Isothermal Crystallization Kinetics of Poly(ethylene oxide)/Poly(ethylene glycol)-g-silica Nanocomposites

Wen, Xiangning; Su, Yunlan; Li, Shaofan; Ju, Weilong; Wang, Dujin

doi:10.3390/polym13040648

Cited by 11 publications

(5 citation statements)

References 60 publications

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“…This observation is in contrast to what has been observed by Hor et al, who have shown that the viscosity increase upon the addition of NPs has no temperature or MW dependence . A final observation that is consistent with Wen et al is the decrease in K g G as MW is increased (see Supporting Information), indicating that lower MW PEO (in the MW range explored here) has a higher energy barrier for secondary nucleation …”

supporting

confidence: 86%

Organizing Nanoparticles in Semicrystalline Polymers by Modifying Particle Diffusivity

et al. 2022

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We have previously shown that semicrystalline polymers can be reinforced by adding nanoparticles (NPs) and then ordering them into specific motifs using the crystallization process. A key result we have found is that when the spherulite growth rate is slowed below a critical value, then, NPs can order into the amorphous interlamellar regions of the semicrystalline structure. The effects of spherulite growth rate in this context have previously been examined, and here we focus on the role of NP diffusivity. We achieve this goal by changing the poly(ethylene oxide) (PEO) molecular weight as a route to altering the matrix viscosity. In particular, four molecular weights of PEO were employed ranging from 5.4−46 kDa. Each sample was loaded with 10 vol % of bare 14 nm diameter silica NPs. After initially studying spherulite growth rates, experiments were designed to fix the spherulite growth rate across sample molecular weights to study particle ordering, induced by polymer crystallization. We find that, at the fastest growth rate studied (12 μm/s), the lowest molecular weight sample showed the highest order, presumably due to enhanced particle mobility. However, as the spherulite growth rate is slowed, the maximum ordering behavior is observed at intermediate molecular weights. The trend observed at slow growth rates is explained by the large-scale segregation of NPs (presumably into the grain boundaries, i.e., the interspherulitic regions); evidence for this is the observed transition of spherulite growth to diffusion-control at slow growth rates in the lowest molecular weight PEO sample studied.

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confidence: 86%

Organizing Nanoparticles in Semicrystalline Polymers by Modifying Particle Diffusivity

et al. 2022

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“…For LDPE4k and HDPE67k systems, HDPE1289- g -SiO 2 can increase the T c value of the matrix more than that of unmodified SiO 2 nanoparticles, indicating that PE-grafted-SiO 2 nanoparticles act as more effective nucleating agents. Similar results have already been obtained in the literature. − Although adding PGNPs may increase the viscosity of the matrix, which could hinder diffusion to the growth front, the more significant nucleation effect of PGNPs tends to improve the overall nonisothermal crystallization rate . However, in the LDPE34k system, the crystallization peak obviously widens after the addition of SiO 2 nanoparticles.…”

Section: Resultssupporting

confidence: 84%

Effect of the Miscibility between Grafted and Matrix Chains on the Dispersion and Crystallization of Polyethylene-Grafted Silica Nanocomposites

Li,

Ju,

Liu

et al. 2023

Macromolecules

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The properties of polymer nanocomposites (PNCs) greatly depend on the dispersion of nanoparticles within the polymer matrix. In this work, linear high-density polyethylene grafted with SiO2 nanoparticles (HDPE1289-g-SiO2, where 1289 indicates the weight-average molar mass of the grafted polyethylene) was synthesized via the “grafting to” method and added to PE matrices with three different molecular weights and branching degrees (LDPE4k, LDPE34k, and HDPE67k) by a solution blending method. The dispersion and crystallization behaviors of PE/HDPE1289-g-SiO2 PNCs were studied by transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), and polarized light optical microscopy (PLOM). In a low-density polyethylene (LDPE4k) matrix with a small ratio of matrix-to-grafted chain length (P/N), HDPE1289-g-SiO2 nanoparticles are better dispersed when compared with unmodified SiO2, a result related to the low P/N (entropic effect). With the increase of the molecular weight of the matrix (LDPE34k) with high P/N, both the HDPE1289-g-SiO2 and unmodified SiO2 nanoparticles have a poor dispersion with nanoparticles’ aggregates in the matrix and similar nucleation effects on the matrix. In the above two systems, we used the P/N parameter commonly used for linear systems as an approximation because the 13C NMR results showed that LDPE4k and LDPE34k contain only butyl and longer branches (≥6C). Interestingly, in the high-density polyethylene (HDPE67k) matrix with high P/N, HDPE1289-g-SiO2 nanoparticles are better dispersed than unmodified SiO2 due to the miscibility between the grafted and matrix polyethylene (enthalpic effect). For the HDPE67k matrix, HDPE1289-g-SiO2 nanoparticles exhibit a supernucleation effect on HDPE, with the nucleation efficiency higher than 100% due to their good dispersion. Our results show that for the PE/HDPE1289-g-SiO2 PNCs, the lower the P/N or the more similar the chain structure of the grafted and matrix polymer is, the better the dispersion of HDPE1289-g-SiO2 nanoparticles, thus improving their nucleation ability.

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“…However, a slight inclination of α 1 toward the lower angle direction is noticed upon further NC addition, indicating a small rise in the lattice spacings, theoretically pulling down the crystallinity (Table S2). Nevertheless, the increment in the TiO 2 NCs is apparently boosting the nanocomposite crystallinity with more defined α phases, which can be related to a secondary crystallization process . The prominent peak of TiO 2 at 2θ:25° of the (101) plane in the Nylon-6,6 composite gets intensified along with the NC addition, indicating the aggregation of TiO 2 NCs .…”

Section: Resultsmentioning

confidence: 99%

“…Nevertheless, the increment in the TiO 2 NCs is apparently boosting the nanocomposite crystallinity with more defined α phases, which can be related to a secondary crystallization process. 38 The prominent peak of TiO 2 at 2θ:25°of the (101) plane in the Nylon-6,6 composite gets intensified along with the NC addition, indicating the aggregation of TiO 2 NCs. 39 From the XRD diffractogram of pure anatase TiO 2 given in Figure 1d, the presence of TiO 2 in the Nylon-6,6 electrospun nanocomposite film can be confirmed.…”

Section: Morphological Assay and The Electrical Performance Of The Se...mentioning

confidence: 96%

High-Performance Self-Cleaning Triboelectric Mini Humidity Sensor Enabled by Facet Engineered Titania Nanocrystals Adorned Nylon-6,6 Electrospun Nanofibers

Mathew,

Sunil,

Joseph

et al. 2024

ACS Appl. Eng. Mater.

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Self-powered humidity sensors offer a promising avenue for enhancing environmental monitoring, optimizing resource utilization, and mitigating environmental damage across various sectors. Triboelectric nanogenerators are a well-recognized sustainable energy harvesting technology from ubiquitous mechanical energy that can power small devices, including sensors. Humidity monitoring has become significant in predicting and controlling losses from agricultural to industrial applications. However, the polluted surroundings can stealthily bring down the triboelectric output, corrupting the sensing potential. Hence, this work focuses on constructing a self-cleaning and self-powered mini humidity sensor system with a 1 cm 2 frictional surface by integrating facet-oriented titania nanocrystals (TiO 2 NCs) into hygroscopic Nylon-6,6 via electrospinning. The high specific surface area owing to the fine average fiber diameter of 42 nm and the heterogeneous nanocomposite interfaces creating more charge storage sites induce an immense current density of 130 mA m −2 with a massive power density of 5 W m −2 . The device is well-equipped with RH (relative humidity) warning systems consisting of a visual and buzzer alert, which showcases a remarkable response (0.5 s) and recovery time (1.9 s), along with output stability over 150,000 cycles of continuous contact and separation. In addition, the combination of high and low energy facets in the TiO 2 NCs efficiently drives the photodegradation process by removing contaminants on the frictional layer surface and restoring 97% of the electric output, promising a prolonged and consistent application.

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Isothermal Crystallization Kinetics of Poly(ethylene oxide)/Poly(ethylene glycol)-g-silica Nanocomposites

Cited by 11 publications

References 60 publications

Organizing Nanoparticles in Semicrystalline Polymers by Modifying Particle Diffusivity

Organizing Nanoparticles in Semicrystalline Polymers by Modifying Particle Diffusivity

Effect of the Miscibility between Grafted and Matrix Chains on the Dispersion and Crystallization of Polyethylene-Grafted Silica Nanocomposites

High-Performance Self-Cleaning Triboelectric Mini Humidity Sensor Enabled by Facet Engineered Titania Nanocrystals Adorned Nylon-6,6 Electrospun Nanofibers

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