Experimental and Computational Study of the Effect of Alcohols on the Solution and Adsorption Properties of a Nonionic Symmetric Triblock Copolymer

Liu, Xiaomeng; He, Feng; Salas, Carlos; Pasquinelli, Melissa A.; Genzer, Jan; Rojas, Orlando J.

doi:10.1021/jp207190c

Cited by 9 publications

(3 citation statements)

References 47 publications

(88 reference statements)

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“…One simple and effective way for altering the surface chemistry of cellulose is through adsorption of functional surfactants and polymers. We have investigated the adsorption on cellulose of nonionic block copolymers − as well as triblock copolymers end-capped with cationic chains . Likewise, the attachment on hydrophilic surfaces of copolymers containing cationic poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) with hydrophobic segments has been reported, and the adsorption mechanism has been attributed to electrostatic interactions between the cationic segments and the anionic surface, both for quaternized or nonquaternized PDMAEMA.…”

Section: Introductionmentioning

confidence: 99%

Effect of Molecular Architecture of PDMAEMA–POEGMA Random and Block Copolymers on Their Adsorption on Regenerated and Anionic Nanocelluloses and Evidence of Interfacial Water Expulsion

et al. 2015

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Block copolymers of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) with varying block sizes were synthesized by consecutive reversible addition-fragmentation chain transfer (RAFT) polymerization and then exposed to cellulose substrates with different anionic charge density. The extent and dynamics of quaternized PDMAEMA-b-POEGMA adsorption on regenerated cellulose, cellulose nanofibrils (CNF), and (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)-oxidized cellulose nanofibrils (TOCNF) was determined by using electromechanical and optical techniques, namely, quartz crystal microbalance (QCM-D) and surface plasmon resonance (SPR), respectively. PDMAEMA-b-POEGMA equilibrium adsorption increased with the anionic charge of cellulose, an indication of electrostatic interactions. Such an observation was further confirmed by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Depending on their architecture, adsorption on TOCNF of some of the PDMAEMA-b-POEGMA copolymers produced a significant reduction in QCM frequency, as expected from large mass uptake, while surprisingly, other copolymers induced the opposite effect. This latter, remarkable behavior was ascribed to coupled water expulsion from the interface upon charge neutralization of anionic surface sites with adsorbing cationic polymer segments. These observations were further investigated with SPR and QCM-D measurements using deuterium oxide solvent exchange to determine the amount of coupled water at the TOCNF-block copolymer interface. Finally, random copolymers with similar composition adsorbed to a larger extent compared to the respective block copolymers, revealing the effect of adsorbed loops and tails as well as hydration.

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Section: Introductionmentioning

confidence: 99%

Effect of Molecular Architecture of PDMAEMA–POEGMA Random and Block Copolymers on Their Adsorption on Regenerated and Anionic Nanocelluloses and Evidence of Interfacial Water Expulsion

et al. 2015

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“…where θ is the polymer volume fraction, p is the vapor pressure of the polymer mixture solution, and p 0 is the vapor pressure of the pure solvent [33]. A summary of the derivatives is shown in Table 2.…”

Section: Mesodyn Coarse-grained Calculationmentioning

confidence: 99%

Molecular Dynamics Simulation of Nanocellulose-Stabilized Pickering Emulsions

et al. 2021

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While the economy is rapidly expanding in most emerging countries, issues coupled with a higher population has created foreseeable tension among food, water, and energy. It is crucial for more sustainable valorization of resources, for instance, nanocellulose, to address the core challenges in environmental sustainability. As the complexity of the system evolved, the timescale of project development has increased exponentially. However, research on the design and operation of integrated nanomaterials, along with energy supply, monitoring, and control infrastructure, has seriously lagged. The development cost of new materials can be significantly reduced by utilizing molecular simulation technology in the design of nanostructured materials. To realize its potential, nanocellulose, an amphiphilic biopolymer with the presence of rich -OH and -CH structural groups, was investigated via molecular dynamics simulation to reveal its full potential as Pickering emulsion stabilizer at the molecular level. This work has successfully quantified the Pickering stabilization mechanism profiles by nanocellulose, and the phenomenon could be visualized in three stages, namely the initial homogenous phase, rapid formation of micelles and coalescence, and lastly the thermodynamic equilibrium of the system. It was also observed that the high bead order was always coupled with a high volume of phase separation activities, through a coarse-grained model within 20,000 time steps. The outcome of this work would be helpful to provide an important perspective for the future design and development of nanocellulose-based emulsion products, which cater for food, cosmeceutical, and pharmaceutical industries.

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“…We show here that it brings about a substantial effect despite the strong competition of these specific bonds with other hydrogen bonds in the system. In contrast to some simpler alcohols, the effect of which was studied by high sensitivity differential scanning calorimetry (DSC) (for EO 6 PO 4 EO 6 ) and more recently by various experimental and computational methods (for EO 37 PO 56 EO 37 ), our additives act unambiguously in favor of chain dehydration and self‐aggregation.…”

Section: Introductionmentioning

confidence: 99%

Premicellar interaction of PEO–PPO–PEO triblock copolymers with partially hydrophobic alcohols: NMR study

Křı́ž

Dybal

2013

Magnetic Reson in Chemistry

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The interactions of three alcohols, namely, 2-butanol (BuOH), 3-methyl-2-butanol (MeBuOH), and 3,3-dimethyl-2-butanol (Me2BuOH) with propylene oxide octamer (PO8) and the copolymers (EO)8(PO)13(EO)8(L35) and (EO)13(PO)30(EO)13(L64) in D2O were studied using (13)C NMR spectra and relaxations and (1)H PFG NMR diffusion measurements. For L64, it was shown that the temperature at which the PO chain starts to change its conformation under dehydration decreases by 6 K for each additional methyl group in the alcohol molecule (i.e. with increasing its hydrophobicity), and the analogous conformation states are attained at temperatures approximately 10 K lower compared using ketonic analogs of the alcohols under the same conditions. Also, the first signs of L64 aggregation, according to the normalized diffusion coefficients, are at temperatures 7, 10, and 13 K lower for BuOH, MeBuOH, and Me2BuOH, respectively. These effects are much weaker for (PO)13 in L35 or nonexistent for (PO)8 in PO8, thus showing the role of cooperativity in dehydration and aggregation processes. According to diffusion measurements, the molar fraction of the alcohol hydrogen bonded to L64 increases with its hydrophobicity and, in an apparent conflict with thermodynamics, with increasing temperature at which also higher NOE can be observed. Strong hydrogen bond interaction, which is in cooperation with hydrophobic interaction, does not preclude the exchange between bound and free states of the alcohol, however. Using (13)C transverse relaxation, its correlation time is shown to be of the order of 10 ms.

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Experimental and Computational Study of the Effect of Alcohols on the Solution and Adsorption Properties of a Nonionic Symmetric Triblock Copolymer

Cited by 9 publications

References 47 publications

Effect of Molecular Architecture of PDMAEMA–POEGMA Random and Block Copolymers on Their Adsorption on Regenerated and Anionic Nanocelluloses and Evidence of Interfacial Water Expulsion

Effect of Molecular Architecture of PDMAEMA–POEGMA Random and Block Copolymers on Their Adsorption on Regenerated and Anionic Nanocelluloses and Evidence of Interfacial Water Expulsion

Molecular Dynamics Simulation of Nanocellulose-Stabilized Pickering Emulsions

Premicellar interaction of PEO–PPO–PEO triblock copolymers with partially hydrophobic alcohols: NMR study

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