Phase structures and morphologies determined by self-organization, vitrification, and crystallization: confined crystallization in an ordered lamellar phase of PEO-b-PS diblock copolymer

Zhu, Lei; Cheng, Stephen Z. D.; Calhoun, Bret H.; Ge, Qing; Quirk, Roderic P.; Thomas, Edwin L.; Hsiao, Benjamin S.; Yeh, Fengji; Lotz, Bernard

doi:10.1016/s0032-3861(00)00902-2

Cited by 277 publications

(365 citation statements)

References 54 publications

Supporting

Mentioning

351

Contrasting

Unclassified

Order By: Relevance

“…Xu et al [59] measured the interaction between PS and PEO and reported χ PS,PEO = 0.02 ∼ 0.03. Zhu et al [60] also measured χ PS,PEO and and obtained χ PS,PEO = −0.00705 + 21.3/T . The polymerization index of PS-PEO diblock copolymer used in the experiments [51] is typically ≃ 1000, thus we expect that χ PS,PEO N is sufficiently larger than the critical value χ c N = 10.495 [14].…”

Section: Comparison With Experimentsmentioning

confidence: 99%

Density functional simulation of spontaneous formation of vesicle in block copolymer solutions

Uneyama

2007

The Journal of Chemical Physics

112

View full text Add to dashboard Cite

We carry out numerical simulations of vesicle formation based on the density functional theory for block copolymer solutions. It is shown by solving the time evolution equations for concentrations that a polymer vesicle is spontaneously formed from the homogeneous state. The vesicle formation mechanism obtained by our simulation agree with the results of other simulations based on the particle models as well as experiments. By changing parameters such as the volume fraction of polymers or the Flory-Huggins interaction parameter between the hydrophobic subchains and solvents, we can obtain the spherical micelles, cylindrical micelles or bilayer structures, too. We also show that the morphological transition dynamics of the micellar structures can be reproduced by controlling the Flory-Huggins interaction parameter.

show abstract

Section: Comparison With Experimentsmentioning

confidence: 99%

Density functional simulation of spontaneous formation of vesicle in block copolymer solutions

Uneyama

2007

The Journal of Chemical Physics

112

View full text Add to dashboard Cite

show abstract

“…Amongst the most convenient common methods to achieve confinement at the nanoscale are crystalline-amorphous diblock copolymers 13 (with one crystallizable block), due to their selfassembled microdomains. Diblock copolymers generate various microphase separation structures 14 , such as spheres, cylinders, gyroids and lamellae.…”

Section: Introductionmentioning

confidence: 99%

Orientation Control and Crystallization in a Soft Confined Phase Separated Block Copolymer

Alharbe

Hobbs

2017

Macromolecules

View full text Add to dashboard Cite

Phone: +44 (0)114 22 24532Fax: +44 (0)114 22 23555 ABSTRACTMicrodomain orientation and crystallization were examined in a crystalline-amorphous diblock copolymer, hydrogenated poly (high-1,4-butadiene)-b-poly(high-3,4-isoprene) (E/MB), which forms cylinders of the crystallizable block (polyethylene, E). Atomic force microscopy (AFM) was used to locally control the orientation of the E cylinders. The orientation process and subsequent crystallization behavior were investigated in situ as a function of temperature by AFM. Fully confined crystallization was observed within the range of 25-50 °C, with templated and breakout crystallization observed at higher crystallization temperature. The growth rate of templated crystallization along and perpendicular to the existing microdomain structure was measured and the ratio between these rates found to increase rapidly with decreasing temperature with a change from ~4.8 at 100 °C to ~8 at 97 °C. Two maxima in the degree of orientation of the crystallized regions were found, one at relatively small supercoolings (e.g. 95 °C) where the differential in growth rate along and across microdomain boundaries is high, and one at high supercoolings (25-50 °C) where crystallization is completely dominated by nucleation.

show abstract

“…For the model parameters, the Kuhn lengths, b PEO ¼ 0:56 ½nm and b PS ¼ 0:68 ½nm, v 0 ¼ À0:007 05 þ 21:3=T [20], v A ¼ 0:069 ½nm 3 , and v B ¼ 0:179 ½nm 3 are used. In contrast to the case of polymer blends, where we only need to consider homogeneous states, here we must deal with spatial inhomogeneity associated with microphase separation, which leads to two effects not present in the case of the homogeneous system.…”

mentioning

confidence: 99%

Thermodynamics of Ion-Containing Polymer Blends and Block Copolymers

2011

View full text Add to dashboard Cite

We develop a theory for the thermodynamics of ion-containing polymer blends and diblock copolymers, taking polyethylene oxide (PEO), polystyrene and lithium salts as an example. We account for the tight binding of Li þ ions to the PEO, the preferential solvation energy of anions in the PEO domain, the translational entropy of anions, and the ion-pair equilibrium between EO-complexed Li þ and anion. Our theory is able to predict many features observed in experiments, particularly the systematic dependence in the effective parameter on the size of the anions. Furthermore, comparison with the observed linear dependence in the effective on salt concentration yields an upper limit for the binding constant of the ion pair. DOI: 10.1103/PhysRevLett.107.198301 PACS numbers: 83.80.Uv, 77.22.Àd, 82.35.Rs, 83.80.Sg There is much current interest in ion-containing polymers as materials for energy applications [1]. Of particular interest for rechargeable battery applications are block copolymers [2][3][4] of an ion-dissolving block, typically polyethylene oxide (PEO), and a nonconducting block such as polystyrene (PS), doped with lithium salts. The lithium ions are complexed with EO groups [5], and together with their counterions, provide the charge carriers [6]. The nonconducting block can be tuned to confer other functions, such as mechanical robustness [3,4,6].Experimentally, the addition of lithium salts has been shown to have significant effects on the order-order and order-disorder transitions in block copolymers [3,7,8]. Among other effects, it is found that the effective parameter characterizing the immiscibility of the two blocks increases linearly with salt concentration [9,10],where is the intrinsic Flory-Huggins parameter for the salt-free system, r is the molar ratio of Li þ ions to EO monomers, and the slope m depends on the anion type. Wanakule et al. [10] found that m decreases with increasing anion radius a. No existing theory describes this behavior. Since the Li þ ions are strongly bound to the EO groups [11], one may consider the PEO with its bound Li þ ions as an effective polyelectrolyte, with the anions acting as the counterions. However, existing theories for diblock copolymers with a charged block and a neutral block [12,13] predict enhanced miscibility between the blocks relative to the uncharged system, opposite to experimental observations; there is also no dependence on the radius of the counterions.The strong binding of Li þ to the EO groups clearly will affect the thermodynamics of PEO-PS diblock copolymers. However, as suggested in Ref.[10] and demonstrated here, a key effect in these ion-containing polymers is the solvation energy of the anions, which has been ignored in all existing theories of ion-containing polymers. An earlier theory developed by one of us [14], taking into account the effects of ion solvation, predicted that adding salts to binary polymer blends can decrease the miscibility between the two polymers. However, that theory assumed the salt ions to be fully dissociated a...

show abstract

Phase structures and morphologies determined by self-organization, vitrification, and crystallization: confined crystallization in an ordered lamellar phase of PEO-b-PS diblock copolymer

Cited by 277 publications

References 54 publications

Density functional simulation of spontaneous formation of vesicle in block copolymer solutions

Density functional simulation of spontaneous formation of vesicle in block copolymer solutions

Orientation Control and Crystallization in a Soft Confined Phase Separated Block Copolymer

Thermodynamics of Ion-Containing Polymer Blends and Block Copolymers

Contact Info

Product

Resources

About