Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Understanding the way liquid spreads through paper

30.11.2016

A team of researchers from India have created a model to explain how liquid diffuses through paper which has applications in medical testing and perfume manufacturing

Molecules move randomly, colliding with each other in continual motion. You can even smell this process at times; it's how perfume spreads across a room when the air is still. The process is termed diffusion and the theory of diffusion can be applied to liquid spreading through paper, too - a process at work in a range of everyday products, from ink pens to paper sampling patches for medical tests.


Investigators documented spreading of ink on a filter paper of Whatman Grade 1, and analyzed the process with a scanning electron microscope. Scanning micrographic results show paper fiber distribution, along with the micro-particle-image-velocimetry measure of random liquid movement through the network. Researchers conclude this evidence confirms diffusive dynamics at work in the spread of liquid through a paper matrix.

Credit: Suman Chakrabort

Now, a team of researchers in India have developed a model that deepens their conceptual grasp of how liquids spread through paper.

"Liquid spreading in a paper is essentially random liquid motion through a randomly distributed network of fibers," said Suman Chakraborty, lead researcher of the investigation at the Indian Institute of Technology Kharagpur, and the Advancement Technology Development Centre, both located in Kharagpur, India. Results are published this week in Applied Physics Letters, from AIP Publishing.

Diffusion is a well-known process. But the team's elaboration of diffusion theory in the context of paper-liquid interactions, which pose tortuous fiber networks to transport dynamics, is novel and reveals new theoretical detail. In their experiment, the researchers observed ink spreading on filter paper using a scanning electron microscope.

The team mapped liquid spreading dynamics from a single fiber capillary to a larger network of the fibers. They then computed the resulting transport characteristics, with results confirming a generalized unified perspective of diffusion at work in the process of liquid moving through a paper matrix. Scanning micrographic images show paper fiber distributions, along with the micro-particle-image-velocimetry measure of random liquid movement through the network.

"Our study reveals that, despite such diversified uses of paper interacting with liquids, there is a fundamental uniqueness of liquid spreading through paper leading toward a general and unified theory about it," Chakraborty said.

The theory holds that molecules of a liquid move through the fiber network of paper following the principles of universal diffusive dynamics. "Paper is constituted of a network of fibers distributed randomly," said Chakraborty. "As a consequence, random motion of the liquid in all possible directions occurs. We know molecules move randomly and collide with each other, and this is the premise of diffusion."

Despite wide use of liquid-infused paper technologies, there are gaps in the understanding of the basic science behind its behavior. Chakraborty and his students, Kaustav Chaudhury and Shantimoy Kar, help fill that gap.

By understanding liquid spread in the paradigm of diffusion, scientists can control it more precisely to create and refine new products that involve liquid spreading through paper. For example, current markets have validated an important potential property of paper: acting as the essential building block of a rapid diagnostic kit in an ultra-low-cost paradigm.

Examples of this application include pregnancy test strips; alkalinity or acidity tests of beauty and baby soaps using a paper strip; paper-strips for checking water quality; and medical diagnosis aided by paper-strip tests of urine, saliva and blood. The author's diffusion model of liquid spreading in paper can also improve papers and inks used for writing, drawing and painting.

Next, the investigators plan to develop smart and compact technologies for diagnostic purposes, advancing the existing paper based platforms.

"The key objectives are to obtain rapid results at the expense of low costs. To this end, the paper shows a promising prospect of being a tool to serve both the objectives. The present work, as we believe, will pave the way for the design and development of the paper-based technologies to serve a wider public," Chakraborty said.

###

The article, "Diffusive dynamics on paper matrix," is authored by Kaustav Chaudhury, Shantimoy Kar and Suman Chakraborty. The article will appear in the journal Applied Physics Letters on November 29, 2016 (DOI: 10.1063/1.4966992). After that date, it can be accessed at: http://scitation.aip.org/content/aip/journal/apl/109/20/10.1063/1.4966992

About the journal:

Applied Physics Letters features concise, rapid reports on significant new findings in applied physics. The journal covers new experimental and theoretical research on applications of physics phenomena related to all branches of science, engineering, and modern technology.

Media Contact

AIP Media
media@aip.org
301-209-3090

 @jasonbardi

http://www.aip.org 

AIP Media | EurekAlert!

More articles from Physics and Astronomy:

nachricht Unconventional superconductor may be used to create quantum computers of the future
19.02.2018 | Chalmers University of Technology

nachricht Hubble sees Neptune's mysterious shrinking storm
16.02.2018 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Contacting the molecular world through graphene nanoribbons

19.02.2018 | Materials Sciences

When Proteins Shake Hands

19.02.2018 | Materials Sciences

Cells communicate in a dynamic code

19.02.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>