spontaneously filled by the action of capillary forces. The response of the molecular-sieve fibers to the applied electric field was observed by an optical microscope (Leitz Orthoplan) connected to a digital camera (Panasonic).Preparation of Oriented Thin Films: A cell was designed for the deposition experiment, as shown in Figure 2. The cell consisted of two copper plates, 25 mm long, held apart by a 2 mm non-conducting spacer. A 2 mm wide glass slide was placed between the electrodes. A dilute AlPO 4 -5 colloidal suspension of concentration 2 mg fibers/ mL Fomblin was loaded onto the 2 mm wide glass slide to form a thin, liquid layer. A DC electric field of 10 kV cm ±1 was then applied for 15 min. After 15 min, most of the Fomblin leaked into the space between the electrodes and spacer. To observe the oriented film with electron microscopy, residual Fomblin was removed by heating at 300 C in an oven for one hour. The deposition process was repeated 5 times to achieve high coverage of the fibers in the glass slide.Dye-Loaded AlPO 4 -5 Crystals and UV-Vis Spectra Measurement: The AlPO 4 -5 crystals were first calcined at 600 C for 10 h in a continuous flow of oxygen to remove organic material from the pores. PNA (99 %, from Aldrich) was then incorporated into the pores of the crystals by gas loading at 100 C and by autogenous pressurization after being left overnight. The dye-loaded crystals appeared yellow. Excess PNA was then washed from the exterior of the crystals by dispersing the crystals in ethanol. Crystals were then collected by centrifugation at 15 300 rpm for one hour. The crystals remained yellow after washing. A dye-loaded oriented film was created by 10 depositions cycles from a suspension of 5 mg fibers per mL of Fomblin. The UV-vis transmission spectra were collected by a PerkinElmer Lambda 900 UV/Vis/Near-infrared spectrometer equipped with an adjustable polarizer.