TY - JOUR
T1 - Observations of layer growth in synthetic zeolites by field emission scanning electron microscopy
AU - Bazzana, S.
AU - Dumrul, S.
AU - Warzywoda, J.
AU - Hsiao, L.
AU - Klass, L.
AU - Knapp, M.
AU - Rains, J. A.
AU - Stein, E. M.
AU - Sullivan, M. J.
AU - West, C. M.
AU - Woo, J. Y.
AU - Sacco, A.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2002
Y1 - 2002
N2 - Field emission scanning electron microscopy (FE-SEM) has been used to image the crystal growth-induced surface features of synthetic zeolites. The capability of FE-SEM to image layers of nanometer scale thickness in zeolites A, X, and Silicalite has been demonstrated by comparing atomic force microscope (AFM) and FE-SEM images of their surface topography. Layers on the {100} faces of zeolite A, {111} faces of zeolite X, and {100} and {010} faces of Silicalite with AFM measured thickness of ∼1.2, ∼1.5, ∼1-2, and ∼1-2 nm, respectively were successfully imaged by FE-SEM using crystals coated with thin Cr films. Also, FE-SEM could discern layers on the uncoated crystals but the resulting images were characterized by much poorer topographic contrast. In addition, layers on the {110} zeolite A surfaces hitherto not reported have been imaged by FE-SEM. The presence of growth terraces on the {110} faces has been related to the high ratio of the rate of surface nucleation to the rate of lateral propagation of layers occurring on these surfaces near the end of crystallization. The FE-SEM images of layers on the basal planes of cylindrical zeolite L crystals have been also acquired and also discussed in context with the previously hypothesized spiral growth mechanism on these surfaces.
AB - Field emission scanning electron microscopy (FE-SEM) has been used to image the crystal growth-induced surface features of synthetic zeolites. The capability of FE-SEM to image layers of nanometer scale thickness in zeolites A, X, and Silicalite has been demonstrated by comparing atomic force microscope (AFM) and FE-SEM images of their surface topography. Layers on the {100} faces of zeolite A, {111} faces of zeolite X, and {100} and {010} faces of Silicalite with AFM measured thickness of ∼1.2, ∼1.5, ∼1-2, and ∼1-2 nm, respectively were successfully imaged by FE-SEM using crystals coated with thin Cr films. Also, FE-SEM could discern layers on the uncoated crystals but the resulting images were characterized by much poorer topographic contrast. In addition, layers on the {110} zeolite A surfaces hitherto not reported have been imaged by FE-SEM. The presence of growth terraces on the {110} faces has been related to the high ratio of the rate of surface nucleation to the rate of lateral propagation of layers occurring on these surfaces near the end of crystallization. The FE-SEM images of layers on the basal planes of cylindrical zeolite L crystals have been also acquired and also discussed in context with the previously hypothesized spiral growth mechanism on these surfaces.
UR - http://www.scopus.com/inward/record.url?scp=0036938711&partnerID=8YFLogxK
U2 - 10.1016/s0167-2991(02)80019-2
DO - 10.1016/s0167-2991(02)80019-2
M3 - Article
AN - SCOPUS:0036938711
VL - 142 A
SP - 117
EP - 124
JO - Studies in Surface Science and Catalysis
JF - Studies in Surface Science and Catalysis
SN - 0167-2991
ER -