Microcalorimetric Study of Aqueous Solution of a Thermoresponsive Polymer, poly(N-vinylisobutyramide) (PNVIBA)

Kunugi, Shigeru; Tada, Tomoko; Tanaka, Naoki; Yamamoto, Katsuhiro; Akashi, Mitsuru

doi:10.1295/polymj.34.383

Cited by 33 publications

(29 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 8 shows T cp s vs. polymer molecular weights for well-defined PNIPAM samples with different end-groups. For hydrophilic endgroups such as amino, the polymers showed inverse molecular weight dependence of the T cp , in good agreement with previous studies [28][29][30][31][32]. However, the T cp was found to be directly dependent upon polymer molecular weight for hydrophobic end-groups.…”

Section: Thermoresponsivity Of Pnipams Before and After Click Reactionsupporting

confidence: 91%

“…The bisalkynelinked PNIPAM that was designed as no end-group effect reference gave the smallest molecular weight dependence among the three series studied here. As mentioned above, previous studies of PNIPAM and other thermoresponsive polymers have demonstrated the LCST to be independent [32][33][34]45], directly dependent [10,26], or inversely dependent [17,[27][28][29][30][31]46,47] upon polymer molecular weight. LCSTs are expected to be decreased with increasing molecular weight on the basis of the changes in the polymer-solvent interaction [48,49].…”

Section: Thermoresponsivity Of Pnipams Before and After Click Reactionmentioning

confidence: 78%

“…However, the end-effect contribution is significantly dependent on the polymer molecular weight as well as its polydispersity [23]. Previous studies have demonstrated that the LCST of PNIPAM with monofunctional end-group was directly dependent [10,27], inversely dependent [28][29][30][31][32], or independent [33][34][35] on the molecular weight of PNIPAM, respectively. These different results may be attributed to different polymer end-groups as well as polydispersity, or different techniques for measuring LCSTs.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Well-defined poly(N-isopropylacrylamide) with a bifunctional end-group: synthesis, characterization, and thermoresponsive properties

Liu

Liao

Yang

et al. 2012

Designed Monomers and Polymers

View full text Add to dashboard Cite

(2013) Well-defined poly(N-isopropylacrylamide) with a bifunctional end-group: synthesis, characterization, and thermoresponsive properties, Designed Monomers and Polymers, 16:5, 465-474, DOI: 10.1080/15685551.2012 In this study, well-defined poly(N-isopropylacrylamide) (PNIPAM) with a bisalkyne end-group was synthesized by reversible addition-fragmentation chain transfer polymerization using 2-(2-(ethylthiocarbonothioylthio)-2-methylpropanoyl-oxy)ethyl 3,5-bis(prop-2-ynyloxy) benzoate (EMEB) as the chain transfer agent. The molecular weight and polydispersity index of polymer was determined by gel permeation chromatography (GPC). The linear increase in molecular weight with conversion, unimodal, and almost symmetrical peak in GPC trace together with low polydispersity indicated the controlled polymerization process of NIPAM mediated by EMEB. Subsequently, the Cu(I)-catalyzed [3 + 2] Huisgen cycloaddition between the end-group of polymer and azide derivatives was carried out to produce PNIPAM, in which the bisfunctional end-group was modified with phenyl, octyl, amido, and hydroxyl groups. After completing the click reaction, the structure of the polymer was characterized carefully by Fourier transform infrared spectroscopy (FTIR), 1 H NMR, and Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS), indicating the complete consumption of alkyne end-groups. In addition, almost no change in molecular weight as well as the polydispersity was observed by comparison with the GPC traces of polymers before and after click reaction. The cloud point temperatures (T cp s) of the resulting PNIPAM derivatives in aqueous solution were investigated in detail by dynamic light scattering. The results showed that the values of T cp were ranged from 22 to 38°C, which depended largely on end-groups as well as the polymer molecular weights.

show abstract

Section: Thermoresponsivity Of Pnipams Before and After Click Reactionsupporting

confidence: 91%

Section: Thermoresponsivity Of Pnipams Before and After Click Reactionmentioning

confidence: 78%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Well-defined poly(N-isopropylacrylamide) with a bifunctional end-group: synthesis, characterization, and thermoresponsive properties

Liu

Liao

Yang

et al. 2012

Designed Monomers and Polymers

View full text Add to dashboard Cite

show abstract

“…Inomata et al [32] as well as Kunugi et al [33] performed lightscattering experiments in order to extract information about the spinodal decomposition of the aqueous solution of PNIPAM.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamics of aqueous solutions containing poly (N-isopropylacrylamide)

Poschlad

Enders

2011

The Journal of Chemical Thermodynamics

View full text Add to dashboard Cite

“…The corresponding energy is ÀT c ÁS ¼ 3:62 Â 10 6 J mol À1 . The hydration entropy loss per monomer was measured for free PNIPAM chains in water and is $10 J K À1 mol À1 [17]. Thus, if chains were to behave as free chains, we would have $10 3 equivalent monomers per particle.…”

mentioning

confidence: 99%

Quantifying the Reversible Association of Thermosensitive Nanoparticles

et al. 2011

View full text Add to dashboard Cite

Under many conditions, biomolecules and nanoparticles associate by means of attractive bonds, due to hydrophobic attraction. Extracting the microscopic association or dissociation rates from experimental data is complicated by the dissociation events and by the sensitivity of the binding force to temperature (T). Here we introduce a theoretical model that combined with light-scattering experiments allows us to quantify these rates and the reversible binding energy as a function of T. We apply this method to the reversible aggregation of thermoresponsive polystyrene/poly(N-isopropylacrylamide) core-shell nanoparticles, as a model system for biomolecules. We find that the binding energy changes sharply with T, and relate this remarkable switchable behavior to the hydrophobic-hydrophilic transition of the thermosensitive nanoparticles.The association and self-organization of biomolecules [1] and nanoparticles [2] play a fundamental role in many physiological processes [3], such as protein amyloid formation which is responsible for neuro-degenerative diseases [4], as well as in technological processes. In particular the assembly of nanoparticles has become a key step in the synthesis of nanomaterials with new optical and mechanical properties [5]. In order to understand and control all these association processes, it is essential to understand and control the association kinetics [3,4]. This is challenging in the case of biomolecules and nanoparticles where often the microscopic binding energy, which directly determines the rate of dimer formation, is comparable to the thermal energy k B T. This poses two major difficulties: (i) the experimental detection of the binding energy has to be accurate down to the k B T scale, and (ii) the association kinetics is affected by dissociation events [6,7] since the binding energy is comparable with the average kinetic energy of the particles/molecules. It has been recently shown that a clear understanding of protein aggregation under physiological conditions cannot be achieved without the understanding of aggregate dissociation [7]. A further complication arises from the fact that the binding energy can be very sensitive to changes of the solution parameters, such as T and pH [3].In this Letter we propose a detection strategy that can overcome many of the difficulties to date in extracting quantitative information about the intrinsic rates of association and dissociation processes. The essence of the strategy is to combine a kinetic model with the analysis of dynamic light scattering (DLS) data of aggregation kinetics. Dynamic light scattering has proven to be a reliable tool for analyzing irreversible aggregation [8].Here we show that it can be used for measuring reversible processes as well, but the data analysis requires a new model fully accounting for dissociation processes. Here we introduce such a model and demonstrate its applicability in light scattering experiments of thermosensitive nanoparticles in aqueous suspension. We also show how to quantify the T-dependent int...

show abstract

Microcalorimetric Study of Aqueous Solution of a Thermoresponsive Polymer, poly(N-vinylisobutyramide) (PNVIBA)

Cited by 33 publications

References 24 publications

Well-defined poly(N-isopropylacrylamide) with a bifunctional end-group: synthesis, characterization, and thermoresponsive properties

Well-defined poly(N-isopropylacrylamide) with a bifunctional end-group: synthesis, characterization, and thermoresponsive properties

Thermodynamics of aqueous solutions containing poly (N-isopropylacrylamide)

Quantifying the Reversible Association of Thermosensitive Nanoparticles

Contact Info

Product

Resources

About