Sample Environments
Typical sample thickness for SANS measurements is of order of 1 mm. Liquid samples (polymer solutions, microemulsions) are often contained in quartz cells into which syringes can be inserted. Solid polymer samples are usually melt pressed above their softening (glass-rubber) temperature, then confined in special cells between quartz windows. Flexibility of design for some instruments allows the use of typical size samples under temperature control or bulky sample environments. Temperature is easily varied between ambient temperature and 200oC using heating cartridges or between -10oC and room temperature using a circulating bath. Other sample environment equipment such as low-temperature cryostats (4 to 350 K) and electromagnets (1-10Teslas) are sometime made available to users. Various shear cells (Couette, plate-and-plate, etc) are helping probe "soft" materials at the molecular level in order to better understand their rheology. A few pressure cells are also finding wide use for investigations of compressibility effects on the thermodynamics of phase separation as well as on structure and morphology.