Microscopy technique reveals nanoscale detail of coatings as they dry

July 10, 2020

Dull. Slow. Unchanging. Like watching paint dry. 

But take a closer look at that paint--all the way down to the nanoscale--and there's a lot more going on than you might think.  

Researchers in the Gilchrist Laboratory in Lehigh University's P.C. Rossin College of Engineering and Applied Science are observing the evolution of coatings as they dry with groundbreaking microscale precision. Their results were recently published in Scientific Reports

Thin film coatings do much more than spruce up walls. For example, they can be used as pharmaceutical devices in edible films, similar to those to deliver drugs used to fight the opioid epidemic. How these coatings dry can change their properties, which is especially important for films used in drug delivery. 

In their paper, "Chemical vs. mechanical microstructure evolution in drying colloid and polymer coatings," the Lehigh researchers looked at how particles rearrange themselves during drying when their interactions are tuned. These particles behaved as a surrogate for the active pharmaceutical ingredient in a drug delivery film.

Graduate student Titiporn Kaewpetch looks directly inside these films using high speed confocal laser scanning microscopy to take thousands of images that give nanoscale details of how particles flow and assemble during drying. Gigabytes of data for each film are rendered to reveal their 3-D structure, giving simulation-like detail on the otherwise hidden internal processes that happen. 

The researchers found that when particles attract each other, they form a scaffold that buckles and breaks during drying due to the motion of the top interface. "The microstructure for attractive particles at each point during drying is related to the history of the film evolution," says James Gilchrist, a professor in the Department of Chemical and Biomolecular Engineering. Their 3-D analysis of the microstructure evolution reveals clear signatures of this process throughout drying as compared with those where particles are repulsive.

"In real drug delivery systems, there are many ingredients interacting with each other, always changing concentration and their interactions throughout drying," says Gilchrist. "By reducing this process to the essential ingredients, we can see these interactions as they happen. This may allow new insights into manufacturing of these films."

This paper is based upon work supported by the National Science Foundation (grant No. 1936541). Kaewpetch is supported by the Royal Thai Scholars program.

Related Links:

-end-


Lehigh University

Related Evolution Articles from Brightsurf:

Seeing evolution happening before your eyes
Researchers from the European Molecular Biology Laboratory in Heidelberg established an automated pipeline to create mutations in genomic enhancers that let them watch evolution unfold before their eyes.

A timeline on the evolution of reptiles
A statistical analysis of that vast database is helping scientists better understand the evolution of these cold-blooded vertebrates by contradicting a widely held theory that major transitions in evolution always happened in big, quick (geologically speaking) bursts, triggered by major environmental shifts.

Looking at evolution's genealogy from home
Evolution leaves its traces in particular in genomes. A team headed by Dr.

How boundaries become bridges in evolution
The mechanisms that make organisms locally fit and those responsible for change are distinct and occur sequentially in evolution.

Genome evolution goes digital
Dr. Alan Herbert from InsideOutBio describes ground-breaking research in a paper published online by Royal Society Open Science.

Paleontology: Experiments in evolution
A new find from Patagonia sheds light on the evolution of large predatory dinosaurs.

A window into evolution
The C4 cycle supercharges photosynthesis and evolved independently more than 62 times.

Is evolution predictable?
An international team of scientists working with Heliconius butterflies at the Smithsonian Tropical Research Institute (STRI) in Panama was faced with a mystery: how do pairs of unrelated butterflies from Peru to Costa Rica evolve nearly the same wing-color patterns over and over again?

Predicting evolution
A new method of 're-barcoding' DNA allows scientists to track rapid evolution in yeast.

Insect evolution: Insect evolution
Scientists at Ludwig-Maximilians-Universitaet (LMU) in Munich have shown that the incidence of midge and fly larvae in amber is far higher than previously thought.

Read More: Evolution News and Evolution Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.