101
|
Rahane SB, Kilbey SM, Metters AT. Kinetics of Surface-Initiated Photoiniferter-Mediated Photopolymerization. Macromolecules 2005. [DOI: 10.1021/ma0509661] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Santosh B. Rahane
- Department of Chemical and Biomolecular Engineering, Clemson University, Clemson, South Carolina 29634, and Department of Bioengineering, Clemson University, Clemson, South Carolina 29634
| | - S. Michael Kilbey
- Department of Chemical and Biomolecular Engineering, Clemson University, Clemson, South Carolina 29634, and Department of Bioengineering, Clemson University, Clemson, South Carolina 29634
| | - Andrew T. Metters
- Department of Chemical and Biomolecular Engineering, Clemson University, Clemson, South Carolina 29634, and Department of Bioengineering, Clemson University, Clemson, South Carolina 29634
| |
Collapse
|
102
|
Affiliation(s)
- Heqing Huang
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506-0046
| | - Lynn S. Penn
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506-0046
| |
Collapse
|
103
|
Makal U, Wynne KJ. Water induced hydrophobic surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:3742-3745. [PMID: 15835931 DOI: 10.1021/la050357m] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A polyurethane coating is described that has hydrophilic wetting behavior when dry and hydrophobic when wet. A difference of approximately 25 degrees in advancing contact angles for dry (83 degrees ) and wet (108 degrees ) states is found by sessile drop and dynamic methods. The term "contraphilic" is suggested for this reversible change opposite customary amphiphilic behavior. Contraphilic behavior results from a soft block containing semifluorinated and 5,5-dimethyhydantoin segmers. Amide inter/intramolecular hydrogen bonding is proposed for the hydrophilic (dry) state, while surface-confined, amide-water hydrogen bonding "releases"semifluorinated groups, giving the hydrophobic state. Water-induced hydrophobic surfaces may lead to applications for easily switched wetting, such as in microfluidics.
Collapse
|
104
|
Li D, Sheng X, Zhao B. Environmentally Responsive “Hairy” Nanoparticles: Mixed Homopolymer Brushes on Silica Nanoparticles Synthesized by Living Radical Polymerization Techniques. J Am Chem Soc 2005; 127:6248-56. [PMID: 15853330 DOI: 10.1021/ja0422561] [Citation(s) in RCA: 265] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This article reports on the preparation of environmentally responsive "hairy" nanoparticles by growth of mixed poly(tert-butyl acrylate) (PtBA)/polystyrene (PS) brushes from silica particles using living radical polymerization techniques and subsequent hydrolysis of PtBA to produce amphiphilic mixed poly(acrylic acid) (PAA)/PS brushes. Silica particles were synthesized by the Stober process and were functionalized with an asymmetric difunctional initiator-terminated monolayer. Surface-initiated atom transfer radical polymerization of tBA was carried out in the presence of a free initiator. Kinetics study showed that the polymerization was well controlled. By cleaving PtBA off the particles, the molecular weights of the grafted and free polymers were found to be essentially identical. Mixed PtBA/PS brushes were obtained by the nitroxide-mediated radical polymerization of styrene from PtBA particles. The M(n) of the grafted PS was found to be the same as that of the free PS formed in the solution from the free initiator. Amphiphilic mixed PAA/PS brush-coated nanoparticles were synthesized from mixed PtBA/PS particles by hydrolysis of PtBA with iodotrimethylsilane. Tyndall scattering experiments and (1)H NMR study showed that the mixed PAA/PS particles can be dispersed and form a stable suspension in CHCl(3), a selective solvent for PS, and also in CH(3)OH, a selective solvent for PAA, demonstrating the capability of these hairy nanoparticles to undergo chain reorganization in response to environmental changes.
Collapse
Affiliation(s)
- Dejin Li
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA
| | | | | |
Collapse
|
105
|
Lin YH, Teng J, Zubarev ER, Shulha H, Tsukruk VV. In-situ observation of switchable nanoscale topography for y-shaped binary brushes in fluids. NANO LETTERS 2005; 5:491-495. [PMID: 15755100 DOI: 10.1021/nl0479029] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Direct, in-fluid observation of the surface morphology and nanomechanical properties of the mixed brushes composed of Y-shaped binary molecules PS-PAA revealed nanoscale network-like surface topography formed by coexisting stretched soluble PAA arms and collapsed insoluble PS chains in water. Placement of Y-shaped brushes in different fluids resulted in dramatic reorganization ranging from soft repellent layer covered by swollen PS arms in toluene to an adhesive, mixed layer composed of coexisting swollen PAA and collapsed PS arms in water. These binary layers with the overall nanoscale thickness can serve as adaptive nanocoatings with stimuli-responsive properties.
Collapse
Affiliation(s)
- Yen-Hsi Lin
- Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011, USA
| | | | | | | | | |
Collapse
|
106
|
Ogoshi T, Chujo Y. Synthesis of anionic polymer–silica hybrids by controlling pH in an aqueous solution. ACTA ACUST UNITED AC 2005. [DOI: 10.1039/b411448e] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
107
|
Zhao B. A combinatorial approach to study solvent-induced self-assembly of mixed poly(methyl methacrylate)/polystyrene brushes on planar silica substrates: effect of relative grafting density. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:11748-11755. [PMID: 15595807 DOI: 10.1021/la047681m] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This article reports the study of the effect of relative grafting densities of two polymer chains on solvent-induced self-assembly of mixed poly(methyl methacrylate) (PMMA)/polystyrene (PS) brushes through a combinatorial approach. Gradient-mixed PMMA/PS brushes were synthesized from a gradient-mixed initiator-terminated monolayer by combining atom transfer radical polymerization (ATRP) and nitroxide mediated radical polymerization (NMRP) in a two-step process. The gradient-mixed initiator-terminated monolayer was fabricated by first formation of a gradient in density of an ATRP initiator through vapor diffusion followed by backfilling of an NMRP-initiator-terminated trichlorosilane. After treatment of a gradient-mixed brush whose PS Mn was slightly lower than that of PMMA with glacial acetic acid, a selective solvent for PMMA, relatively ordered nanodomains were observed in the region where the ratio of PS to PMMA grafting density (number of polymer chains/nm2) was in the range from 0.67 to 2.17 and the overall grafting density was approximately 0.85 polymer chains/nm2. Contact angle hysteresis were high (> or =40 degrees ) in this region and XPS studies confirmed that the PMMA chains were enriched at the outermost layer. The nanodomains are speculated to be of a micellar structure with PS chains forming the core shielded by PMMA chains.
Collapse
Affiliation(s)
- Bin Zhao
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA.
| |
Collapse
|
108
|
Tokareva I, Minko S, Fendler JH, Hutter E. Nanosensors Based on Responsive Polymer Brushes and Gold Nanoparticle Enhanced Transmission Surface Plasmon Resonance Spectroscopy. J Am Chem Soc 2004; 126:15950-1. [PMID: 15584714 DOI: 10.1021/ja044575y] [Citation(s) in RCA: 230] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Swelling (and shrinking) of poly(2-vinylpyridine), P2VP, polymer brushes, caused by pH changes, could be readily monitored by transmission surface plasmon resonance, T-SPR, spectroscopy. Gold nanoparticles attached to the P2VP polymer brushes dramatically enhanced the pH-induced shift in the T-SPR absorption spectra. (A 50 nm shift of the absorption maximum of the T-SPR spectrum of the supporting gold nanoislands was observed upon changing the pH from 5.0 to 2.0, corresponding to a swelling of the polymer brushes from 8.1 +/- 0.7 to 24.0 +/- 2.0 nm. Same shift in the opposite direction was observed upon changing the pH from 2.0 to 5.0.)
Collapse
Affiliation(s)
- Iryna Tokareva
- Department of Chemistry, Clarkson University, Potsdam, New York 13699, USA
| | | | | | | |
Collapse
|
109
|
Feng J, Haasch RT, Dyer DJ. Photoinitiated Synthesis of Mixed Polymer Brushes of Polystyrene and Poly(methyl methacrylate). Macromolecules 2004. [DOI: 10.1021/ma048681w] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jianxin Feng
- Department of Chemistry, Southern Illinois University, Carbondale, Illinois 62901-4409, and The Frederick Seitz Materials Research Laboratory, University of Illinois, 104 S. Goodwin, MC 230, Urbana, Illinois 61801
| | - Richard T. Haasch
- Department of Chemistry, Southern Illinois University, Carbondale, Illinois 62901-4409, and The Frederick Seitz Materials Research Laboratory, University of Illinois, 104 S. Goodwin, MC 230, Urbana, Illinois 61801
| | - Daniel J. Dyer
- Department of Chemistry, Southern Illinois University, Carbondale, Illinois 62901-4409, and The Frederick Seitz Materials Research Laboratory, University of Illinois, 104 S. Goodwin, MC 230, Urbana, Illinois 61801
| |
Collapse
|
110
|
Yang C, Kizhakkedathu JN, Brooks DE, Jin F, Wu C. Laser-Light-Scattering Study of Internal Motions of Polymer Chains Grafted on Spherical Latex Particles. J Phys Chem B 2004. [DOI: 10.1021/jp047403w] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Cheng Yang
- Department of Chemical and Material Engineering, Southern Yangtze University, Wuxi, Jiangsu, People's Republic of China, Department of Pathology and Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada, Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, and The Open Laboratory of Bond Selective Chemistry, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
| | - Jayachandran N. Kizhakkedathu
- Department of Chemical and Material Engineering, Southern Yangtze University, Wuxi, Jiangsu, People's Republic of China, Department of Pathology and Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada, Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, and The Open Laboratory of Bond Selective Chemistry, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
| | - Donald E. Brooks
- Department of Chemical and Material Engineering, Southern Yangtze University, Wuxi, Jiangsu, People's Republic of China, Department of Pathology and Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada, Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, and The Open Laboratory of Bond Selective Chemistry, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
| | - Fan Jin
- Department of Chemical and Material Engineering, Southern Yangtze University, Wuxi, Jiangsu, People's Republic of China, Department of Pathology and Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada, Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, and The Open Laboratory of Bond Selective Chemistry, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
| | - Chi Wu
- Department of Chemical and Material Engineering, Southern Yangtze University, Wuxi, Jiangsu, People's Republic of China, Department of Pathology and Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada, Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, and The Open Laboratory of Bond Selective Chemistry, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
| |
Collapse
|
111
|
Ionov L, Houbenov N, Sidorenko A, Stamm M, Luzinov I, Minko S. Inverse and reversible switching gradient surfaces from mixed polyelectrolyte brushes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:9916-9919. [PMID: 15518474 DOI: 10.1021/la048158a] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We report on a thin polyelectrolyte film (mixed polyelectrolyte brush) with a gradual change of the composition (ratio between two different oppositely charged surface-grafted weak polyelectrolytes) across the sample. The gradient of surface composition creates a gradient in surface charge density and, consequently, a gradient of the wetting behavior. The gradient film is sensitive to a pH signal and can be reversibly switched via pH change.
Collapse
Affiliation(s)
- Leonid Ionov
- Institute for Polymer Research Dresden, Dresden, Germany
| | | | | | | | | | | |
Collapse
|
112
|
Lemieux MC, Julthongpiput D, Bergman KN, Cuong PD, Ahn HS, Lin YH, Tsukruk VV. Ultrathin binary grafted polymer layers with switchable morphology. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:10046-10054. [PMID: 15518492 DOI: 10.1021/la048496b] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Polymer surface layers comprised of mixed chains grafted to a functionalized silicon surface with a total layer thickness of only 1-3 nm are shown to exhibit reversible switching of their structure. Carboxylic acid-terminated polystyrene (PS) and poly (butyl acrylate) (PBA) were chemically attached to a silicon surface that was modified with an epoxysilane self-assembled monolayer by a "grafting to" routine. While one-step grafting resulted in large, submicron microstructures, a refined, two-step sequential grafting procedure allowed for extremely small spatial dimensions of PS and PBA domains. By adjusting the grafting parameters, such as concentration of each phase and molecular weight, very finely structured surfaces resulted with roughly 10-nm phase domains and less than 0.5-nm roughness. Combining the glassy PS and the rubbery PBA, we implemented a design approach to fabricate a mixed brush from two immiscible polymers so that switching of the surface nanomechanical properties is possible. Post-grafting hydrolysis converted PBA to poly(acrylic acid) to amplify this switching in surface wettability. Preliminary tribological studies showed a difference in wear behavior of glassy and rubbery surface layers. Such switchable coatings have practical applications as surface modifications of complex nanoscale electronic devices and sensors, which is why we restricted total thickness for potential nanoscale gaps.
Collapse
Affiliation(s)
- Melburne C Lemieux
- Materials Science & Engineering Department, Iowa State University, Ames, Iowa 50011, USA
| | | | | | | | | | | | | |
Collapse
|
113
|
|
114
|
Zhao B, Haasch RT, MacLaren S. Self-reorganization of mixed poly(methyl methacrylate)/polystyrene brushes on planar silica substrates in response to combined selective solvent treatments and thermal annealing. POLYMER 2004. [DOI: 10.1016/j.polymer.2004.09.048] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
115
|
Ionov L, Sidorenko A, Stamm M, Minko S, Zdyrko B, Klep V, Luzinov I. Gradient Mixed Brushes: “Grafting To” Approach. Macromolecules 2004. [DOI: 10.1021/ma049147r] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | - Sergiy Minko
- Chemistry Department, Clarkson University, Potsdam, New York 13699
| | | | | | | |
Collapse
|
116
|
Luzinov I, Minko S, Tsukruk VV. Adaptive and responsive surfaces through controlled reorganization of interfacial polymer layers. Prog Polym Sci 2004. [DOI: 10.1016/j.progpolymsci.2004.03.001] [Citation(s) in RCA: 414] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
117
|
Huang H, Penn LS, Quirk RP, Cheong TH. Kinetics of Sequential Tethering in Formation of Mixed Layers. Macromolecules 2004. [DOI: 10.1021/ma030591o] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
118
|
Zhao B, Haasch RT, MacLaren S. Solvent-Induced Self-Assembly of Mixed Poly(methyl methacrylate)/Polystyrene Brushes on Planar Silica Substrates: Molecular Weight Effect. J Am Chem Soc 2004; 126:6124-34. [PMID: 15137778 DOI: 10.1021/ja049570f] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The effect of molecular weight on the solvent-induced self-assembly of mixed poly(methyl methacrylate) (PMMA)/polystyrene (PS) brushes on silicon wafers was studied. For a series of mixed brushes with a fixed PMMA M(n) and systematically changed PS M(n), a transition in water advancing contact angle (theta(a)) from 74 degrees, the value for a flat PMMA surface, to 91 degrees, the value for a flat PS film, was observed with increasing PS M(n) after treatment with CHCl(3). Atomic force microscopy studies showed smooth surfaces for all samples. While no significant changes in surface morphologies were observed after treatment with cyclohexane, a selective solvent for PS, contact angle and XPS studies indicated that the mixed brushes with a PS M(n) slightly smaller than that of PMMA underwent self-reorganization, exhibiting a different theta(a). Intriguing surface morphologies composed of relatively ordered nanoscale domains were found from mixed brushes with PS M(n) slightly smaller than or similar to that of PMMA after treatment with acetic acid, a selective solvent for PMMA. The nanodomains are speculated to be of a micellar structure, with PS chains forming a core shielded by PMMA chains.
Collapse
Affiliation(s)
- Bin Zhao
- Department of Chemistry, University of Tennessee at Knoxville, Knoxville, Tennessee 37996, USA
| | | | | |
Collapse
|
119
|
Zhao H, Argoti SD, Farrell BP, Shipp DA. Polymer-silicate nanocomposites produced by in situ
atom transfer radical polymerization. ACTA ACUST UNITED AC 2004. [DOI: 10.1002/pola.11071] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
120
|
Julthongpiput D, Lin YH, Teng J, Zubarev ER, Tsukruk VV. Y-Shaped Amphiphilic Brushes with Switchable Micellar Surface Structures. J Am Chem Soc 2003; 125:15912-21. [PMID: 14677983 DOI: 10.1021/ja038051u] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We observed novel nanoscale surface structures of segregated pinned micelles and craterlike micelles formed by grafted Y-shaped molecules and their reversible reorganization in selective solvents. The Y-shaped molecules have two incompatible polymer chains (polystyrene and poly(tert-butyl acrylate)) attached to a functional stemlike segment capable of covalent grafting to a functionalized silicon surface. Postgrafting hydrolysis of poly(tert-butyl acrylate) arms imparts amphiphilicity to the brush. We demonstrated that spatial constraints induced by a chemical junction of two relatively short (6-10 nm) dissimilar arms in such Y-shaped molecules lead to the formation of segregated micellar surface nanostructures in the grafted layer. We proposed a model of these segregated pinned micelles and the corresponding reverse micelles (craterlike structures) featuring different segregation states of hydrophobic polystyrene and hydrophilic poly(acrylic acid) arms. The arms undergo conformational rearrangements in selective solvents in a controlled and reversible fashion. These nanoscale structural reorganizations define adaptive macroscopic wetting surface properties of the amphiphilic Y-shaped brushes. This surface structure and switchable behavior can be considered as a promising way toward the patterning of solid substrates with adaptive nanowells, which could be used for trapping of adsorbing nanoscale objects.
Collapse
Affiliation(s)
- Duangrut Julthongpiput
- Department of Materials Science & Engineering, Iowa State University, Ames, Iowa 50011, USA
| | | | | | | | | |
Collapse
|