Synthesis and structure–property relationships of polypropylene-g-polystyrene and polypropylene-g-poly(n-butyl acrylate) graft copolymers with well-defined molecular structures

Polymer ◽  
2013 ◽  
Vol 54 (14) ◽  
pp. 3641-3653 ◽  
Author(s):  
Lu Wang ◽  
Hongfan Yang ◽  
Haiying Tan ◽  
Kun Yao ◽  
Jiang Gong ◽  
...  
2012 ◽  
Vol 1425 ◽  
Author(s):  
Michael P. Krein ◽  
Bharath Natarajan ◽  
Linda S. Schadler ◽  
L. C. Brinson ◽  
Hua Deng ◽  
...  

ABSTRACTPolymer nanocomposites (PNC) are complex material systems in which the dominant length scales converge. Our approach to understanding nanocomposite tradespace uses Materials Quantitative Structure-Property Relationships (MQSPRs) to relate molecular structures to the polar and dispersive components of corresponding surface tensions. If the polar and dispersive components of surface tensions in the nanofiller and polymer could be determined a priori, then the propensity to aggregate and the change in polymer mobility near the particle could be predicted. Derived energetic parameters such as work of adhesion, work of spreading and the equilibrium wetting angle may then used as input to continuum mechanics approaches that have been shown able to predict the thermomechanical response of nanocomposites and that have been validated by experiment. The informatics approach developed in this work thus enables future in silico nanocomposite design by enabling virtual experiments to be performed on proposed nanocomposite compositions prior to fabrication and testing.


2018 ◽  
Vol 8 (10) ◽  
pp. 1972 ◽  
Author(s):  
Giorgio De Luca ◽  
Roberta Amuso ◽  
Alberto Figoli ◽  
Raffaella Mancuso ◽  
Lucio Lucadamo ◽  
...  

Polymerizable quaternary ammonium salts (PQASs) were synthesized in a previous work and some of them were used as surfactants in the antimicrobial coating of commercial membranes. Herein, the electrostatic charges, maximum length, and aspect ratio of these antibacterial surfactants were calculated with the aim of investigating the relationship between the properties, recognized to control the biocidal activity of these molecules, and the molecular structures. The effect of the water molecules was considered through a quantum and molecular mechanics approach. The correlation between the number of carbons in the main aliphatic chain of PQAS and the above properties was investigated, by finding that the net charge on the ammonium group does not increase as the number of carbons in the aliphatic chain increase. Thus, although this number influences the antibacterial activity of the surfactants, this influence is not correlated with an increase of the ammonium positive charge. Unlike the partial charges, a different trend was obtained for the surfactants’ maximum length and aspect ratio in agreement with the experimental behavior. As this modeling does not use empirical or adjustable parameters, it can assist the synthetic plan of new structures for surface functionalization, in order to improve the biofouling resistance of the membranes.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yangyang Wan ◽  
Fernando Ramirez ◽  
Xu Zhang ◽  
Thuc-Quyen Nguyen ◽  
Guillermo C. Bazan ◽  
...  

AbstractConjugated polyelectrolytes (CPEs), comprised of conjugated backbones and pendant ionic functionalities, are versatile organic materials with diverse applications. However, the myriad of possible molecular structures of CPEs render traditional, trial-and-error materials discovery strategy impractical. Here, we tackle this problem using a data-centric approach by incorporating machine learning with high-throughput first-principles calculations. We systematically examine how key materials properties depend on individual structural components of CPEs and from which the structure–property relationships are established. By means of machine learning, we uncover structural features crucial to the CPE properties, and these features are then used as descriptors in the machine learning to predict the properties of unknown CPEs. Lastly, we discover promising CPEs as hole transport materials in halide perovskite-based optoelectronic devices and as photocatalysts for water splitting. Our work could accelerate the discovery of CPEs for optoelectronic and photocatalytic applications.


2011 ◽  
Vol 67 (6) ◽  
pp. 560-568 ◽  
Author(s):  
Xiaogang Liu ◽  
Jacqueline M. Cole ◽  
Paul G. Waddell ◽  
Tze-Chia Lin

The molecular structures of three compounds, LD 425 (C13H14N2O3) (1), LD 489 (C15H15F3N2O2) (2) and LD 473 (C17H19F3N2O) (3), are determined by single-crystal X-ray diffraction (XRD) at 180 K. Azacoumarins (1) and (2) possess para-quinoidal bond-length patterns in their benzene rings due to intramolecular charge transfer (ICT) from these rings to the adjoining rings. In contrast, substitution of O with N within the coumarin heterocycle, to form a 2-quinolone, results in the suppression of this ICT effect. Instead, charge transfer within the heterocycle is shown to become more pronounced. Resonance theory is employed to discuss these bond pattern differences and characteristic spectral blue shifts in relation to their coumarin analogues. The application of this theory offers an intuitive understanding of the structure–property relationships in azacoumarins and 2-quinolones which is further supported by quantum chemical calculations. Such an understanding is important for recognizing ICT mechanisms in these compounds which can then be used to facilitate the molecular design of new laser dyes with the desired spectral shifts.


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