教師資料查詢 | 類別: 期刊論文 | 教師: 鄭廖平 CHENG, LIAO-PING (瀏覽個人網頁)

標題:Effect of polar rotation on the formation of porous poly(vinylidene fluoride) membranes by immersion precipitation in an alcohol bath
學年105
學期1
出版(發表)日期2016/09/01
作品名稱Effect of polar rotation on the formation of porous poly(vinylidene fluoride) membranes by immersion precipitation in an alcohol bath
作品名稱(其他語言)
著者Hsu-Hsien Chang, Liang-Kuei Chang, Cheng-Dau Yang, Dar-Jong Lin, Liao-Ping Cheng
單位
出版者
著錄名稱、卷期、頁數Journal of Membrane Science, 513, 186-196
摘要Microporous poly(vinylidene fluoride) (PVDF) membranes were prepared by isothermal immersion-precipitation of PVDF/N,N-dimethylformamide (DMF) casting dopes in different alcohol baths. The formed membranes can be divided into two groups, based on the morphology and crystal type of the globular particles constituting the membrane matrix. The particles in the first group of membranes appear like a hydrangea flower composed of petal-like crystal lamellae. It was formed when precipitation was carried out in a lower-carbon alcohol bath, e.g. 1- or 2-propanol. On the other hand, when higher alcohol bath such as 1-butanol or 1-octanol bath was used as the coagulant, the formed membranes (group II) comprised compact globules whose surfaces were covered with granular identities of ca. 30 nm dia. XRD and FTIR-ATR analyses of the membranes indicate that group I membranes contain both α- and γ-type crystals, whereas group II membranes contain only γ-type crystals. Transformation of PVDF chains from γ– to α– conformation due to dipole rotation during membrane formation was delineated by 19F NMR spectroscopy. The crystallinities of the membranes were determined both by diffraction peak deconvolution and differential scanning calorimetry. Both methods indicated that the group I membranes had a crystallinity of ca. 66%, which was 5% lower than that of the group II membranes.
關鍵字
語言英文(美國)
ISSN
期刊性質國外
收錄於
產學合作
通訊作者
審稿制度0
國別中華民國
公開徵稿
出版型式,電子版
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