Spectroscopic Observations of Surfactant-Induced Conformational Changes of a Water-Soluble Polysilane

Seki, Takahiro; Tohnai, Atsushi; Tamaki, Takashi; Kaito, Akira

doi:10.1021/ma960259v

Cited by 21 publications

(17 citation statements)

References 18 publications

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“…1 H NMR and 13 C NMR spectra of the polymers were obtained with a Bruker Advance III 400 MHz spectrometer, 29 Si NMR spectra of the polymers were obtained by employing a Bruker Advance III 500 MHz spectrometer. FT-IR spectra were recorded on a Nicolet IS10 in the region of 4000-400 cm À1 using KBr pellets or film.…”

Section: Characterizationmentioning

confidence: 99%

“…1 H NMR (400 MHz, CDCl 3 ,d, ppm): À0.8 to 0.6 (Si-CH 3 ), 6.4-7.4 (Si-C 6 H 5 ). 13 C NMR (100 MHz, 29 Si NMR (100 MHz, CDCl 3 , d, ppm): À41.2 to À36.6 (-(SiPhMe)-).…”

Section: Preparation Of Polysilanementioning

confidence: 99%

“…The resonance peak at 170.6 ppm corresponding to the carbonyl group in polyethyleneglycol 5 moved to 174.7 ppm in polymer 6 demonstrating the completion of polymerization of acrylate. 29 Si NMR spectra of polysilane 4 and polymer 6 in CDCl 3 were presented in Fig. 2.…”

Section: Characterizationmentioning

confidence: 99%

“…The watersoluble or waterborne photoinitiators could be obtained by introducing ionic groups such as quaternary ammonium salts, carboxylic acids, sulfonates [22][23][24][25][26], or hydrophilic groups such as ethoxyethers and carbohydrates into oil-soluble photoiniatiators [27,28], or through inclusion chemistry such as the inclusion complex of 2-hydroxy-2-methyl-1-phenylpropan-1-one and methylated b-cyclodextrin [21]. Conventionally, water-soluble polysilanes such as 1-3 in Chart 1, were prepared by attaching quaternary ammonium salts [29][30][31][32], ethoxyethers [33][34][35] and multihydroxy groups [36] with polysilanes. Some water-soluble polysilanes such as 1 can also be used as a photoinitiator to photoinitiate a series of vinyl monomers in water solution [31].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

A facile method to prepare a polyethylene glycol modified polysilane as a waterborne photoinitiator

Liang

Zhang

Xiong

et al. 2015

Journal of Photochemistry and Photobiology A: Chemistry

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Section: Characterizationmentioning

confidence: 99%

“…1 H NMR (400 MHz, CDCl 3 ,d, ppm): À0.8 to 0.6 (Si-CH 3 ), 6.4-7.4 (Si-C 6 H 5 ). 13 C NMR (100 MHz, 29 Si NMR (100 MHz, CDCl 3 , d, ppm): À41.2 to À36.6 (-(SiPhMe)-).…”

Section: Preparation Of Polysilanementioning

confidence: 99%

Section: Characterizationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A facile method to prepare a polyethylene glycol modified polysilane as a waterborne photoinitiator

Liang

Zhang

Xiong

et al. 2015

Journal of Photochemistry and Photobiology A: Chemistry

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“…Adding surfactants to polymer solutions with formation of polymer/surfactant complex can substantially alter the physical properties of the starting polymers. The effects can be summarized into the following four categories: (i) Conformational transition of polymers such as coil/globule transition 135,136 and coil/rod transition, 137,138 (ii) Expansion and shift of the phase separation region on the polymer/solvent phase plane, 139 (iii) Formation of composite microphases, 140 (iv) Shift of the sol/gel transition line [141][142][143] and modification of the rheological properties. 71,80,82 When polymers carry small fractions of hydrophobic groups, effects are dramatically enhanced, because the ability of surfactant binding is enhanced by the hydrophobic interaction between polymer hydrophobes and surfactant hydrophobes.…”

Section: Polymer-surfactant Interactionmentioning

confidence: 99%

Theoretical Study of Molecular Association and Thermoreversible Gelation in Polymers

Tanaka

2002

Polym J

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ABSTRACT:This paper reviews our recent theoretical studies of molecular association and thermoreversible gelation in polymer solutions and blends. We first classify fundamental types of association, and propose their static and dynamic characterization. We then develope general theory of associating polymers to study phase transitions induced by molecular association. These transitions include macro-and microphase separation, micellization, hydration, thermoreversible gelation and liquid-crystalization. As for the origin of associative forces, we focus on hydrogen bonding and hydrophobic aggregation. Detailed study on thermoreversible gelation with multiple cross-link junctions is presented. Paying special attention to the multiplicity and sequence length of the network junctions, we derive phase diagrams with coexisting gelation and phase separation, and compare them with experimental data. Local and global structures of the gel networks are studied from molecular point of view. The theory is applied to more complex thermoreversible gels such as binary networks (interpenetrating networks, alternating networks and randomely mixed networks), hydrated networks with high-temperature gelation, gelation strongly coupled to polymer conformational transitions such as coil-to-helix transition. To study dynamics of thermoreversible gels, a simple transient network model is introduced, and creation and annihilation of junctions in the networks are theoretically described. Stationary non-linear viscosity and the dynamic mechanical moduli are calculated as functions of the shear rate, frequency and the chain disengagement rate. From the peak of the loss modulus, the lifetime τ × of the junction is estimated, and from the high frequency plateau of the storage modulus, the number of elastically effective chains in the network is found. Transient phenomena such as stress relaxation and stress overshoot are also theoretically studied. Results are compared with the recent experimental reports on the rheological study of hydrophobically modified water-soluble polymers.KEY WORDS Associating Polymers / Thermoreversible Gelation / Junction Multiplicity / Multicriticality / Transient Networks / Shear Thickening / Elastically Effective Chains / This paper reviews our recent theoretical studies of molecular association and thermoreversible gelation in polymer solutions. We introduce new theoretical frameworks to study phase transitions induced by association of polymer chains and dynamics of aggregation/dissociation processes.In most polymer blends or solutions, polymer chains carry active groups interacting with each other via strongly associative forces which are capable of forming temporal bonds. Hence description of the system in terms of van der Waals type contact energy -or χ-parameter in lattice theoretical terminology -is insufficient. These associative interactions include hydrogen bonding, ionic aggregation, electrostatic interaction, micro-crystallite formation, stereocomplex formation, solvent-complex formation, etc. Since ...

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Unprecedented thermo‐ and ion‐responsive behavior of a non‐ionic water‐soluble polysilane

1997

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Communications negative ion mode. methane): ' H NMR (300 MHz, CDC13): 6 = 4.38 (s, ZH), 7.18-7.95 (m, 28H): I3C NMR (250 MHz, CDCI,): 6 = : Elemental analysis calc. for C46H3"OZ (614.49): C 89.90, H 4.88; found: C 90.02, H 4.76.Thermogravimefric (TG) and Differential Scanning Calorimetric (DSC) Studies: Simultaneous TG-DSC measurements were performed using a TG-DSC 111 (SETARAM, France). The inclusion reaction of acetone from the gas phase was studied in isothermal mode at 25 "C. Inclusion was initiated by saturating the purge gas stream (argon) with acetone at 2 3°C using a temperature controlled saturator filled with liquid acetone. The relatively high concentration of acetone ensured complete and fast enclathration. For the investigation of the thermal degradation of the clathrates, the scanning mode with a linear heating rate of 5 Kimin was applied. Open aluminum crucibles and sample weights of approximately 3 mg were used for all experiments. Due to the symmetric design of both the microbalance and the calorimeter, blank effects were small and easy to correct.Single Crystal X-Ray Diffraction Analyses: Crystals of the inclusion compound suitable for X-ray analysis were obtained by slow evaporation from a solution of 1 in acetone.Data were collected on an ENRAF-NONIUS CAD 4 diffractometer with graphite-monochromatized Cu Ka-radiation at reduced temperature (155 K). Lattice constants and the orientation matrix were refined by least squares fit of 25 reflections in the 0-range 16.66-25.78". Intensities were obtained by the program HELENA [lS]. The standard reflections for intensity control were measured every 60 min and reflections for orientation control every 300th reflection, showing no decay of the crystal during data collection. An initial structure model was initiated by direct methods (SHELXS-86). All independent reflections with non-zero intensities were used to refine the final model to convergence by full matrix least squares (SHELXL-93). Isotropic temperature parameters were applied to the ordered non-hydrogen atoms. The hydrogen atoms were calculated from geometrical considerations and were refined as constrained to bonding carbon and oxygen atoms.Crystal data for 1 . acetone (1:3) monoclinic, P2,/c, a = 11.546 (3), h = 11.789(3), c = 31.598(3) A, p = 97.86(3)", Z = 4, D , = 1.230 gcm", p(CuKn) = 6.1 em-': 8751 independent reflections measured, 5464 observed reflections with I t 2u refined to R = 0.0637, BR = 0.1612. Further details of the crystal structure can be obtained from the Cambridge Crystallographic Data Centre. 12 Union Road, Cambridge CB2 1EZ (UK), on quoting the full journal citation.X-Ray Powder Diffracfion Analyses: Experiments were carried out by means of a horizontal goniometer HZG-4 (Prazisionsmechanik Freiberg, Germany) using C u K a radiation. A special closed sample chamber with a thin polyethylene window guaranteed stability of the clathrate during measurement by maintaining an acetone atmosphere above the sample.

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Spectroscopic Observations of Surfactant-Induced Conformational Changes of a Water-Soluble Polysilane

Cited by 21 publications

References 18 publications

A facile method to prepare a polyethylene glycol modified polysilane as a waterborne photoinitiator

A facile method to prepare a polyethylene glycol modified polysilane as a waterborne photoinitiator

Theoretical Study of Molecular Association and Thermoreversible Gelation in Polymers

Unprecedented thermo‐ and ion‐responsive behavior of a non‐ionic water‐soluble polysilane

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