Poly(ethylene oxide)-<i>b</i>-poly(<scp>l</scp>-lactide) Diblock Copolymer/Carbon Nanotube-Based Nanocomposites: LiCl as Supramolecular Structure-Directing Agent

Meyer, Franck; Raquez, Jean-Marie; Verge, Pierre; Arenaza, Inger Martínez de; Coto, Borja; Voort, Pascal Van Der; Meaurio, Emilio; Dervaux, Bart; Sarasua, Jose‐Ramon; Prez, Filip Du; Dubois, Philippe

doi:10.1021/bm201149g

Cited by 29 publications

(27 citation statements)

References 30 publications

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“…51 In simple terms there is an enhancement of the χ eff with the formation of lithium-PEO complexes. 39 The strong binding will clearly affect the thermodynamics, solvation energy of the anions and miscibility of the system. 39 The strong binding will clearly affect the thermodynamics, solvation energy of the anions and miscibility of the system.…”

Section: Surface Morphology On Different Substratementioning

confidence: 99%

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A vertical lamellae arrangement of sub-16 nm pitch (domain spacing) in a microphase separated PS-b-PEO thin film by salt addition

et al. 2015

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Ultra-small feature size (~8 nm domain width) nanopatterns have been achieved using a symmetric polystyrene-b-polyethylene oxide (PS-b-PEO) block copolymer (BCP) of low molecular weight (PS and PEO blocks of 5.5 and 5.3 kg mol -1 respectively). The work represents the smallest feature size attained and the first observation of a well-controlled film of a perpendicularly oriented lamellar pattern in thin film form for this system. The polymer synthesized and described herein has a value χN (= 7.7), below the expected BCP phase segregation limit of 10.5. These patterns were achieved by amplification of the effective interaction parameter (χ eff ) of the BCP system by the addition of lithium chloride (LiCl) salt. A model where the Li + ions strongly coordinate with the PEO block without affecting the PS chain is proposed to explain the ordered self-assembly. The morphological and structural evolution for these PS-b-PEO/LiCl thin films was investigated by variation of the experimental parameters such as temperature, annealing time, salt concentrations, solution aging time, annealing solvent etc. All the experimental parameters have significant effects on the morphology, domain spacing, defectivity or surface roughness of these symmetric BCP thin films as evident from different microscopic and spectroscopic techniques. Possible hard mask applications in the area of lithography are demonstrated. Substrates were cleaned by ultrasonication in acetone (30 min) and toluene (30 min) and dried under nitrogen. A 1 wt% PS-b-PEO solution in toluene (5 gm) was stirred for 12 h at room temperature. LiCl was dissolved in ethanol and in THF separately to make 2.5 mg/mL solution. Then the necessary amount of LiCl/ethanol or LiCl/THF solution (varying from 0.025 ml to 2 ml) was added to the prepared PS-b-PEO/toluene solution with a micropipette. Scheme 2 (a) SEC chromatograph of the final diblock PS-b-PEO (b) 1 H-NMR spectra of sample PS-b-PEO indicating the chemical shifts of the four protons for PEO at ~4-4.5 ppm (green) and of the five aromatic protons for PS at ~6.8-7.5 ppm (red). (a) (b) Fig. 1 (a, c) Tapping mode AFM images and (b, d) SEM images of the surface morphology of the PS-b-PEO thin film following solvent annealing in toluene at 60 o C for 30 min with the addition of 0.05 ml of (a, b) LiCl-ethanol and (c, d) LiCl-THF respectively.Fig 4 AFM images of the film annealed in toluene for 30 min at a temperature (a) 40 o C (b) 50 o C. (c, e, g) AFM and (d, f, h) SEM images of the film annealed in toluene at a temperature 60 o C for 15 min, 45 min and 1h respectively.Fig 5 Surface morphology and topography of the films with LiCl-THF solution stirred for 30 min for the salt concentration of (a) 1 ml., (b, c) 1.25 ml., and (d) 1.5 ml. The variation in morphology of the films with 1 ml. of LiCl-THF solution for the stirring time of (e) 45 min, (f) 1h, (g, inset) 2h and (h) 3h.

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Section: Surface Morphology On Different Substratementioning

confidence: 99%

“…Based on the previous studies 34,[38][39] it was hoped to achieve microphase separated ordered perpendicularly oriented lamellae for the symmetric PS-b-PEO system. Based on the previous studies 34,[38][39] it was hoped to achieve microphase separated ordered perpendicularly oriented lamellae for the symmetric PS-b-PEO system.…”

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confidence: 99%

A vertical lamellae arrangement of sub-16 nm pitch (domain spacing) in a microphase separated PS-b-PEO thin film by salt addition

et al. 2015

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“…For the LiAsF 6 /U-PEG system (Figure 6a), the intensity of each peak did not change significantly upon increasing the lithium salt content, until the Li-to-U-PEG ratio reached 1:8. In general, the highest conductivity and T g behavior occurs in most cases at a Li-to-PEG ratio of 1:8, indicating that the lithium salt interacts almost entirely with the ether groups at molar ratios lower than 1:8 [17][18][19]36]. In this study, we found, however, that the highest T g behavior occurred at a Li-to-PEG ratio of 1:4, presumably because the U and acrylate groups in the U-PEG system also had inter-association ability at relatively high lithium salt contents.…”

Section: −1mentioning

confidence: 94%

Supramolecular Functionalities Influence the Thermal Properties, Interactions and Conductivity Behavior of Poly(ethylene glycol)/LiAsF6 Blends

et al. 2013

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Abstract:In this study, we tethered terminal uracil groups onto short-chain poly(ethylene glycol) (PEG) to form the polymers, uracil (U)-PEG and U-PEG-U. Through AC impedance measurements, we found that the conductivities of these polymers increased upon increasing the content of the lithium salt, LiAsF 6 , until the Li-to-PEG ratio reached 1:4, with the conductivities of the LiAsF 6 /U-PEG blends being greater than those of the LiAsF 6 /U-PEG-U blends. The ionic conductivity of the LiAsF 6 /U-PEG system reached as high as 7.81 × 10 −4 S/cm at 30 °C. Differential scanning calorimetry, wide-angle X-ray scattering, 7 Li nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy revealed that the presence of the uracil groups in the solid state electrolytes had a critical role in tuning the glass transition temperatures and facilitating the transfer of Li + ions.

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“…Moreover, the surface modification of CNTs through covalent-noncovalent functionalization with supramolecular molecules is crucial for developing high performance materials based on CNTs and supramolecular materials. 34 Cyclodextrins are cyclic host molecules, which are composed of glucose units and connected through -1,4glycosidic linkages. 35 Cyclodextrins have a characteristic torus truncated-cone shape structure with a hydrophilic exterior and a hydrophobic cylindrical interior.…”

Section: Introductionmentioning

confidence: 99%

Surface Immobilization of Carbon Nanotubes by <I>β</I>-Cyclodextrins and Their Inclusion Ability

Bhoi¹,

Imae²,

Ujihara³

et al. 2013

j. nanosci. nanotech.

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The surface immobilization of beta-cyclodextrins on the surface of multiwalled carbon nanotubes (MWNTs) in an aqueous medium was achieved by covalent-binding of diamino-functionalized beta-cyclodextrin with carboxylic acid-functionalized MWNTs via amide linkages using a water-soluble condensation agent at room temperature. The obtained product denoted as beta-cyclodextrin-modified MWNTs was highly dispersible in an aqueous medium. The covalent surface functionalization of MWNTs by beta-cyclodextrin was characterized by FTIR, TGA, EDS and TEM. The thermogravimetric analyses indicated that -70 wt% beta-cyclodextrin was attached on the surface of MWNTs. Furthermore, the fluorometric analysis for adsorption of rhodamine 6G dye suggested that the formation of beta-cyclodextrin-dye inclusion conjugate takes place prior to the adsorption of dyes on MWNTs and uniform dispersion of MWNTs after surface immobilization allows superior fluorescence quenching than the pristine and oxidized MWNTs.

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Poly(ethylene oxide)-b-poly(l-lactide) Diblock Copolymer/Carbon Nanotube-Based Nanocomposites: LiCl as Supramolecular Structure-Directing Agent

Cited by 29 publications

References 30 publications

A vertical lamellae arrangement of sub-16 nm pitch (domain spacing) in a microphase separated PS-b-PEO thin film by salt addition

A vertical lamellae arrangement of sub-16 nm pitch (domain spacing) in a microphase separated PS-b-PEO thin film by salt addition

Supramolecular Functionalities Influence the Thermal Properties, Interactions and Conductivity Behavior of Poly(ethylene glycol)/LiAsF6 Blends

Surface Immobilization of Carbon Nanotubes by <I>β</I>-Cyclodextrins and Their Inclusion Ability

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