PNIPAmx–PPO36–PNIPAmx thermo-sensitive triblock copolymers: chain conformation and adsorption behavior on a hydrophobic gold surface

Li, Jianyuan; Zhang, Zhijun; Zhou, Xianjing; Chen, Tongquan; Nie, Jun; Du, Binyang

doi:10.1039/c5cp06079f

Cited by 14 publications

(15 citation statements)

References 52 publications

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“…[18][19][20] In principle, this type of technique can detect the adsorption, conformation and interactions of macromolecules at an interface. [21][22][23] For instance, Du and colleagues 24,25 investigated the adsorption of block copolymers on a gold (Au) surface using a QCM technique. The results indicated that the adsorption mechanism of a PNIPAm x -P123-PNIPAm x pentablock terpolymer was mainly determined by the interactions between the pentablock terpolymers molecules with different chain conformations in dilute aqueous solutions at various temperatures and the Au substrates with surface wetting and chemical properties.…”

Section: Introductionmentioning

confidence: 99%

Nanoscale monolayer adsorption of polyelectrolytes at the solid/liquid interface observed by quartz crystal microbalance

Guo

Wang

Yang

et al. 2017

Polym J

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As a device with excellent potential, the quartz crystal microbalance (QCM) has been developed to study the interfacial properties of liquids, such as adsorption/desorption kinetics, electrochemical reaction mechanisms and interfacial viscosity. In this research, the adsorption properties of cationic polyelectrolytes (poly(diallyl dimethylammonium chloride) and poly(allylamine hydrochloride)) on solid surfaces were observed using QCM. The results indicated that the response to adsorption was different with a change in polyelectrolyte solution concentration and that the frequency shift increased as the solution concentration increased. The adsorption of the polyelectrolyte also depends on the solid surfaces and solution pH values. Furthermore, the change in the molecular conformation of the polyelectrolyte molecules is the main factor that affects the adsorption properties and structures.

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Section: Introductionmentioning

confidence: 99%

Nanoscale monolayer adsorption of polyelectrolytes at the solid/liquid interface observed by quartz crystal microbalance

Guo

Wang

Yang

et al. 2017

Polym J

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“…2-Bromoisobutyrylbromide (BIBB, Sigma-Aldrich, 98%) was used as received. PPO- b -PNIPAm was synthesized according to the literature . Briefly, the macroinitiator was synthesized by the esterification of PPO-OH with BIBB.…”

Section: Methodsmentioning

confidence: 99%

“…PPO-b-PNIPAm was synthesized according to the literature. 41 Briefly, the macroinitiator was synthesized by the esterification of PPO-OH with BIBB. Through a standard ATRP procedure, the diblock copolymers with different degrees of polymerization of PNIPAm were synthesized.…”

Section: ■ Experimental Partmentioning

confidence: 99%

“…The phase transition of a polymer at LCST causes corresponding change in heat capacity, which can be detected by DSC. 41 Figure 5 shows the heat capacity change with temperature, which shows that the LCST values of PPO, PNIPAm, P1, and P2 are 8.8, 33.4, 34.1, and 33.7 °C, respectively. The incorporation of a hydrophilic segment increases the LCST, while copolymerization with hydrophobic monomers lowers the LCST.…”

Section: ■ Experimental Partmentioning

confidence: 99%

“…22 Li et al studied the LCST of PNIPAm-b-PPO-b-PNIPAm and found that the LCST was dependent on the polymer structure. 41 With the increase in the block length of PNIPAm, the influence of PPO on the LCST of the copolymer became weak and for the triblock copolymer with the longest PNIPAm block, only one LCST was observed. Because of the relatively longer PNIPAm block, P1 and P2 show one LCST, which is similar to that of the PNIPAm.…”

Section: ■ Experimental Partmentioning

confidence: 99%

See 2 more Smart Citations

Surface Activity and Structure of Temperature-Responsive Polymer Surfactants Based on PNIPAm at the Air/Solution Interface

et al. 2021

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Thermally sensitive polymers have attracted tremendous interest in the design of stimulus-responsive surfactants. In this article, poly(propylene oxide)-bpoly(N-isopropylacrylamide) (PPO-b-PNIPAm) with different block lengths of PNIPAm was synthesized through atom transfer radical polymerization (ATRP). Different from commercial Pluronic surfactants, four distinct sections appeared in the decrease of surface tension with concentration. First, with increasing concentration, the amount of adsorbed polymers increased and the surface tension decreased sharply until a plateau was reached, which was caused by the rearrangement of methyl groups. The increasing adsorbed amount of PPO-b-PNIPAm resulted in the rearrangement of isopropyl groups, which changed from a lying down or horizontal conformation to a standing up or vertical conformation. This behavior led to the decrease in surface tension in part III until the critical micelle concentration (CMC) was reached. The surface tension of PPO-b-PNIPAm was thermally responsive. Except for the hysteresis observed in the first cycle, the surface tension was reversible during the heating-andcooling cycles. At low concentrations, the low surface tension at higher temperatures was mainly caused by the increasing adsorption amount and ordered arrangement of methyl groups, while the standing up conformation of isopropyl groups at higher concentrations resulted in the low surface tension observed at high temperatures.

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Diselenide‐bearing crosslinked micelles‐reduced and stabilized gold nanoparticles in‐situ

Lin

Yan

Pan

et al. 2021

J of Applied Polymer Sci

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Gold nanoparticles (GNPs), usually fabricated through reduction and stabilization two steps, have been widely used in biomedical field. Here, the six-armed star copolymer was synthesized and self-assembled into crosslinked micelles for the in-situ preparation of GNPs in one-step without external reductant.The copolymer and their precursors were synthesized by a combination of ring-opening polymerization (ROP), activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP), and Michael addition reaction. Their molecular weights and structures were measured by gel permeation chromatography (GPC) and 1 H NMR. The diselenide bond of crosslinked micelles reduced AuCl 4 À to GNPs, and the crosslinked micelles stabilized the GNPs in-situ. Through increasing AuCl 4 À concentration, the collision probability between the GNPs increased, with particle diameters of 1.5, 2.3, and 3.0 nm. Moreover, the GNPs showed good stability, and the wavelength of maximum absorbance (λ max ) did not change under different dilution, temperature, and storage conditions. Furthermore, integrating dissipative particle dynamics (DPD) simulations and scripts with experiments, the formation process of crosslinked micelles, the stabilization process, and the size regulation of GNPs at mesoscopic scale were revealed. Therefore, this stable crosslinked micelles/GNPs hybrid material is expected to be used as a nanocarrier in an integrated diagnosis and treatment system.

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PNIPAm_x–PPO₃₆–PNIPAm_x thermo-sensitive triblock copolymers: chain conformation and adsorption behavior on a hydrophobic gold surface

Cited by 14 publications

References 52 publications

Nanoscale monolayer adsorption of polyelectrolytes at the solid/liquid interface observed by quartz crystal microbalance

Nanoscale monolayer adsorption of polyelectrolytes at the solid/liquid interface observed by quartz crystal microbalance

Surface Activity and Structure of Temperature-Responsive Polymer Surfactants Based on PNIPAm at the Air/Solution Interface

Diselenide‐bearing crosslinked micelles‐reduced and stabilized gold nanoparticles in‐situ

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