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Cimatu KLA, Premadasa UI, Ambagaspitiya TD, Adhikari NM, Jang JH. Evident phase separation and surface segregation of hydrophobic moieties at the copolymer surface using atomic force microscopy and SFG spectroscopy. J Colloid Interface Sci 2020; 580:645-659. [PMID: 32712471 DOI: 10.1016/j.jcis.2020.07.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/12/2020] [Accepted: 07/13/2020] [Indexed: 11/18/2022]
Abstract
HYPOTHESIS Copolymers are developed to enhance the overall physical and chemical properties of polymers. The surface nature of a copolymer is relevant to creating efficient materials to improve adhesion and biocompatibility. We hypothesize that the improved adhesion, as a surface property, is due to phase separation, surface segregation, and the overall molecular organization of different polymer components at the copolymer surface. EXPERIMENTS The surface structure of a copolymer composed of 2-hydroxyethyl methacrylate (HEMA) monomer and 2-phenoxyethyl methacrylate (PhEMA) monomer was analyzed in comparison to the polyHEMA and polyPhEMA homopolymers using atomic force microscopy (AFM) and sum frequency generation (SFG) spectroscopy. FINDINGS The contrast in the phase images was due to the variance in the hydrophobic level provided by the hydroxyl and phenoxy modified monomers in the copolymer. The distribution of the adhesion values, supporting the presence of hydrophobic moieties, across the polymer surface defined the surface segregation of these two components. SFG spectra of the copolymer thin film showed combined spectral features of both polyHEMA and polyPhEMA thin films at the polymer surface. The tilt angles of the alpha-methyl group of homopolymers using the polarization intensity ratio analysis and the polarization mapping method were estimated to be in the range from 48° to 66°.
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Affiliation(s)
- Katherine Leslee A Cimatu
- Department of Chemistry and Biochemistry, Ohio University, 100 University Terrace, 136 Clippinger Laboratories, Athens, OH 45701-2979, United States.
| | - Uvinduni I Premadasa
- Department of Chemistry and Biochemistry, Ohio University, 100 University Terrace, 136 Clippinger Laboratories, Athens, OH 45701-2979, United States
| | - Tharushi D Ambagaspitiya
- Department of Chemistry and Biochemistry, Ohio University, 100 University Terrace, 136 Clippinger Laboratories, Athens, OH 45701-2979, United States
| | - Narendra M Adhikari
- Department of Chemistry and Biochemistry, Ohio University, 100 University Terrace, 136 Clippinger Laboratories, Athens, OH 45701-2979, United States
| | - Joon Hee Jang
- Department of Nanomedicine, Houston Methodist Research Institute, 6670 Bertner Avenue, Houston, TX 77030, United States
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Zhou Y, Yu F, Deng H, Huang Y, Li G, Fu Q. Morphology Evolution of Polymer Blends under Intense Shear During High Speed Thin-Wall Injection Molding. J Phys Chem B 2017; 121:6257-6270. [PMID: 28590755 DOI: 10.1021/acs.jpcb.7b03374] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The morphology evolution under shear during different processing is indeed an important issue regarding the phase morphology control as well as final physical properties of immiscible polymer blends. High-speed thin wall injection molding (HSTWIM) has recently been demonstrated as an effective method to prepare alternating multilayered structure. To understand the formation mechanism better and explore possible phase morphology for different blends under HSTWIM, the relationship between the morphology evolution of polymer blends based on polypropylene (PP) under HSTWIM and some intrinsic properties of polymer blends, including viscosity ratio, interfacial tension, and melt elasticity, is systematically investigated in this study. Blends based on PP containing polyethylene (PE), ethylene vinyl alcohol copolymer (EVOH), and polylactic acid (PLA) are used as examples. Compatibilizer has also been added into respective blends to alter their interfacial interaction. It is demonstrated that dispersed phase can be deformed into a layered-like structure if interfacial tension, viscosity ratio, and melt elasticity are relatively small. While some of these values are relatively large, these dispersed droplets are not easily deformed under HSTWIM, forming ellipsoidal or fiber-like structure. The addition of a moderate amount of compatibilizer into these blends is shown to be able to reduce interfacial tension and the size of dispersed phase, thus, allowing more deformation on the dispersed phase. Such a study could provide some guidelines on phase morphology control of immiscible polymer blends under shear during various processing methods.
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Affiliation(s)
- Yi Zhou
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University , Sichuan Sheng 610000, P.R. China
| | - Feilong Yu
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University , Sichuan Sheng 610000, P.R. China
| | - Hua Deng
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University , Sichuan Sheng 610000, P.R. China
| | - Yajiang Huang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University , Sichuan Sheng 610000, P.R. China
| | - Guangxian Li
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University , Sichuan Sheng 610000, P.R. China
| | - Qiang Fu
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University , Sichuan Sheng 610000, P.R. China
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Blakney AK, Simonovsky FI, Suydam IT, Ratner BD, Woodrow KA. Rapidly Biodegrading PLGA-Polyurethane Fibers for Sustained Release of Physicochemically Diverse Drugs. ACS Biomater Sci Eng 2016; 2:1595-1607. [PMID: 28989956 PMCID: PMC5630182 DOI: 10.1021/acsbiomaterials.6b00346] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Sustained release of physicochemically diverse drugs from electrospun fibers remains a challenge and precludes the use of fibers in many medical applications. Here, we synthesize a new class of polyurethanes with poly(lactic-co-glycolic acid) (PLGA) moieties that degrade faster than polyurethanes based on polycaprolactone. The new polymers, with varying hard to soft segment ratios and fluorobenzene pendant group content, were electrospun into nanofibers and loaded with four physicochemically diverse small molecule drugs. Polymers were characterized using GPC, XPS, and 19F NMR. The size and morphology of electrospun fibers were visualized using SEM, and drug/polymer compatibility and drug crystallinity were evaluated using DSC. We measured in vitro drug release, polymer degradation and cell-culture cytotoxicity of biodegradation products. We show that these newly synthesized PLGA-based polyurethanes degrade up to 65-80% within 4 weeks and are cytocompatible in vitro. The drug-loaded electrospun fibers were amorphous solid dispersions. We found that increasing the hard to soft segment ratio of the polymer enhances the sustained release of positively charged drugs, whereas increasing the fluorobenzene pendant content caused more rapid release of some drugs. In summary, increasing the hard segment or fluorobenzene pendant content of segmented polyurethanes containing PLGA moieties allows for modulation of physicochemically diverse drug release from electrospun fibers while maintaining a biologically relevant biodegradation rate.
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Affiliation(s)
- Anna K. Blakney
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, Washington 98195, United States
| | - Felix I. Simonovsky
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, Washington 98195, United States
| | - Ian T. Suydam
- Department of Chemistry, Seattle University, 901 12th Ave., Seattle, Washington 98122, United States
| | - Buddy D. Ratner
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, Washington 98195, United States
- Department of Chemical Engineering, University of Washington, 3720 15th Ave NE, Seattle, Washington 98195, United States
| | - Kim A. Woodrow
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, Washington 98195, United States
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Nair SS, McCullough EJ, Yadavalli VK, Wynne KJ. Integrated compositional and nanomechanical analysis of a polyurethane surface modified with a fluorous oxetane siliceous-network hybrid. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:12986-12995. [PMID: 25268217 DOI: 10.1021/la503216h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Investigating the surface characteristics of heterogeneous polymer systems is important for understanding how to better tailor surfaces and engineering specific reactions and desirable properties. Here we report on the surface properties for a blend consisting of a major component, a linear polyurethane or thermoplastic elastomer (TPU), and a minor component that is a hybrid network. The hybrid network consists of a fluorous polyoxetane soft block and a hydrolysis/condensation inorganic (HyCoin) network. Phase separation during coating formation results in surface concentration of the minor fluorous hybrid domain. The TPU is H12MDI/BD(50)-PTMO-1000 derived from bis(cyclohexylmethylene)-diisocyanate and butane diol (50 wt %) and poly(tetramethylene oxide). Surface modification results from a novel network-forming hybrid composed of poly(trifluoroethoxymethyl-methyl oxetane) diol) (3F) as the fluorous moiety end-capped with 3-isocyanatopropylriethoxysilane and bis(triethoxysilyl)ethane (BTESE) as a siliceous stabilizer. We use an integrated approach that combines elemental analysis of the near surface via X-ray photoelectron microscopy with surface mapping using atomic force microscopy that presents topographical and phase imaging along with nanomechanical properties. Overall, this versatile, high-resolution approach enabled unique insight into surface composition and morphology that led to a model of heterogeneous surfaces containing a range of constituents and properties.
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Affiliation(s)
- Sithara S Nair
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University 601 West Main Street, Richmond, Virginia 23284, United States
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Kurt P, Chakravorty A, Zeng X, Wynne KJ. Strongly amphiphilic wetting behavior for polyurethanes with polyoxetane soft blocks having –CF2H terminated side chains. POLYMER 2014. [DOI: 10.1016/j.polymer.2014.03.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Zhang C, Myers J, Chen Z. Elucidation of molecular structures at buried polymer interfaces and biological interfaces using sum frequency generation vibrational spectroscopy. SOFT MATTER 2013; 9:4738-4761. [PMID: 23710244 PMCID: PMC3661304 DOI: 10.1039/c3sm27710k] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Sum frequency generation (SFG) vibrational spectroscopy has been developed into an important technique to study surfaces and interfaces. It can probe buried interfaces in situ and provide molecular level structural information such as the presence of various chemical moieties, quantitative molecular functional group orientation, and time dependent kinetics or dynamics at such interfaces. This paper focuses on these three most important advantages of SFG and reviews some of the recent progress in SFG studies on interfaces related to polymer materials and biomolecules. The results discussed here demonstrate that SFG can provide important molecular structural information of buried interfaces in situ and in real time, which is difficult to obtain by other surface sensitive analytical techniques.
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Affiliation(s)
- Chi Zhang
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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Hankett JM, Liu Y, Zhang X, Zhang C, Chen Z. Molecular level studies of polymer behaviors at the water interface using sum frequency generation vibrational spectroscopy. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/polb.23221] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Zhang W, Fujiwara T, Taşkent H, Zheng Y, Brunson K, Gamble L, Wynne KJ. A Polyurethane Surface Modifier: Contrasting Amphiphilic and Contraphilic Surfaces Driven by block and random Soft Blocks having Trifluoroethoxymethyl and PEG Side Chains. MACROMOL CHEM PHYS 2012; 213. [PMID: 24204100 DOI: 10.1002/macp.201200075] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A conventional MDI-BD-PTMO polyurethane was modified using 2 wt.% polyurethanes (U) having copolyoxetane soft blocks with hydrophobic 3F, CF3CH2OCH2- and hydrophilic MEn, CH3O(CH2CH2O)nCH2-, n = 3, 7) side chains. In contrast to neat 3F-co-MEn-U, 2 wt.% 3F-co-MEn-U compositions have physically stable morphologies and wetting behavior. Surface composition (XPS) and amphiphilic or contraphilic wetting are controlled by the 3F-co-MEn polyoxetane soft block architecture and MEn side chain length. Importantly, θrec can be tuned for 2 wt.% 3F-co-MEn-U compositions independent of swelling, which is controlled by the bulk polyurethane. AFM imaging led to a new morphological model whereby fluorous/PEG-hard block nano-aggregates combine to form near surface features culminating in micron scale texturing.
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Affiliation(s)
- Wei Zhang
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA 23284
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10
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Sohn EH, Kim SH, Lee M, Song K. Surface characterization and liquid crystal alignment behavior of comb-like poly(oxyethylene)/poly(3-hexylthiophene) blend films. J Colloid Interface Sci 2012; 368:310-8. [DOI: 10.1016/j.jcis.2011.09.063] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Revised: 09/23/2011] [Accepted: 09/26/2011] [Indexed: 11/29/2022]
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11
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Wen Y, Liu Y, Guo Y, Yu G, Hu W. Experimental Techniques for the Fabrication and Characterization of Organic Thin Films for Field-Effect Transistors. Chem Rev 2011; 111:3358-406. [DOI: 10.1021/cr1001904] [Citation(s) in RCA: 214] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yugeng Wen
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Yunqi Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Yunlong Guo
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Gui Yu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Wenping Hu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
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Sohn EH, Kim BG, Chung JS, Kang H, Lee JC. Wettability of the morphologically and compositionally varied surfaces prepared from blends of well ordered comb-like polymer and polystyrene. J Colloid Interface Sci 2011; 354:650-61. [DOI: 10.1016/j.jcis.2010.10.068] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 10/29/2010] [Accepted: 10/30/2010] [Indexed: 11/27/2022]
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13
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Kim SH, Ribero FH, Rioux RM. Preface to the molecular surface chemistry and its applications special issue. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:16187-16189. [PMID: 20973576 DOI: 10.1021/la103676b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Affiliation(s)
- Seong H Kim
- Department of Chemical Engineering, The Pennsylvania State University, USA
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Shi Q, Ye S, Kristalyn C, Su Y, Jiang Z, Chen Z. Probing molecular-level surface structures of polyethersulfone/pluronic F127 blends using sum-frequency generation vibrational spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:7939-7946. [PMID: 18616306 DOI: 10.1021/la800570a] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We blended Pluronic F127 into polyethersulfone (PES) to improve surface properties of PES, which has been extensively used in biomaterial and other applications. The molecular surface structures of PES/Pluronic F127 blends have been investigated by sum-frequency generation (SFG) vibrational spectroscopy. The molecular orientation of surface functional groups of PES changed significantly when blended with a small amount of Pluornic F127. Pluronic F127 on the blend surface also exhibited different features upon contacting with water. The entanglement of PES chains with Pluronic F127 molecules rendered the blends with long-term surface stability in water in contrast to the situation where a layer of Pluronic F127 adsorbed on the PES surface. Atomic force microscopy (AFM) and quartz crystal microbalance (QCM) measurements were included to determine the relative amount of protein that adsorbed to the blend surfaces. The results showed a decreased protein adsorption amount with increasing Pluronic F127 bulk concentration. The correlations between polymer surface properties and detailed molecular structures obtained by SFG would provide insight into the designing and developing of biomedical polymers and functional membranes with improved fouling-resistant properties.
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Affiliation(s)
- Qing Shi
- Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
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MIYAMAE T, NISHIURA K, TAKAKI T. Characterization of the Organic-inorganic Hybrid Coating Surfaces Using Sum Frequency Generation Vibrational Spectroscopy. KOBUNSHI RONBUNSHU 2008. [DOI: 10.1295/koron.65.73] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Somorjai GA, York RL, Butcher D, Park JY. The evolution of model catalytic systems; studies of structure, bonding and dynamics from single crystal metal surfaces to nanoparticles, and from low pressure (<10−3Torr) to high pressure (>10−3Torr) to liquid interfaces. Phys Chem Chem Phys 2007; 9:3500-13. [PMID: 17612717 DOI: 10.1039/b618805b] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The material and pressure gap has been a long standing challenge in the field of heterogeneous catalysis and have transformed surface science and biointerfacial research. In heterogeneous catalysis, the material gap refers to the discontinuity between well-characterized model systems and industrially relevant catalysts. Single crystal metal surfaces have been useful model systems to elucidate the role of surface defects and the mobility of reaction intermediates in catalytic reactivity and selectivity. As nanoscience advances, we have developed nanoparticle catalysts with lithographic techniques and colloidal syntheses. Nanoparticle catalysts on oxide supports allow us to investigate several important ingredients of heterogeneous catalysis such as the metal-oxide interface and the influence of noble metal particle size and surface structure on catalytic selectivity. Monodispersed nanoparticle and nanowire arrays were fabricated for use as model catalysts by lithographic techniques. Platinum and rhodium nanoparticles in the 1-10 nm range were synthesized in colloidal solutions in the presence of polymer capping agents. The most catalytically active systems are employed at high pressure or at solid-liquid interfaces. In order to study the high pressure and liquid interfaces on the molecular level, experimental techniques with which we bridged the pressure gap in catalysis have been developed. These techniques include the ultrahigh vacuum system equipped with high pressure reaction cell, high pressure Sum Frequency Generation (SFG) vibration spectroscopy, High Pressure Scanning Tunneling Microscopy (HP-STM), and High Pressure X-ray Photoemission Spectroscopy (HP-XPS), and Quartz Crystal Microbalance (QCM). In this article, we overview the development of experimental techniques and evolution of the model systems for the research of heterogeneous catalysis and biointerfacial studies that can shed light on the long-standing issues of materials and pressure gaps.
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Affiliation(s)
- Gabor A Somorjai
- Department of Chemistry, University of California, Berkeley, CA 94720, USA.
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Chen Z. Understanding surfaces and buried interfaces of polymer materials at the molecular level using sum frequency generation vibrational spectroscopy. POLYM INT 2007. [DOI: 10.1002/pi.2201] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kweskin SJ, Komvopoulos K, Somorjai GA. Entropically Mediated Polyolefin Blend Segregation at Buried Sapphire and Air Interfaces Investigated by Infrared−Visible Sum Frequency Generation Vibrational Spectroscopy. J Phys Chem B 2005; 109:23415-8. [PMID: 16375314 DOI: 10.1021/jp053950l] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The segregation behavior of binary polymer blends at hydrophilic solid sapphire and air interfaces was investigated by infrared-visible sum frequency generation (SFG) vibrational spectroscopy. SFG spectra were collected from a bulk miscible blend consisting of identical molecular weight (approximately 54,000) and similar surface free energy (29-35 dyn/cm) components of atactic polypropylene (aPP) and aspecific poly(ethylene-co-propylene) rubber (aEPR). Characteristic CH resonances of the blend were contrasted with those of the individual components at both buried (sapphire/polymer) and free (air/polymer) interfaces. Preferential segregation of the aPP component was observed after annealing at both air/polymer and sapphire/polymer interfaces. SFG spectra revealed ordering of the polymer backbone segments with the methylene (CH2) groups perpendicular to the surface at the sapphire interface and the methyl (CH3) groups upright at the air interface. The SFG results indicate that the surface composition can be determined from the peak intensities that are characteristic of each component and that conformational entropy played a likely role in surface segregation. aPP occupied a smaller free volume at the surface because of a statistically smaller segment length (aPP is more flexible and has a shorter length). In addition, the high density of the ordered CH3 side branches enhanced the surface activity by allowing the long-chain backbone segments of aPP to order at the surface.
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Affiliation(s)
- S J Kweskin
- Department of Chemistry, University of California, Berkeley, California 94720, USA
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Koffas TS, Amitay-Sadovsky E, Kim J, Somorjai GA. Molecular composition and mechanical properties of biopolymer interfaces studied by sum frequency generation vibrational spectroscopy and atomic force microscopy. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2005; 15:475-509. [PMID: 15212330 DOI: 10.1163/156856204323005325] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Sum frequency generation (SFG) vibrational spectroscopy and atomic force microscopy (AFM) have been used to study the surface structure and surface mechanical behavior of biologically-relevant polymer systems. These techniques have emerged as powerful surface analytical tools to deduce structure/property relationships in situ, at both air/solid and air/liquid interfaces. SFG and AFM studies have been performed to understand how the surface properties of polymers are linked to polymer bulk compositions, changes in the ambient environment, or the degree of mechanical strain. Specifically, this review discusses (1) the macroscopic- and molecular-level tracking of small end groups attached to polyurethane blends, engineered to reduce blood clotting; (2) the role of ambient humidity on the surface mechanics of soft contact lenses possessing different water content in the bulk; (3) the affect of cyclic stretch on the molecular surface structure of polyurethane films, designed to mimic the mechanical deformation caused by heartbeat; and (4) the molecular ordering of functional groups at the polystyrene-protein interface. The correlation of spectroscopic and mechanical data by SFG and AFM is a powerful methodology to study and design materials with tailored surface properties.
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Affiliation(s)
- Telly S Koffas
- Department of Chemistry, University of California, Berkeley 94720, USA
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Abstract
Molecular level studies of the structure and mechanical properties of polymer surfaces have been carried out by sum frequency generation (SFG) surface vibrational spectroscopy and atomic force microscopy (AFM). The surfaces of different grades of polyethylene and polypropylene have been characterized-including during the glass transition and when mechanically stretched. Copolymers that have hard and soft segments with different glass transition temperatures show phase separation, an effect of hydrogen bonding between the hard and soft segments, that influences their adhesive and friction properties. AFM and SFG show that low surface energy additives migrate to the surface and alter the surface mechanical properties. Polymers, where the chemical nature of the end groups is different from the backbone, show surface segregation of the hydrophobic part of the chain in air and the hydrophilic part in water. Likewise, in miscible polymer blends, surface segregation of the more hydrophobic component in air and the more hydrophilic component in water is observed. This area of surface science requires increased attention because of the predominance of polymers as structural materials and as biomaterials.
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Affiliation(s)
- A Opdahl
- Department of Chemistry, University of California, Berkeley 94720, USA
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Chen Z, Ward R, Tian Y, Malizia F, Gracias DH, Shen YR, Somorjai GA. Interaction of fibrinogen with surfaces of end-group-modified polyurethanes: a surface-specific sum-frequency-generation vibrational spectroscopy study. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2002; 62:254-64. [PMID: 12209946 DOI: 10.1002/jbm.10075] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Fibrinogen adsorption on polyurethanes with different surface-modifying end groups (SMEs) has been studied with sum-frequency-generation vibrational spectroscopy (SFG). The results show very different protein adsorption properties for different SMEs on the same backbone polymer. Fibrinogen binds weakly on the hydrophilic backbone of a poly(dimethyl siloxane) (PDMS)-modified polyurethane surface but leaves the hydrophobic PDMS part untouched. On sulfonate end-group-modified (SO(3(-) )) polyurethane surfaces, fibrinogen adsorbs well. However, on poly(ethylene oxide) (PEO)-modified surfaces, it adsorbs poorly. The protein-resistant character of PEO is probably due to steric repulsion. This work demonstrates the utility of SFG in the study of protein adsorption on polymeric biomaterials at the molecular level and the ability of SMEs to mediate protein adsorption.
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Affiliation(s)
- Zhan Chen
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, USA
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Chen Z, Shen YR, Somorjai GA. Studies of polymer surfaces by sum frequency generation vibrational spectroscopy. Annu Rev Phys Chem 2002; 53:437-65. [PMID: 11972015 DOI: 10.1146/annurev.physchem.53.091801.115126] [Citation(s) in RCA: 350] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recently, sum frequency generation (SFG) vibrational spectroscopy has been developed into a powerful technique to study surfaces of polymer materials. This review summarizes the significant achievements in understanding surface molecular chemical structures of polymer materials obtained by SFG. It reviews in situ detection at the molecular level of surface structures of some common polymers in air, surface segregation of small end groups, polymer surface restructuring in water, and step-wise changed polymer blend surfaces. Studies of surface glass transition and surface structures modified by rubbing, plasma deposition, UV light irradiation, oxygen ion and radical irradiation, and wet etching are also discussed. SFG probing of polymer surfaces provides valuable insights into the relations between polymer surface structures and surface properties, which will assist in the design of polymer materials with desired surface properties.
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Affiliation(s)
- Zhan Chen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.
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Garrett JT, Siedlecki CA, Runt J. Microdomain Morphology of Poly(urethane urea) Multiblock Copolymers. Macromolecules 2001. [DOI: 10.1021/ma0102114] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Wang DA, Ji J, Feng LX. Surface Analysis of Poly(ether urethane) Blending Stearyl Poly(ethylene oxide) Coupling Polymer. Macromolecules 2000. [DOI: 10.1021/ma991412z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dong-an Wang
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, P.R. China
| | - Jian Ji
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, P.R. China
| | - Lin-Xian Feng
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, P.R. China
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26
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Raghavan D, Gu X, Nguyen T, VanLandingham M, Karim A. Mapping Polymer Heterogeneity Using Atomic Force Microscopy Phase Imaging and Nanoscale Indentation. Macromolecules 2000. [DOI: 10.1021/ma991206r] [Citation(s) in RCA: 200] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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27
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Wei X, Hong SC, Lvovsky AI, Held H, Shen YR. Evaluation of Surface vs Bulk Contributions in Sum-Frequency Vibrational Spectroscopy Using Reflection and Transmission Geometries. J Phys Chem B 2000. [DOI: 10.1021/jp9933929] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xing Wei
- Department of Physics, University of California, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Seok-Cheol Hong
- Department of Physics, University of California, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - A. I. Lvovsky
- Department of Physics, University of California, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Hermann Held
- Department of Physics, University of California, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Y. R. Shen
- Department of Physics, University of California, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
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28
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Chen Z, Ward R, Tian Y, Eppler AS, Shen YR, Somorjai GA. Surface Composition of Biopolymer Blends Biospan-SP/Phenoxy and Biospan-F/Phenoxy Observed with SFG, XPS, and Contact Angle Goniometry. J Phys Chem B 1999. [DOI: 10.1021/jp984502z] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zhan Chen
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, The Polymer Technology Group Inc., Berkeley, California 94710, and Department of Physics, University of California at Berkeley, Berkeley, California 94720
| | - Robert Ward
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, The Polymer Technology Group Inc., Berkeley, California 94710, and Department of Physics, University of California at Berkeley, Berkeley, California 94720
| | - Yuan Tian
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, The Polymer Technology Group Inc., Berkeley, California 94710, and Department of Physics, University of California at Berkeley, Berkeley, California 94720
| | - Aaron S. Eppler
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, The Polymer Technology Group Inc., Berkeley, California 94710, and Department of Physics, University of California at Berkeley, Berkeley, California 94720
| | - Y. R. Shen
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, The Polymer Technology Group Inc., Berkeley, California 94710, and Department of Physics, University of California at Berkeley, Berkeley, California 94720
| | - Gabor A. Somorjai
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, The Polymer Technology Group Inc., Berkeley, California 94710, and Department of Physics, University of California at Berkeley, Berkeley, California 94720
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