Tag Archive for: 1 inch QCM

Publication on AWSensors technology

Chemical and Mechanical Properties of Drying Oils during Polymerization

/in , , /by

Author: Gwen dePolo

PhD Thesis: Northwestern University (September 2023)

 

Abstract

Drying oils have been used as a binding medium for oil paints since the 15th century. These oil paints transition from a liquid-like paste to a solid-like film as a result of crosslinks forming between the oil molecules. These reactions have been extensively studied chemically, but other material properties are not as well characterized for drying oils. Oil paints are typically used in complex composite structures where the mechanical properties matter just as much as the chemical properties. This thesis focuses on understanding the evolution of mechanical properties during drying oil polymerization.

 

You may read the full text here.

Publication on AWSensors technology

Tailoring Interactions of Random Copolymer Polyelectrolyte Complexes to Remove Nanoplastic Contaminants from Water

/in , , /by
Authors: Jeremy Wang, Curt Waltmann, Caroline Harms, Sumeng Hu, John Hegarty, Benjamin Shindel, Qifeng Wang, Vinayak Dravid, Kenneth Shull, John M. Torkelson, and Monica Olvera de la Cruz

Journal: Langmuir (2023)

 

Abstract

We investigate the usage of polyelectrolyte complex materials for water remediation purposes, specifically their ability to remove nanoplastics from water, on which there is currently little to no prior research. We demonstrate that oppositely charged random copolymers are effective at quantitatively removing nanoplastic contamination from aqueous solution. The mechanisms underlying this remediation ability are explored through computational simulations, with corroborating quartz crystal microbalance adsorption experiments. We find that hydrophobic nanostructures and interactions likely play an important role.

 

Tailoring Interactions of Random Copolymer Polyelectrolyte Complexes to Remove Nanoplastic Contaminants from Water

 

You may read the full paper here.

Publication on AWSensors technology

Trace Water Effects on Crystalline 1-Ethyl-3-methylimidazolium Acetate

/in , , /by

Authors: Ashlee Aiello, John R. Hoffman, Anthony P. Kotula, Lucas Q. Flagg, Ruipeng Li, and Jeremiah W. Woodcock

Journal: J. Phys. Chem. B (2023)

 

Abstract

Spontaneous room-temperature crystallization of 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) was observed upon removal of trace water. Sample purity was confirmed using analytical nuclear magnetic resonance spectroscopy to ensure that trace water or other contaminants did not produce this observation. Raman spectroscopy and simultaneous quartz crystal microbalance/infrared spectroscopy measurements were used to study molecular reorganization during crystallization and decrystallization using trace water in the form of atmospheric moisture. These experimental results were supplemented with density functional theory calculations that indicate imidazolium cation ring stacking and side chain clustering with an exclusive arrangement of the acetate anion in the cation ring plane upon water removal. Crystal structure formation was confirmed using two-dimensional wide-angle X-ray scattering. This natural crystallization is attributed to the removal of trace water over extended periods of time and calls attention to the molecular-level role of water in the structure of hygroscopic ionic liquid systems.

You may read the full paper here.

Publication on AWSensors technology

Polyelectrolyte Complexes of Random Copolymers and their Applications in Environmental Remediation

/in , , /by

Author: Jeremy Wang

PhD Thesis: Northwestern University (March 2023)

 

Abstract

As polymer science has advanced as a field, so too have the uses for polymeric materials. We encounter polymers and plastics on a daily basis, and while their presence has greatly improved our quality of life, they have also had a profound and often negative impact on our environment. Plastic waste and pollution are currently problems of great concern, and recent trends in terms of micro– and nanoplastic pollution, and chemical pollution of water continue to exacerbate such worries. In this thesis, we explore how polyelectrolyte complexes of random copolymers can be used to effectively address some of these environmental concerns. The combination of charged interactions and disorder of polymer sequence can provide a novel combination of interactions which are well suited for removing contaminants from water, and even promoting the enzymatic degradation of plastic. The results obtained demonstrate that this research into new polymeric materials not only advances our understanding of fundamental polymer properties but yields relevant applications to the issues we encounter in the present day.

 

You may read the full text here.

Scientific publication

The effects of local graphitization on the charging mechanisms of microporous carbon supercapacitor electrodes

/in , , /by

Authors: Huan Yin, Hui Shao, Barbara Daffos, Pierre-Louis Taberna, Patrice Simon.
Journal: Electrochemistry Communications (2022)

 

Abstract

The electrochemical quartz crystal microbalance (EQCM) technique has been used to study the charge mechanisms in two TiC-derived nanoporous carbons (CDC), synthesized at 800℃ and 1100℃. These two carbons have a similar pore size and porous volume, but the CDC prepared at 1100°C shows a more graphitic microstructure. The EQCM study revealed that the charge storage mechanism in the CDC-800 is mainly controlled by a counter-ion adsorption process, while an expanded ion-exchange process was observed for the CDC-1100. Combined with the potential of zero charge (PZC), these measurements suggest a strong interaction between the anions and graphitic carbon. For the first time, we provide experimental evidence that the local carbon structure affects the charge storage mechanism of the electrical double-layer capacitance in high surface area porous carbons.

graphitization graphical abstract

 

You may read the full paper here.