Grafting reactions onto poly(organophosphazenes). IV. Light-induced graft copolymerization of organic polymers containing free acid or basic functionalities onto poly[bis(4-benzylphenoxy)phosphazene]

1995 ◽  
Vol 56 (6) ◽  
pp. 747-756 ◽  
Author(s):  
Francesco Minto ◽  
Mario Gleria ◽  
Pietro Bortolus ◽  
Luca Fambri ◽  
Alessandro Pegoretti
Keyword(s):  
Graft Copolymerization ◽  
Free Acid ◽  
Organic Polymers ◽  
Grafting Reactions

Grafting reactions onto poly(organophosphazenes)—ii. photo-induced graft copolymerization of polymethylmethacrylate onto poly[bis(4-isopropylphenoxy)phosphazene]

1992 ◽  
Vol 28 (2) ◽  
pp. 167-173 ◽  
Author(s):  
Francesco Minto ◽  
Marco Scoponi ◽  
Luca Fambri ◽  
Mario Gleria ◽  
Pietro Bortolus ◽  
...  
Keyword(s):  
Graft Copolymerization ◽  
Grafting Reactions

Calcium ion imaging in plant cells

1993 ◽  
Vol 51 ◽  
pp. 132-133
Author(s):  
Peter K. Hepler ◽  
Dale A. Callaham
Keyword(s):  
Plant Cell Wall ◽  
Cytoplasmic Membrane ◽  
Fluorescent Dyes ◽  
Free Acid ◽  
Methyl Esters ◽  
Free Calcium ◽  
Local Concentration ◽  
Ion Imaging ◽  
Membrane Compartments ◽  
Free Acid Form

Calcium ions (Ca) participate in many signal transduction processes, and for that reason it is important to determine where these ions are located within the living cell, and when and to what extent they change their local concentration. Of the different Ca-specific indicators, the fluorescent dyes, developed by Grynkiewicz et al. (1), have proved most efficacious, however, their use on plants has met with several problems (2). First, the dyes as acetoxy-methyl esters are often cleaved by extracellular esterases in the plant cell wall, and thus they do not enter the cell. Second, if the dye crosses the plasma membrane it may continue into non-cytoplasmic membrane compartments. Third, even if cleaved by esterases in the cytoplasm, or introduced as the free acid into the cytoplasmic compartment, the dyes often become quickly sequestered into vacuoles and organelles, or extruded from the cell. Finally, the free acid form of the dye readily complexes with proteins reducing its ability to detect free calcium. All these problems lead to an erroneous measurement of calcium (2).

Non-linear spin-density excitations in 1-D organic polymers

1983 ◽  
Vol 44 (8) ◽  
pp. 953-955 ◽  
Author(s):  
C. Aslangul ◽  
D. Saint-James
Keyword(s):  
Spin Density ◽  
Organic Polymers ◽  
Non Linear

Intensification of Extraction of Thermolabile Organic Polymers into a Liquid Electrolyte

1998 ◽  
Vol 29 (1-3) ◽  
pp. 140-145
Author(s):  
R. Sh. Vainberg ◽  
S. A. Bogdanov ◽  
N. D. Butskii
Keyword(s):  
Liquid Electrolyte ◽  
Organic Polymers

Effect of Electron Flux on the Degradation of Organic Polymers in a Simulated GEO Environment

2021 ◽  
Author(s):  
Daniel P. Engelhart ◽  
Vanessa J. Murray ◽  
Elena A. Plis ◽  
Karin Fulford ◽  
Dale C. Ferguson ◽  
...  
Keyword(s):  
Electron Flux ◽  
Organic Polymers

Combining First-Principles and Data Modeling for the Accurate Prediction of the Refractive Index of Organic Polymers

2017 ◽  
Author(s):  
Mohammad Atif Faiz Afzal ◽  
Chong Cheng ◽  
Johannes Hachmann
Keyword(s):  
First Principles ◽  
Data Modeling ◽  
Accurate Prediction ◽  
Index Of Refraction ◽  
Structure Theory ◽  
Organic Polymers ◽  
Number Density ◽  
Lorenz Equation ◽  
In Silico Studies ◽  
Wide Range

Organic materials with a high index of refraction (RI) are attracting considerable interest due to their potential application in optic and optoelectronic devices. However, most of these applications require an RI value of 1.7 or larger, while typical carbon-based polymers only exhibit values in the range of 1.3–1.5. This paper introduces an efficient computational protocol for the accurate prediction of RI values in polymers to facilitate in silico studies that an guide the discovery and design of next-generation high-RI materials. Our protocol is based on the Lorentz-Lorenz equation and is parametrized by the polarizability and number density values of a given candidate compound. In the proposed scheme, we compute the former using first-principles electronic structure theory and the latter using an approximation based on van der Waals volumes. The critical parameter in the number density approximation is the packing fraction of the bulk polymer, for which we have devised a machine learning model. We demonstrate the performance of the proposed RI protocol by testing its predictions against the experimentally known RI values of 112 optical polymers. Our approach to combine first-principles and data modeling emerges as both a successful and highly economical path to determining the RI values for a wide range of organic polymers.

Sign in / Sign up

Export Citation Format

Share Document