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Grigoreva A, Tarankova K, Zamyshlyayeva O, Zaitsev S. Aggregation behaviour of poly(fluoro(meth)acrylate)-block-poly(acrylic acid) copolymers at the air /water interface. JOURNAL OF POLYMER RESEARCH 2021. [DOI: 10.1007/s10965-021-02629-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Li J, Du Y, Su H, Cheng S, Zhou Y, Jin Y, Qi XR. Interfacial properties and micellization of triblock poly(ethylene glycol)-poly( ε-caprolactone)-polyethyleneimine copolymers. Acta Pharm Sin B 2020; 10:1122-1133. [PMID: 32642417 PMCID: PMC7332608 DOI: 10.1016/j.apsb.2020.01.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 10/24/2019] [Accepted: 11/11/2019] [Indexed: 01/30/2023] Open
Abstract
This study aimed to explore the link between block copolymers' interfacial properties and nanoscale carrier formation and found out the influence of length ratio on these characters to optimize drug delivery system. A library of diblock copolymers of PEG-PCL and triblock copolymers with additional PEI (PEG-PCL-PEI) were synthesized. Subsequently, a systematic isothermal investigation was performed to explore molecular arrangements of copolymers at air/water interface. Then, structural properties and drug encapsulation in self-assembly were investigated with DLS, SLS and TEM. We found the additional hydrogen bond in the PEG-PCL-PEI contributes to film stability upon the hydrophobic interaction compared with PEG-PCL. PEG-PCL-PEI assemble into smaller micelle-like (such as PEG-PCL4006-PEI) or particle-like structure (such as PEG-PCL8636-PEI) determined by their hydrophilic and hydrophobic block ratio. The distinct structural architectures of copolymer are consistent between interface and self-assembly. Despite the disparity of constituent ratio, we discovered the arrangement of both chains guarantees balanced hydrophilic-hydrophobic ratio in self-assembly to form stable construction. Meanwhile, the structural differences were found to have significant influence on model drugs incorporation including docetaxel and siRNA. Taken together, these findings indicate the correlation between molecular arrangement and self-assembly and inspire us to tune block compositions to achieve desired nanostructure and drug loading.
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Key Words
- AFM, atomic force microscope
- Amin, critical molecular area
- Block copolymers
- CMC, critical micelle concentration
- DLS, dynamic light scattering
- DTX, docetaxel
- GPC, gel permeation chromatography
- LB, Langmuir–Blodgett
- Langmuir films
- Molecular arrangement
- Nagg, polymer aggregation number
- Nanostructure
- Np, nano-assembly numbers
- PCL, poly(ε-caprolactone)
- PDI, polydispersity
- PEG, poly(ethylene glycol)
- PEI, polyethyleneimine
- Rg, gyration radius
- Rh, hydrodynamic radius
- SLS, static light scattering
- Self-assembly
- TEM, transmission electron microscope
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Affiliation(s)
- Ji Li
- Key Laboratory of Molecular Pharmaceutics and New Drug Delivery System, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Yitian Du
- Key Laboratory of Molecular Pharmaceutics and New Drug Delivery System, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Haitao Su
- Key Laboratory of Molecular Pharmaceutics and New Drug Delivery System, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Shixuan Cheng
- Key Laboratory of Molecular Pharmaceutics and New Drug Delivery System, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Yanxia Zhou
- Key Laboratory of Molecular Pharmaceutics and New Drug Delivery System, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Yiguang Jin
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Xian-Rong Qi
- Key Laboratory of Molecular Pharmaceutics and New Drug Delivery System, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
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Hasan N, Schwieger C, Tee HT, Wurm FR, Busse K, Kressler J. Crystallization of a polyphosphoester at the air-water interface. Eur Polym J 2018. [DOI: 10.1016/j.eurpolymj.2018.03.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Molecular arrangement of symmetric and non-symmetric triblock copolymers of poly(ethylene oxide) and poly(isobutylene) at the air/water interface. J Colloid Interface Sci 2015; 437:80-89. [PMID: 25313470 DOI: 10.1016/j.jcis.2014.09.050] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Revised: 09/12/2014] [Accepted: 09/15/2014] [Indexed: 12/16/2022]
Abstract
The behavior of a series of amphiphilic triblock copolymers of poly(ethylene oxide) (PEO) and poly(isobutylene) (PIB); including both symmetric (same degree of polymerization (DP) of the terminal PEO blocks) PEOm-b-PIBn-b-PEOm and non-symmetric (different DP of the terminal PEO blocks) PEOm-b-PIBn-b-PEOz, is investigated at the air/water interface by measuring surface pressure vs mean molecular area isotherms (π vs mmA), Langmuir-Blodgett (LB) technique, and infrared reflection-absorption spectroscopy (IRRAS). The block copolymer (PEO32-b-PIB160-b-PEO32) with longer PEO segments forms a stable monolayer and the isotherm reveals a pseudo-plateau starting at π∼5.7 mN/m, also observed in the IRRAS, which is assigned to the pancake-to-brush transition related to the PEO dissolution into the subphase and subsequent PEO brush dehydration. Another plateau is observed at π∼40 mN/m, which is attributed to the film collapse due to multilayer formation. The pancake-to-brush transition could not be observed for samples with smaller PEO chains. The isotherms for block copolymers, with short PEO chains, both symmetric (PEO3-b-PIBn-b-PEO3) and non-symmetric (PEO12-b-PIBn-b-PEO3), reveal another transition at π∼20-25 mN/m. This is interpreted to be due to the conformational transition from a folded state where the middle PIB block is anchored to the water surface at both ends by the terminal hydrophilic segments to an unfolded state with PIB anchored to the water surface at one end. It is assumed that this transition involves the removal of PEO3 chains from the water surface in case of non-symmetric PEO12-b-PIB85-b-PEO3 and in case of symmetric, probably one PEO3 of each PEO3-b-PIB85-b-PEO3 chain. Because of the weaker interaction of the short PEO3 chains with the water surface as compared with the relatively longer PEO12 chains, the film of PEO3-b-PIB85-b-PEO3 collapses at much lower surface pressure after the transition as compared with the PEO12-b-PIB85-b-PEO3. The AFM images reveal the formation of microdomains of almost uniform height (6-7 nm) in LB films of PEO3-b-PIB85-b-PEO3 and PEO12-b-PIB85-b-PEO3 after transferring onto silicon surfaces. These domains are assumed to be the mesomorphic domains of ordered and folded PIB chains.
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Li Z, Ma X, Zang D, Guan X, Zhu L, Liu J, Chen F. Interfacial rheology and aggregation behaviour of amphiphilic CBABC-type pentablock copolymers at the air–water interface: effects of block ratio and chain length. RSC Adv 2015. [DOI: 10.1039/c5ra08109b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The interfacial rheology, aggregation behaviour and packing model of the structure evolution of three amphiphilic CBABC-type pentablock copolymers were investigated at the air–water interface.
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Affiliation(s)
- Zhiguang Li
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Xiaoyan Ma
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Duyang Zang
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Xinghua Guan
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Lin Zhu
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Jinshu Liu
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Fang Chen
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
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Scholtysek P, Li Z, Kressler J, Blume A. Interactions of DPPC with semitelechelic poly(glycerol methacrylate)s with perfluoroalkyl end groups. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:15651-62. [PMID: 23046205 DOI: 10.1021/la3028226] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Semitelechelic poly(glycerol methacrylate)s having a perfluoroalkyl end group (PGMA(n)-F(9)) were synthesized by ATRP. The interactions of these polymers with different degrees of polymerization with chiral or racemic dipalmitoylphosphatidylcholine (l-DPPC, d-DPPC, or rac-DPPC) monolayers at the air/water interface were studied. Langmuir trough measurements coupled with epifluorescence microscopy allowed for the observation of domain formation within the coexistence region of liquid-expanded (LE) and liquid-condensed (LC) states of DPPC in mixed DPPC-polymer films prepared by spreading a solution of both compounds in the same organic solvent (cospread films). Because of the incorporation of PGMA(n)-F(9) polymers into the LE phase and their line-active behavior, a formation of novel types of domains could be observed. During compression, a thinning out of the tips of two- to six-lobed flowerlike domain structures and consecutive spiral formation appeared for l- and d-DPPC within the two-phase coexistence region (LE/LC) of the monolayer. When rac-DPPC was used, symmetrical stripe formation was induced at the vertices of the domains and fingerprint-like structures were created by convection-inducing movements of the domains at the air/water interface. Additional investigations of the interaction of PGMA(n)-F(9) with DPPC vesicles using differential scanning calorimetry (DSC) supported the finding on the monolayer system that the incorporation of the polymers into the lipid monolayers is not solely driven by the perfluoroalkyl chain but significantly by the hydrophilic polymer part. Apparently, interactions of the PGMA chain with the lipid headgroups are important as the interactions increase with the elongation of the polymer chain, indicating that the polymer also has hydrophobic character.
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Affiliation(s)
- Peggy Scholtysek
- Institute of Chemistry, Martin-Luther University Halle-Wittenberg, Saale, Germany
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Samuel AZ, Ramakrishnan S. Janus Hybramers: Self-Adapting Amphiphilic Hyperbranched Polymers. Macromolecules 2012. [DOI: 10.1021/ma2022277] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ashok Zachariah Samuel
- Department of Inorganic
and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - S. Ramakrishnan
- Department of Inorganic
and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
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Amado E, Kressler J. Interactions of amphiphilic block copolymers with lipid model membranes. Curr Opin Colloid Interface Sci 2011. [DOI: 10.1016/j.cocis.2011.07.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Reuter S, Hofmann AM, Busse K, Frey H, Kressler J. Langmuir and Langmuir-Blodgett films of multifunctional, amphiphilic polyethers with cholesterol moieties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:1978-1989. [PMID: 21175221 DOI: 10.1021/la104274d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Langmuir films of multifunctional, hydrophilic polyethers containing a hydrophobic cholesterol group (Ch) were studied by surface pressure-mean molecular area (π-mmA) measurements and Brewster angle microscopy (BAM). The polyethers were either homopolymers or diblock copolymers of linear poly(glycerol) (lPG), linear poly(glyceryl glycidyl ether) (lPGG), linear poly(ethylene glycol) (lPEG), or hyperbranched poly(glycerol) (hbPG). Surface pressure measurements revealed that the homopolymers lPG and hbPG did not stay at the water surface after spreading and solvent evaporation, in contrast to lPEG. Because of the incorporation of the Ch group in the polymer structure, stable Langmuir films were formed by Ch-lPG(n), Ch-lPGG(n), and Ch-hbPG(n). The Ch-hbPG(n), Ch-lPEG(n), Ch-lPEG(n)-b-lPG(m), Ch-lPEG(n)-b-lPGG(m), and Ch-lPEG(n)-b-hbPG(m) systems showed an extended plateau region assigned to a phase transition involving the Ch groups. Typical hierarchically ordered morphologies of the LB films on hydrophilic substrates were observed for all Ch-initiated polymers. All LB films showed that Ch of the Ch-initiated homopolymers is able to crystallize. This strong tendency of self-aggregation then triggers further dewetting effects of the respective polyether entities. Fingerlike morphologies are observed for Ch-lPEG(69), since the lPEG(69) entity is able to undergo crystallization after transfer onto the silicon substrate.
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Affiliation(s)
- Sascha Reuter
- Department of Chemistry, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
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Hussain H, Amado E, Kressler J. Functional Polyether-based Amphiphilic Block Copolymers Synthesized by Atom-transfer Radical Polymerization. Aust J Chem 2011. [DOI: 10.1071/ch11147] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This review deals with the synthesis, physical properties, and applications of amphiphilic block copolymers based on hydrophilic poly(ethylene oxide) (PEO) or hydrophobic poly(propylene oxide) (PPO). Oligomeric PEO and PPO are frequently functionalized by converting their OH end groups into macroinitiators for atom-transfer radical polymerization. They are then used to generate additional blocks as part of complex copolymer architectures. Adding hydrophobic and hydrophilic blocks, respectively, leads to polymers with amphiphilic character in water. They are surface active and form micelles above a critical micellization concentration. Together with recent developments in post-polymerization techniques through quantitative coupling reactions (‘click’ chemistry) a broad variety of tailored functionalities can be introduced to the amphiphilic block copolymers. Examples are outlined including stimuli responsiveness, membrane penetrating ability, formation of multi-compartmentalized micelles, etc.
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Naolou T, Busse K, Kressler J. Synthesis of Well-Defined Graft Copolymers by Combination of Enzymatic Polycondensation and “Click” Chemistry. Biomacromolecules 2010; 11:3660-7. [DOI: 10.1021/bm1011085] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Toufik Naolou
- Martin Luther University Halle-Wittenberg, Department of Chemistry, D-06099 Halle (Saale), Germany
| | - Karsten Busse
- Martin Luther University Halle-Wittenberg, Department of Chemistry, D-06099 Halle (Saale), Germany
| | - Jörg Kressler
- Martin Luther University Halle-Wittenberg, Department of Chemistry, D-06099 Halle (Saale), Germany
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Rother M, Barqawi H, Pfefferkorn D, Kressler J, Binder WH. Synthesis and Organization of Three-Arm-Star PIB-PEO Block Copolymers at the Air/Water Interface: Langmuir- and Langmuir-Blodgett Film Investigations. MACROMOL CHEM PHYS 2009. [DOI: 10.1002/macp.200900435] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Li Z, Schön V, Huber P, Kressler J, Busse K. Comparison of the Monolayer Formation of Fluorinated and Nonfluorinated Amphiphilic Block Copolymers at the Air−Water Interface. J Phys Chem B 2009; 113:11841-7. [DOI: 10.1021/jp905016s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zheng Li
- Institute of Physical Chemistry, Department of Chemistry, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany, and Faculty of Physics and Mechatronics Engineering, Department of Engineering Physics, Saarland University, D-66123 Saarbrücken, Germany
| | - Volker Schön
- Institute of Physical Chemistry, Department of Chemistry, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany, and Faculty of Physics and Mechatronics Engineering, Department of Engineering Physics, Saarland University, D-66123 Saarbrücken, Germany
| | - Patrick Huber
- Institute of Physical Chemistry, Department of Chemistry, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany, and Faculty of Physics and Mechatronics Engineering, Department of Engineering Physics, Saarland University, D-66123 Saarbrücken, Germany
| | - Jörg Kressler
- Institute of Physical Chemistry, Department of Chemistry, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany, and Faculty of Physics and Mechatronics Engineering, Department of Engineering Physics, Saarland University, D-66123 Saarbrücken, Germany
| | - Karsten Busse
- Institute of Physical Chemistry, Department of Chemistry, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany, and Faculty of Physics and Mechatronics Engineering, Department of Engineering Physics, Saarland University, D-66123 Saarbrücken, Germany
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Adsorption properties of oligo(fluorooxetane)-b-poly(ethylene oxide)-b-oligo(fluorooxetane) triblock copolymers at the air–water interface: Comparison of hydroxyl and acetate end groups. J Colloid Interface Sci 2009; 336:40-5. [DOI: 10.1016/j.jcis.2009.03.043] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Revised: 03/25/2009] [Accepted: 03/25/2009] [Indexed: 11/19/2022]
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Li H, Sachsenhofer R, Binder WH, Henze T, Thurn-Albrecht T, Busse K, Kressler J. Hierarchical organization of poly(ethylene oxide)-block-poly(isobutylene) and hydrophobically modified Fe(2)O(3) nanoparticles at the air/water interface and on solid supports. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:8320-8329. [PMID: 19441824 DOI: 10.1021/la900549h] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Langmuir monolayers and Langmuir-Blodgett (LB) film morphologies of block copolymers and hydrophobically modified iron oxide nanoparticles were studied by surface pressure-mean molecular area (pi-mmA) measurements and by tapping mode atomic force microscopy (AFM). The amphiphilic diblock copolymers consisted of a hydrophilic poly(ethylene oxide) (PEO) block and a hydrophobic poly(isobutylene) (PIB) block. The pi-mmA isotherm of PEO(97)-b-PIB(37) (the subscripts refer to the respective degrees of polymerization) at the air/water interface had an extended plateau reflecting the extension of PEO chains into the water subphase at a surface pressure of 10 mN.m(-1), which is absent for the more hydrophobic PEO(19)-b-PIB(130). Iron oxide (Fe(2)O(3)) nanoparticles capped with oleic acid ligands as the shell were dispersed in the amphiphilic block copolymers at the air/water interface to prevent macroscopic aggregation of the particles. When the nanoparticles were mixed with PEO(97)-b-PIB(37), using a particle to polymer chain ratio of 1:100, macroscopic aggregation of the nanoparticles was not observed, and the pi-mmA isotherm was dominated by PEO(97)-b-PIB(37). Monolayers of block copolymers were transferred at different surface pressures from the air/water interface to hydrophilic silicon substrates using the Langmuir-Blodgett technique. The AFM images of PEO(97)-b-PIB(37) LB films depicted not only the typical finger-like morphology of the crystallized PEO blocks but also PIB blocks arranged in vertical columns growing perpendicular to the substrate surface. The columns are characteristic for PEO(19)-b-PIB(130) LB films after transfer at high surface pressures and can be assigned to a mesomorphic PIB phase with ordered chains. Finally, it was observed that small clusters of a few Fe(2)O(3) nanoparticles occupy the top of PIB phases after compression and transfer of the block copolymer nanoparticle mixtures to solid supports.
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Affiliation(s)
- Hangsheng Li
- Martin Luther University Halle-Wittenberg, D-06099 Halle, Germany
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Amado E, Blume A, Kressler J. Novel non-ionic block copolymers tailored for interactions with phospholipids. REACT FUNCT POLYM 2009. [DOI: 10.1016/j.reactfunctpolym.2008.12.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Martinelli E, Agostini S, Galli G, Chiellini E, Glisenti A, Pettitt ME, Callow ME, Callow JA, Graf K, Bartels FW. Nanostructured films of amphiphilic fluorinated block copolymers for fouling release application. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:13138-13147. [PMID: 18928304 DOI: 10.1021/la801991k] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
New amphiphilic block copolymers S nSz m consisting of blocks with varied degrees of polymerization, n and m, of polystyrene, S, and polystyrene carrying an amphiphilic polyoxyethylene-polytetrafluoroethylene chain side-group, Sz, were prepared by controlled atom transfer radical polymerization (ATRP). The block copolymers, either alone or in a blend with commercial SEBS (10 wt% SEBS), were spin-coated in thinner films (200-400 nm) on glass and spray-coated in thicker films ( approximately 500 nm) on a SEBS underlayer (150-200 microm). Angle-resolved X-ray photoelectron spectroscopy (XPS) measurements proved that at any photoemission angle, varphi, the atomic ratio F/C was larger than that expected from the known stoichiometry. Consistent with the enrichment of the outer film surface (3-10 nm) in F content, the measured contact angles, theta, with water (theta w > or = 107 degrees ) and n-hexadecane (theta h > or = 64 degrees ) pointed to the simultaneous hydrophobic and lipophobic character of the films. The film surface tension gamma S calculated from the theta values was in the range 13-15 mN/m. However, the XPS measurements on the "wet" films after immersion in water demonstrated that the film surface underwent reconstruction owing to its amphiphilic nature, thereby giving rise to a more chemically heterogeneous structure. The atomic force microscopy (AFM) images (tapping mode/AC mode) revealed well-defined morphological features of the nanostructured films. Depending on the chemical composition of the block copolymers, spherical (ca. 20 nm diameter) and lying cylindrical (24-29 nm periodicity) nanodomains of the S discrete phase were segregated from the Sz continuous matrix (root-mean-square, rms, roughness approximately 1 nm). After immersion in water, the underwater AFM patterns evidenced a transformation to a mixed surface structure, in which the nanoscale heterogeneity and topography (rms = 1-6 nm) were increased. The coatings were subjected to laboratory bioassays to explore their intrinsic ability to resist the settlement and reduce the adhesion strength of two marine algae, viz., the macroalga (seaweed) Ulva linza and the unicellular diatom Navicula perminuta. The amphiphilic nature of the copolymer coatings resulted in distinctly different performances against these two organisms. Ulva adhered less strongly to the coatings richer in the amphiphilic polystyrene component, percentage removal being maximal at intermediate weight contents. In contrast, Navicula cells adhered less strongly to coatings with a lower weight percentage of the amphiphilic side chains. The results are discussed in terms of the changes in surface structure caused by immersion and the effects such changes may have on the adhesion of the test organisms.
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Affiliation(s)
- Elisa Martinelli
- Dipartimento di Chimica e Chimica Industriale and UdR Pisa INSTM, Universita di Pisa, via Risorgimento 35, 56126 Pisa, Italy
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Liu L, Kim JK, Lee M. Interfacial Organization of Y-Shaped Rod-Coil Molecules Packed into Cylindrical Nanoarchitectures. Chemphyschem 2008; 9:1585-92. [DOI: 10.1002/cphc.200800124] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kyeremateng SO, Amado E, Blume A, Kressler J. Synthesis of ABC and CABAC Triphilic Block Copolymers by ATRP Combined with ‘Click’ Chemistry. Macromol Rapid Commun 2008. [DOI: 10.1002/marc.200800058] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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