Investigation of the Solidification of Sugar- Beeswax Mixture Using Smart Molds Barry Johnson Suzanne Sachsman Albert Chmelar TAMPL Summer Research Program June 5, 1998

n Background information n Experimental procedure n Data analysis n Closing remarks Overview

Introduction n Two microstructures commonly found are crystalline and amorphous n We investigated both types in this experiment (beeswax and sugar) n Cooling rates greatly affect the resulting microstructure in crystalline solids, and have no affect on the microstructure of non-crystalline solids n This experiment’s goal was to investigate the resulting microstructure of a beeswax/sugar-water solution solid

Background Information n Beeswax is an amorphous solid, and has a homogeneous structure n Crystalline sugar however has a non-homogeneous microstructure n The combination of these two elements into one solid solution creates an interesting mix

Experimental Procedure n Use rapid prototyping to construct smart mold with inserted thermocouple

Experimental Procedure n Add minimum water needed to completely wet sugar n Heat solution on hotplate until the water evaporates and the sugar begins to boil n Monitor temperature of solution using thermocouple n Add beeswax pellets to the boiling sugar solution when desired temperature is obtained n When wax is melted, pour solution into smart mold

Experimental Procedure n Record temperature using FLUKE apparatus over measured time interval n After cooling, remove hardened sample from mold n Examine microstructure of the solid using microscope,CCD camera and image processing software

Quantitative Data n Initial measurements: 4 tablespoons sugar 20 ml water 40 ml beeswax pellets n Viscosity of sugar solution increased as temperature increased n Sugar became darker as temperature increased n Added wax pellets when sugar was amber in color at 180°C n Boiled wax/sugar solution for 15 min while stirring

Cooling Temperature Plot

Results n Resulting solid consisted of two layers Top layer: light brown - beeswax Bottom layer: dark brown - sugar

Beeswax Microstructure n Homogeneous - uniform in structure n Non-crystalline n Surface roughness n Dull

Sugar Microstructure n Crystalline n Impurities (Gas Bubbles) n Hard and brittle n Shiny

Discussion n Sugar melted at high temperatures undergoes transformation n Microstructure provides evidence that wax did not dissolve in sugar solution n In certain proportions, wax may be soluble in sugar solution n Mold with larger surface area and smaller volume creates steep cooling curve

Conclusion n Final microstructure of wax/sugar solution dependent on temperature and proportion of each component n Further research necessary to determine heat treatments for optimal mixture n Additional experimentation could develop heat treatments for desired microstructures