Two Methods for Measuring Index of Refraction

Sweet Experiments in Physics and Optics with Candy Glass

Materials Preparation & Processing

1. Candy making

2. Phase Diagrams

3. Fiber Drawing

Properties

4. Crystallization and Kinetics

(moisture and thermal mediated)*

5. Refractive Index

6.. Nano-carbon Fluorescence

7. Thermal Analysis

8. Electrical Conductivity

9. Thermal Conductivity

Message:

We have multiple activities to engage students in hands-on glass science. The experiments are

linked to form a mini-curriculum on which the student can build from the basic materials preparation

(cooking) to increasingly more complicated experiments including characterization methods. All

experiments can be done within the resources of a high school lab or even the home. The approach is

open ended, encouraging the student to experience the joy of building and discovery. Many could be

appropriate for the undergraduate science lab. These and other activities are available to all on our

IMI website at: http://www.lehigh.edu/imi

Abstract: We present a collection hands-on experiment and home-built apparatus designed to explore physics and “real” glass science through a common and accessible sugar glass also known as hard candy. Experiments are all low-cost and inter-

related and include: synthesis, phase diagram, refractive index measurement, nano-carbon fluorescence and crystallization phenomena, as well as apparatus for differential thermal analysis, electrical conductivity and “optical fiber” drawing. Most of the

experiments can be assembled in a high school or college lab with minimal cost. The scientific content of these experiments progresses systematically, providing an environment to develop an understanding of glassy materials and participate in the process

of scientific inquiry and discovery through experimentation, within a framework of active prolonged engagement.

The Making of Hard Candy

(Glass) – Material Synthesis

Phenomenological approach

Sucrose, Corn Syrup and Water are

combined and cooked-

• first to dissolve into a single liquid phase &

• then to remove most of the water.

Boiling temp provides measure of the water

content. Boil to ~ 150° C.

Cost ~ $5 in materials

for many batches Data from Food Industries Manual, 24th ed, (1997).

Materials Preparation

Phase Diagrams

Elect. conductivity in Glass

Curriculum activities

www.lehigh.edu/imi

International Materials Institute for New Functionality in Glass

Sponsored by US National Science Foundation

1. W. R. Heffner and H. Jain, “Building a Low Cost, Hands-on Learning Curriculum on Glass Science and Engineering using

Candy Glass” in MRS Proceedings 1233 , Boston, 2009, edited by M. M. Patterson (Materials Research Society, 2010).

2. W. R. Heffner and H Jain, “Low-Cost, Experimental Curriculum in Materials Science Using Candy Glass Part 2: Home-

Built Apparatuses” in MRS Proceedings 1657, Boston, 2014, (Materials Research Society, 2014).

Both papers as well as additional information are available on the IMI website at: http://www.lehigh.edu/imi

Acknowledgement: This work has been supported by IMI-NFG, Lehigh University through National Science Foundations (NSF) Grants : DMR-0409588 and DMR-0844014

References to Additional Information

Differential Thermal Analysis - DTA

William R. Heffner and Himanshu JainIMI-NFG, Lehigh University, Bethlehem, PA

Fluorescence – A Carbon Nano-dot Experiment

Quantitative Fluorescence Monitor

Thermal Conductivity

Crystallization in Glass

Problem with Sucrose alone: Very prone to crystallization at low water,

Which is why we add corn syrup (glucose and long chain dextrins).

Simple DTA can be constructed with some test tubes, heated temperature bath, thermocouples and some simple electronics

to measure the differential and bath temperatures. Open students to Tg and associated relaxation processes.

Thermal Conductivity Apparatus relies on measuring

small differential temperatures as the DTA. Good

correlation with literature values of common insulators

was obtained.

Fluorescence experiment introduces student to the field of nan-dot fluorescence

and the characteristic shift in emission with excitation wavelength – a great

gateway into other open-ended investigations.

Fiber Drawing Tower