Aggregation behavior of X-shaped branched block copolymers at the air/water interface: effect of block sequence and temperature

Chen, Yijian; Li, Teng; Xu, Guiying; Zhang, Juan; Zhai, Xueru; Yuan, Jing; Tan, Yang

doi:10.1007/s00396-014-3392-8

Cited by 27 publications

(25 citation statements)

References 47 publications

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“…In accordance with the above results and research from Zhai and Chen [20,39], the salting-in effect and salting-out effect are illustrated in Fig. 5.…”

Section: Effect Of Inorganic Salts On Surface Activitysupporting

confidence: 86%

“…The smaller the value of DH Ã m is, the more stable the micelle is. Sugihara and Hisatomi [63] attributed the intercept to the [19,39,54,60]. These values are larger than those reported for structurally similar linear Tetronics polyether (280-298 K) and branched Tetronics polyether (307.9 and 309.3 K).…”

Section: Enthalpy-entropy Compensationmentioning

confidence: 74%

“…The surface tension initially decreases sharply before point A and thereafter decreases at a slower rate. This transition has been noted for PPO-PEO polyethers [38][39][40]. Before point A, the decrease in surface tension indicates the formation of polyether monolayer absorbed at the air-water interface, while point B corresponds to the formation of multimolecular micelles at the critical micelle concentration (cmc) [40].…”

Section: Cloud Pointmentioning

confidence: 77%

“…8. With the increase in temperature, the hydrophobicity of the PPO chains increases leading to formation of a more compact hydrophobic core and polyether molecules form micelles more easily [39,45]. However the PEO chains expand continuously as the temperature increases; as a result the micellar size increases at higher temperature as confirmed by small angle neutron scattering [33].…”

Section: Effect Of Temperature On Surface Activitymentioning

confidence: 89%

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Synthesis and Properties of a Novel Branched Polyether Surfactant

Shi

Zhao

et al. 2016

J Surfact & Detergents

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A novel branched polyether surfactant (TPE) was prepared by anion polymerization with different proportions of propylene oxide (PO) and ethylene oxide (EO) using 1,1,2,2‐tetrakis(4‐hydroxyphenyl)ethane as a core. The structures and average molecular weight (Mn) of the TPE were characterized by 1H NMR and GPC. The cloud point was determined by turbidimetry in the presence of inorganic salts. Inorganic salts decreased the cloud point of TPE polyether in the following order: Na2CO3 > Na2SO4 > NaCl > CaCl2 > MgCl2. The effects of inorganic salts (NaCl, MgCl2, CaCl2, and NaSCN) and temperature on the surface activity of TPE in aqueous solution were investigated by surface tension measurements. The surface activity parameters and the thermodynamic parameters were calculated from surface tension data. Similar to the effect of increasing temperature, the salting‐out inorganic salts such as NaCl, MgCl2, and CaCl2 favor the micellization and increase the maximum surface excess concentration, while the salting‐in NaSCN has the opposite effect. The influence of NaCl on the morphology of micelles was investigated by TEM. The micellization is entropy‐driven at low temperature and enthalpy‐driven at higher temperature. The TPE polyether has large surface activity and can be used as a demulsifier to break up crude oil emulsions.

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“…In accordance with the above results and research from Zhai and Chen [20,39], the salting-in effect and salting-out effect are illustrated in Fig. 5.…”

Section: Effect Of Inorganic Salts On Surface Activitysupporting

confidence: 86%

Section: Enthalpy-entropy Compensationmentioning

confidence: 74%

Section: Cloud Pointmentioning

confidence: 77%

Section: Effect Of Temperature On Surface Activitymentioning

confidence: 89%

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Synthesis and Properties of a Novel Branched Polyether Surfactant

Shi

Zhao

et al. 2016

J Surfact & Detergents

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“…Li Destri et al [30] further reported the viscoelastic behavior of three PS-b-PMMA copolymers with different block length ratio, proving that the viscoelastic behavior is changing from a predominantly elastic to a viscoelastic one before and after conformation transition. Chen et al [35] found that the aggregation behavior of X-shaped block copolymers at air/water interface can be changed by the variation of the block sequence or temperature. Fluorinated copolymers, especially the fluorinated acrylate copolymers, are excellent choice for design weakly amphiphilic diblock copolymers due to hydrophobicity and high surface activity at air/water interface [8,[36][37][38][39][40][41].…”

Section: Introductionmentioning

confidence: 99%

Tadpole-Shaped POSS-Based Copolymers and the Aggregation Behavior at Air/Water Interface

Zhu

Chen

et al. 2018

Advances in Condensed Matter Physics

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The aggregation behavior of three tadpole-shaped Polyhedral oligomeric silsesquioxane (POSS) based block copolymers using different blocks poly(methyl methacrylate) (PMMA) and poly(trifluoroethyl methacrylate) (PTFEMA) with different block sequence and ratio (POSS-PTFEMA 161 -b-PMMA 236 , POSS-PMMA 277 -b-PTFEMA 130 , and POSS-PMMA 466 -b-PTFEMA 172 ) was investigated on the air-water interface. The interfacial rheology of three block copolymers was studied by surface pressure isotherm, compression modulus measurements, and compression and expansion hysteresis analysis on the Langmuir trough. The block sequence and ratio play a great role in self-assembly behavior at the interface. Based on surface pressure isotherm analysis, a thin film with low elasticity was achieved for the POSS-PTFEMA 161 -b-PMMA 236 . Moreover, for the block copolymer with same segment sequence (POSS-PMMA 2 -b-PTFEMA), the thin film compression capability is increased with increasing the PMMA ratio. The morphology of the deposited LB thin film was illustrated by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). We observed that a thin film was composed by crater-shaped quasi-2D micelles for POSS-PTFEMA-b-PMMA, while it was proved that only flaky texture was observed for both POSS-PMMA 277 -b-PTFEMA 130 and POSS-PMMA 466 -b-PTFEMA 172 . The thickness and area of flaky aggregates were greatly related to PMMA ratio. The different interface self-assembly structure evolution was proposed based on the interfacial rheology and thin film morphology studies.

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