無規則共聚物表面改質對嵌段式共聚物及其超分子薄膜結構之影響

Cross-Linked Random Copolymer Mats for Controlling the Orientation of Block Copolymers and their Supramolecules in Thin Films

林心冠(Xin-Guan Lin)

指導教授 ： 童世煌

國立臺灣大學/工學院/高分子科學與工程學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.01936

摘要

本實驗研究以無規則共聚物表面改質後對於嵌段式共聚物PS-b-P4VP與超分子共聚物PS-b-P4VP(PDP)x薄膜微相分離之影響，以 BPO / TEMPO 所形成的氮氧自由基的方式合成無規則共聚物P(S-r-BCB-r-4VP)，將此無規則共聚物熱交聯在矽晶圓表面上形成一層網狀交聯的薄膜，探討嵌段式共聚物以及超分子共聚物薄膜在改質後的基板上之變化性。
在嵌段式共聚物系統下，我們使用層狀與柱狀兩種不同形態之嵌段式共聚物，以不同組成比例之無規則共聚物表面改質後，發現在未改質前 PS(20,000)-b-P4VP(17,000) 原本平躺於基板的層狀結構，在特定組成比例下可轉變成垂直於基板的層狀結構，且伴隨著島與洞的結構 (islands and holes)。在另一系統下，在未改質前PS(48,000)-b-P4VP(20,300) 原本平躺於基板的圓柱，在表面改質後可轉變為垂直於基板的圓柱。表面改質確是能夠改變嵌段式共聚物薄膜結構之方向性，因此，我們對於接枝上小分子之超分子共聚物薄膜在改質後的基板上之變化性也做更深入研究。
在超分子共聚物PS(20,000)-b-P4VP(17,000)(PDP)x 薄膜系統下，將基板表面改質為一層P4VP網狀交聯的共聚物薄膜，可觀察到其大結構的轉變；在未改質前x = 0.5、1.0為平躺與垂直於基板的圓柱，在P4VP改質後其形態分別轉變為六角堆積之對穿層結構 (Hexagonally Perforated Layer，HPL) 以及平躺於基板的圓柱。另一方面，我們將表面以PS改質後，則觀察到在高接枝比例下 (x=0.8-1.5) ，小分子在薄膜底層排列的方向由垂直於基板方向轉變為平行於基板方向的層狀結構，然而大結構之形態與未改質前相似。

關鍵字

嵌段式共聚物 ； 超分子 ； 表面改質 ； 無規則共聚物 ； 薄膜 ； TEMPO

並列摘要

A series of benzocyclobutene-functionalized random copolymers of styrene and 4-vinylpyridine were synthesized by nitroxide-mediated controlled radical polymerization with BPO and TEMPO.Our research was to use these random copolymers [P(S-r-BCBr-4VP)] to control the orientation of microdomains in thin films of poly(styrene-b-4-vinylpyridine) block copolymer (PS-b-P4VP) and their supramolecules based on an ultrathin cross-linkable film.
We used PS(20,000)-b-P4VP(17,000) and PS(48,000)-b-P4VP(20,300) two kinds of block copolymers which possess lamella and cylinder in bulk morphology, respectively. In particular compositions of random copolymer,we found that the parallel orientation of lamella is switched to be perpendicular in PS(20,000)-b-P4VP(17,000) thin film with the formation of islands and holes.In another system,the parallel orientation of cylinders is switched to be perpendicular in PS(48,000)-b-P4VP(20,300) thin film.These results revealed that the modifid substrate can successfully control the orientation of microdomains in thin films.Therefore,we investigated the effects of modifid substrate on supramolecular thin films.
On the P4VP-modified substrate, the surface morphology is dramatically changed.We found that the parallel and perpendicular orientation of cylinder is switched to be hexagonally perforated layer (HPL) and parallel orientation of cylinder,respectively.On the PS-modified substrate,we found that at the higher grafting density of PDP onto P4VP chains ,i.e x=0.8-1.5,the comb block lamellar orientation is switched to be perpendicular orientation of lamellae through the underlying thin film, nevertheless,the orientation of the large-scale cylinders were maintained.

並列關鍵字

TEMPO ； block copolymer ； supramolecule ； thin film ； random copolymer ； substrate modification

參考文獻

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