電紡絲製程可製備達奈米等級的纖維，提升材料的表面積與多孔洞性質，且可使用於多種高分子纖維的連續製程。聚(異丙基丙烯醯胺)，以下簡稱PNIPAM，為一廣受注目的生物可相容性材料，被廣泛運用於生醫領域，因此選用此材料為主體進行電紡絲的相關研究。根據先前研究，以水與二甲基甲醯胺作為溶劑配置PNIPAM溶液時，隨溶劑組成的不同，溶液具有LCST或UCST的特性。為更了解PNIPAM溶液之相行為，使用流變儀、小角光散射等技術研究不同組成溶液，並進行電紡，分析電紡纖維形態與液柱變化的情形。

在相行為的結果中，10 wt% PNIPAM water/DMF(25/75)溶液以不同降溫速率的光穿透度變化，所得Tb,cp為24.6 oC。透過小角光散射觀察溶液相分離情形，隨溫度變化的過程中產生兩散射峰，推測有二次相分離情形。PNIPAM水溶液以流變儀量測流變性質，經過計算獲得不同濃度的臨界凝膠生成溫度。此外，小角光散射的結果顯示凝膠結構在q=2 um-1以下有散射強度的貢獻。

電紡絲部分，以固定參數對water/DMF組成為10/90、25/75的10 wt% PNIPAM溶液進行電紡，當water/DMF=10/90時，cone高度與液柱長度皆較大，且液柱直徑隨z變化的程度較高，所收集到的纖維直徑較大。變溫電紡10 wt% PNIPAM water/DMF(25/75)溶液，所得纖維直徑隨溫度下降而上升，並隨溫度下降出現攤平在收集板上的情形。最後，透過雷射打擊玻璃棒以模擬電紡過程中Taylor cone區域散射圖案的變化。

According to previous research, poly(N-isopropyl acrylamide)(PNIPAM) solutions in water/dimethylformamide(DMF) show different phase behaviors, depending on the composition of solvents. PNIPAM aqueous solution has a lower critical solution temperature near the room temperature. As the ratio of DMF increases, the solution changes to have an upper critical solution temperature. In order to obtain uniform fibers, solutions properties and phase separation temperatures were measured by light scattering and rheometer. Then, temparatures of the environment and solution were controlled to realize the effect of phase separation on electrospinning.

Under suitable parameters, electrospinning with different compositions and temperatures can remain stable. Jet was observed by laser light scattering during electrospinning, and the morphologies of as-spun fibers were identified by SEM to find evidence that phase separation happened during electrospinning.

A glass conical rod was used to simulate the apex region of the Taylor cone during electrospinning. The refraction pattern and the edge scattering pattern are similar to the case of electrospinning. More relative physical significance could be investigated in the future.

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