Determination of Contact Angles of Nanosized Silica Particles by Multi-Angle Single-Wavelength Ellipsometry

2007 ◽  
Vol 60 (9) ◽  
pp. 651 ◽  
Author(s):  
Timothy N. Hunter ◽  
Graeme J. Jameson ◽  
Erica J. Wanless

The determination of nanoparticle wettability is an area of great practical importance to materials science and engineering fields. There has been some recent interest in using spectroscopic analysis to indirectly categorize behaviour of monolayers, using the reflective and refractive properties of immersed particles. A method is developed here to calculate specific contact information for nanoparticles at an air–water interface, using single wavelength ellipsometry. A two-layer model is used that considers the refractive index of the immersed and non-immersed particle portions. Pressure–area isotherms and Brewster angle images were used to confirm and categorize the nature of a packed monolayer, and ψ and Δ measurements taken of the interface. Immersion thickness was calculated and related to an equilibrium contact angle, and combined thickness data for the two layers was successfully related to the diameter of the particles.

2000 ◽  
Vol 632 ◽  
Author(s):  
Eric Werwa

ABSTRACTA review of the educational literature on naive concepts about principles of chemistry and physics and surveys of science museum visitors reveal that people of all ages have robust alternative notions about the nature of atoms, matter, and bonding that persist despite formal science education experiences. Some confusion arises from the profound differences in the way that scientists and the lay public use terms such as materials, metals, liquids, models, function, matter, and bonding. Many models that eloquently articulate arrangements of atoms and molecules to informed scientists are not widely understood by lay people and may promote naive notions among the public. Shifts from one type of atomic model to another and changes in size scales are particularly confusing to learners. People's abilities to describe and understand the properties of materials are largely based on tangible experiences, and much of what students learn in school does not help them interpret their encounters with materials and phenomena in everyday life. Identification of these challenges will help educators better convey the principles of materials science and engineering to students, and will be particularly beneficial in the design of the Materials MicroWorld traveling museum exhibit.


2021 ◽  
Vol 22 (9) ◽  
pp. 4543
Author(s):  
Xuan-Hung Pham ◽  
Seung-min Park ◽  
Bong-Hyun Jun

Nano/micro particles are considered to be the most valuable and important functional materials in the field of materials science and engineering [...]


MRS Bulletin ◽  
1992 ◽  
Vol 17 (9) ◽  
pp. 18-21 ◽  
Author(s):  
R. Abbaschian

Materials science and engineering (MSE), as a field as well as a discipline, has expanded greatly in recent years and will continue to do so, most likely at an even faster pace. It is now well-accepted that materials are crucial to the national defense, to the quality of life, and to the economic security and competitiveness of the nation. Mankind has recognized the importance of manmade materials to the quality of life for many centuries. In many cases, the security and defense of tribes and nations have substantially depended on the availability of materials. It is not surprising that historical periods have been named after materials—the Bronze Age, the Iron Age, etc. The major requirements from materials in those days were their properties and performance. Today, in this age of advanced materials, the importance of materials to defense and quality of life has not changed. However, the critical role of materials has taken an additional dimension: it has become essential to enhancing industrial competitiveness.The knowledge base within MSE has also expanded vastly throughout these years and continues to do so at an increasing rate. We are constantly gaining a deeper understanding of the fundamental nature of materials, developing new ways to produce and shape them for applications extending from automobiles to supersonic airplanes, optoelectronic devices to supercomputers, hip implants to intraocular lenses, or from household appliances to gigantic structures. We are also learning that, in many of these applications, we need to depend on the combinations or composites of different classes of materials (metals, ceramic, polymers, and electronic materials) to enhance their properties.


Sign in / Sign up

Export Citation Format

Share Document