Universality in Spatio-Temporal High-Mobility Domains Across the Glass Transition from Bulk Polymers to Single Chains

2020 ◽  
Vol 53 (21) ◽  
pp. 9375-9385
Author(s):  
Lorena Alzate-Vargas ◽  
Nicolas Onofrio ◽  
Alejandro Strachan
Keyword(s):  
Glass Transition ◽  
High Mobility ◽  
Bulk Polymers ◽  
Spatio Temporal

scholarly journals Spatio-temporal heterogeneities in nanosegregated single-molecule polymeric nanoparticles

Soft Matter ◽  
2020 ◽  
Vol 16 (19) ◽  
pp. 4584-4590
Author(s):  
Petra Bačová ◽  
Emmanouil Glynos ◽  
Spiros H. Anastasiadis ◽  
Vagelis Harmandaris
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Single Molecule ◽  
Polymeric Nanoparticles ◽  
Spatio Temporal

Nanoparticles with nanosegregated, dynamically heterogeneous domains can be designed by combining incompatible dynamically asymmetric polymers of different glass transition temperature in a mikto-arm architecture.

Molecular Simulation of the Water Uptake and Glass Transition of Sulfonated Copolyimides as Polyelectrolytes for Fuel Cell Applications

2004 ◽  
Vol 856 ◽  
Author(s):  
N. Hu ◽  
A.T. Hsu
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Water Uptake ◽  
Water Solubility ◽  
High Mobility ◽  
Disulfonic Acid ◽  
Gcmc Simulation ◽  
Simulation Results ◽  
Grand Canonical ◽  
Specific Volumes

ABSTRACTMolecular dynamics and Grand Canonical Monte Carlo simulations have been used to obtain the glass transition temperatures and the water uptake for polyimides synthesized from Naphthalene-1, 4, 5, 8-tetracaboxylic dianhydride (NTDA), 2, 2'-benzidinedisulfonic acid (BDSA), 4, 4'-diaminodiphenylether-2, 2'-disulfonic acid (ODADS), and non-sulfonated diamine monomers. The glass transition temperature Tgs of these polyimide copolymers have been determined from plots of specific volumes versus temperatures above and below Tgs. The simulation results suggest that the ODADS-based polyimide membranes have lower Tgs and better mechanical properties than the BDSA-based polyimides, which can be attributed to high mobility of the backbones of ODADS as supported by the vectorial autocorrelation function (VACF) results of this study. In addition, comparisons of the simulated Tgs for ODADS-based polyimides of various degrees of hydration show that water content in polyimides may enhance their mechanical properties by lowering the Tgs. In the case of water uptake of these polyimide copolymers, the GCMC simulation results indicate better water solubility for more sulfonated polymers.

scholarly journals Linking Glass‐Transition Behavior to Photophysical and Charge Transport Properties of High‐Mobility Conjugated Polymers

2020 ◽  
pp. 2007359
Author(s):  
Mingfei Xiao ◽  
Aditya Sadhanala ◽  
Mojtaba Abdi‐Jalebi ◽  
Tudor H. Thomas ◽  
Xinglong Ren ◽  
...  
Keyword(s):  
Glass Transition ◽  
Conjugated Polymers ◽  
Charge Transport ◽  
Transport Properties ◽  
High Mobility ◽  
Transition Behavior

scholarly journals Temperate grass allergy season defined by spatio-temporal shifts in airborne pollen communities

2018 ◽  
Author(s):  
Georgina L. Brennan ◽  
Caitlin Potter ◽  
Natasha de Vere ◽  
Gareth W. Griffith ◽  
Carsten A. Skjøth ◽  
...  
Keyword(s):  
Grass Pollen ◽  
High Throughput Sequencing ◽  
Airborne Pollen ◽  
High Mobility ◽  
Economic Benefits ◽  
Taxonomic Composition ◽  
Poaceae Pollen ◽  
Pollen Exposure ◽  
Spatio Temporal ◽  
Seasonal Pollen

AbstractGrass pollen is the world’s most harmful outdoor aeroallergen and sensitivity varies between species. Different species of grass flower at different times, but it is not known how airborne communities of grass pollen change in time and space. Persistence and high mobility of grass pollen could result in increasingly diverse seasonal pollen communities. Conversely, if grass pollen does not persist for an extended time in the air, shifting pollen communities would be predicted throughout the summer months. Here, using targeted high throughput sequencing, we tracked the seasonal progression of airborne Poaceae pollen biodiversity across Britain, throughout the grass allergy season. All grass genera displayed discrete, temporally restricted peaks of pollen incidence which varied with latitude, revealing that the taxonomic composition of grass pollen exposure changes substantially across the allergy season. By developing more refined aeroallergen profiling, we predict that our findings will facilitate the exploration of links between taxon-specific exposure of harmful grass pollen and disease, with concomitant socio-economic benefits.

scholarly journals The Spatio-Temporal Characteristics and Influencing Factors of Covid-19 Spread in Shenzhen, China—An Analysis Based on 417 Cases

2020 ◽  
Vol 17 (20) ◽  
pp. 7450
Author(s):  
Shirui Liu ◽  
Yaochen Qin ◽  
Zhixiang Xie ◽  
Jingfei Zhang
Keyword(s):  
Nearest Neighbor ◽  
High Mobility ◽  
Time Interval ◽  
Linear Regression Method ◽  
Index Method ◽  
Temporal Characteristics ◽  
Global Pandemic ◽  
Ellipse Method ◽  
Long Time ◽  
Spatio Temporal

The global pandemic of COVID-19 has made it the focus of current attention. At present, the law of COVID-19 spread in cities is not clear. Cities have long been difficult areas for epidemic prevention and control because of the high population density, high mobility of people, and high frequency of contacts. This paper analyzed case information for 417 patients with COVID-19 in Shenzhen, China. The nearest neighbor index method, kernel density method, and the standard deviation ellipse method were used to analyze the spatio-temporal characteristics of the COVID-19 spread in Shenzhen. The factors influencing that spread were then explored using the multiple linear regression method. The results show that: (1) The development of COVID-19 epidemic situation in Shenzhen occurred in three stages. The patients showed significant hysteresis from the onset of symptoms to hospitalization and then to diagnosis. Prior to 27 January, there was a relatively long time interval between the onset of symptoms and hospitalization for COVID-19; the interval decreased thereafter. (2) The epidemic site (the place where the patient stays during the onset of the disease) showed an agglomeration in space. The degree of agglomeration constantly increased across the three time nodes of 31 January, 14 February, and 22 February. The epidemic sites formed a “core area” in terms of spatial distribution and spread along the “northwest–southeast” direction of the city. (3) Economic and social factors significantly impacted the spread of COVID-19, while environmental factors have not played a significant role.

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