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Yanul, N.A.; Kirsh, Yu. E.; Ануфриева, Е. В.

doi:10.1023/a:1010180624147

Cited by 24 publications

(20 citation statements)

References 5 publications

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“…[34] Larger amounts of PNIPAM were deposited within films when the low critical solution temperature (LCST) of PNIPAM (32 8C) was approached and PNIPAM became less soluble in water. The behavior of other temperature-responsive polymers, PVME (LCST: $36 8C [35] ) and PVCL (LCST: $35 8C [36] ), was similar. [11] The bilayer film thickness increases with temperature even for films composed of PEO or PVPON and PAA [11] whose LCST is significantly higher than the temperature of the deposition solutions (for example, the LCST of PEO is 100-150 8C depending on the molecular weight [37] ).…”

Section: Self-assembly Conditions: Ph Ionic Strength and Temperaturementioning

confidence: 88%

Layer‐by‐Layer Hydrogen‐Bonded Polymer Films: From Fundamentals to Applications

2009

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Recent years have seen increasing interest in the construction of nanoscopically layered materials involving aqueous‐based sequential assembly of polymers on solid substrates. In the booming research area of layer‐by‐layer (LbL) assembly of oppositely charged polymers, self‐assembly driven by hydrogen bond formation emerges as a powerful technique. Hydrogen‐bonded (HB) LbL materials open new opportunities for LbL films, which are more difficult to produce than their electrostatically assembled counterparts. Specifically, the new properties associated with HB assembly include: 1) the ease of producing films responsive to environmental pH at mild pH values, 2) numerous possibilities for converting HB films into single‐ or two‐component ultrathin hydrogel materials, and 3) the inclusion of polymers with low glass transition temperatures (e.g., poly(ethylene oxide)) within ultrathin films. These properties can lead to new applications for HB LbL films, such as pH‐ and/or temperature‐responsive drug delivery systems, materials with tunable mechanical properties, release films dissolvable under physiological conditions, and proton‐exchange membranes for fuel cells. In this report, we discuss the recent developments in the synthesis of LbL materials based on HB assembly, the study of their structure–property relationships, and the prospective applications of HB LbL constructs in biotechnology and biomedicine.

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Section: Self-assembly Conditions: Ph Ionic Strength and Temperaturementioning

confidence: 88%

Layer‐by‐Layer Hydrogen‐Bonded Polymer Films: From Fundamentals to Applications

2009

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“…Therefore, we chose to also characterize the chain dynamics of water saturated complexes formed from deuterium-labeled poly(methacrylic acid), PMAA- d 3 , and a range of hydrogen-accepting polymers that have been used to produce pH responsive multilayer films and capsules. The polymers examined are listed, along with some thermal parameters, in Tables and . − Two of the hydrogen bond acceptor polymers, poly(ethylene oxide) (PEO) and poly(methyl vinyl ether) (PVME), are intrinsically more flexible with low glass transition temperatures, although it is well understood that water behaves as a plasticizer which further lowers the temperature of this transition when present.…”

Section: Introductionmentioning

confidence: 99%

Chain Dynamics of Water-Saturated Hydrogen-Bonded Polymer Complexes and Multilayers

2011

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The chain mobility of a series of hydrogen-bonded polymer complexes and multilayers were compared by variable temperature wide-line deuterium NMR spectroscopy. Poly-(methacrylic acid), deuterated at the methyl group, PMAA-d 3 , was complexed with five different hydrogen bond acceptor polymers-poly(ethylene oxide) (PEO), poly(acrylamide) (PAAM), poly(vinyl methyl ether) (PVME), poly(vinylpyrrolidone) (PVPon), and poly(vinylcaprolactam) (PVCL)-as well as with chitosan, where the interaction should be primarily ion pairing. The overall chain mobility of PMAA in its water-saturated complexes was observed to increase in the following order: PVCL < PVPon < chitosan < PVME < PAAM < PEO. For these polymer pairs, the same trend in chain mobility was also confirmed for the first few layers deposited on colloidal silica. The observed chain dynamics correlate well with the reported variation of the critical pH, bilayer thickness, and the permeability for multilayer films of the same polymers. In addition, the extent of chain interpenetration was demonstrated through the effect of a stabilizing primer layer on the chain mobility of the subsequently deposited weaker hydrogen-bonded multilayers.

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“…To further modulate the features of PVCL aqueous solutions, PVCL has been modified via copolymerization with N ‐vinylpyrrolidone (NVP),19 methacrylic acid,20 N ‐vinylimidazole,21 and alkyl acrylate derivations labeled with pyrene or naphthalene,22 as well as via grafting with PEO as an effective stabilizing agent 23. The studies of the properties of hydrophobically modified PVCL polymers suggest that the polymers can associate to form polymeric micelles via hydrophobic interactions in aqueous solution below the LCST 22, 24.…”

Section: Introductionmentioning

confidence: 99%

Thermo‐sensitive amphiphilic poly(N‐vinylcaprolactam) copolymers: synthesis and solution properties

Zhang

Liang

Meng

2009

Polymers for Advanced Techs

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Thermo-sensitive amphiphilic copolymers, PVCL-PTrpAMT and PVCL-PVP-PTrpAMT of hydrophilic N-vinylcaprolactam (VCL), N-vinylpyrrolidone (NVP), and hydrophobic N-t-Boc-tryptophanamido-N(-methacryl thioureas (TrpAMT) monomers, were synthesized and characterized by 1 H NMR, UV-spectroscopy, and GPC-MALLS. The cloud point (CP) measurement showed that hydrophobic PTrpAMT and hydrophilic PVP segments significantly altered the phase transition temperature of PVCL with comparable molecular weight in aqueous solution. The CP of PVP-PTrpAMT solution was 38.0-C, lower by 5.0-C than that of unmodified PVCL. In the presence of phosphate buffer saline (PBS), the CP value of the PVCL polymer decreased by $2.0-C in comparison to that of the aqueous solution. Fluorescent spectroscopy and TEM studies revealed that PVCL-PTrpAMT and PVCL-PVP-PTrpAMT self-assembled into the spherical micelles, 30-70 nm in diameter, at concentrations over their CMCs in an aqueous solution. Cytotoxicity tests demonstrated that the PVCL copolymers were not harmful to cell viability, which may favor the use of the copolymers as potential thermo-sensitive polymers in pharmaceutical applications. Copyright ß 2009 John Wiley & Sons, Ltd.Keywords: amphiphiles; self-assembly; solution properties; thermo-sensitive; N-vinylcaprolactam INTRODUCTIONThermo-responsive amphiphilic copolymers have recently attracted extensive attention because of both their intrinsic properties [1][2][3] and their wide range of potential applications in medicine, [4] biotechnology, [5] ecology, [6] and pharmacology. [7] An aqueous solution of this type of polymer is characterized by a phase separation upon heating, and the system exhibits a lower critical solution temperature (LCST). [8,9] At a low temperature, the solution is homogeneous, but when the temperature exceeds a certain value called the cloud point (CP) of the mixture, a macroscopic phase separation occurs. The LCST corresponds to the minimum of the phase separation curve. [10,11] Belonging to the category of thermo-sensitive polymers, poly(N-vinylcaprolactam) (PVCL) has recently attracted a great deal of interest. [12][13][14][15] PVCL is a well-known polymer exhibiting the LCST behavior. It shows a dissolution/precipitation transition in water at temperatures close to body temperature. [16] Also, PVCL is stable against hydrolysis, non-toxic, and biocompatible. [17] These properties make it an interesting candidate for biomedical applications. [5,18] To further modulate the features of PVCL aqueous solutions, PVCL has been modified via copolymerization with N-vinylpyrrolidone (NVP), [19] methacrylic acid, [20] N-vinylimidazole, [21] and alkyl acrylate derivations labeled with pyrene or naphthalene, [22] as well as via grafting with PEO as an effective stabilizing agent. [23] The studies of the properties of hydrophobically modified PVCL polymers suggest that the polymers can associate to form polymeric micelles via hydrophobic interactions in aqueous solution below the LCST. [22,24] But to the best of our knowledge, the ...

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Untitled

Cited by 24 publications

References 5 publications

Layer‐by‐Layer Hydrogen‐Bonded Polymer Films: From Fundamentals to Applications

Layer‐by‐Layer Hydrogen‐Bonded Polymer Films: From Fundamentals to Applications

Chain Dynamics of Water-Saturated Hydrogen-Bonded Polymer Complexes and Multilayers

Thermo‐sensitive amphiphilic poly(N‐vinylcaprolactam) copolymers: synthesis and solution properties

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