in Aqueous Solutions Studied by AFM and QCM-D. Macromolecules 2010. [DOI: 10.1021/ma101113g] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Naoyuki Ishida
- School of Process, Environmental and Materials Engineering, University of Leeds, Leeds LS2 9JT, U.K
- Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 306-8565, Japan
| | - Simon Biggs
- School of Process, Environmental and Materials Engineering, University of Leeds, Leeds LS2 9JT, U.K
| |
Collapse
|
100
|
Asoh TA, Kikuchi A. Electrophoretic adhesion of stimuli-responsive hydrogels. Chem Commun (Camb) 2010; 46:7793-5. [DOI: 10.1039/c0cc01874k] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|