本研究旨在開發一種具備多氣體吸附能力的綠色高分子薄膜，藉由在高分子結構中引入多重官能性吸附點位，以拓展其在空氣污染控制與氣體感測領域的應用潛力。傳統上，本實驗室所設計之薄膜僅對二氧化碳（CO₂）具備吸附能力，為提升其功能性，本研究導入間苯二胺（m-phenylenediamine）修飾策略，成功引入胺基官能團，賦予材料與其他酸性有害氣體—特別是二氧化硫（SO₂）與甲醛（HCHO）—的專一性吸附能力。
藉由傅立葉轉換紅外光譜（Fourier-transform infrared spectroscopy）驗證修飾後薄膜表面之官能基存在，並保有對CO₂的原始吸附能力。進一步以石英晶體微量天平（Quartz Crystal Microbalance）量測間苯二胺對SO₂與HCHO的吸附能力，顯示其對SO₂具有高度親和性。熱重分析（Thermogravimetric analysis）結果指出，將間苯二胺導入高分子薄膜後，整體氣體吸附效率較原始材料提高約490%。此外，於SO₂吸附過程中觀察到薄膜電阻值明顯下降，從原始的5 MΩ降至0.1 MΩ，顯示氣體分子與胺基交互作用造成導電性顯著變化，驗證其作為氣體感測材料的潛力。
本研究成果展示了透過官能基修飾可有效提升綠色高分子薄膜之多氣體吸附與電性響應能力，並證明此材料具有應用於智慧型氣體感測、工業廢氣處理與環境監控領域的潛力，為永續材料與污染防治技術的整合應用提供嶄新方向。

This study aims to develop an eco-friendly polymer film that exhibits both multi-gas adsorption capability and resistive response characteristics, expanding its potential applications in air pollution control and gas sensing. Polyvinyl alcohol (PVA) was selected as the polymer matrix, while porous silica (SiO₂) served as a high-surface-area support to enhance gas–solid interactions. The film was further functionalized with m-phenylenediamine (MPDA) to introduce amine (–NH₂) groups as active adsorption sites. Through this modification, the film not only retained its original adsorption capacity for carbon dioxide (CO₂) but also gained selective adsorption abilities toward acidic gases such as sulfur dioxide (SO₂) and formaldehyde (HCHO).

Fourier-transform infrared spectroscopy (FTIR) confirmed the successful incorporation of amine functional groups, and the gas adsorption performance was quantitatively evaluated using a quartz crystal microbalance (QCM). The results revealed that MPDA exhibited the highest adsorption capacity for SO₂ (76.5 mg g⁻¹), significantly greater than that for CO₂ (32.1 mg g⁻¹), while the adsorption capacity for HCHO reached 89.3 mg g⁻¹. When MPDA was integrated into the PVA/SiO₂ composite structure, the overall gas adsorption efficiency increased remarkably — by approximately 490% for SO₂ and nearly threefold for HCHO — demonstrating that the high specific surface area effectively promotes the interaction between gas molecules and active sites.

Electrical measurements further showed that, after SO₂ adsorption, the film’s resistance decreased sharply from 5 MΩ to 0.1 MΩ, indicating the formation of ion-conducting pathways (HSO₃⁻, SO₃²⁻) within the polymer network. This pronounced change in electrical resistance verifies the film’s potential for gas-sensing applications, enabling real-time detection of SO₂ concentrations through resistance variation.

In summary, a green, multifunctional polymer composite film with enhanced gas adsorption and resistive response properties was successfully developed. Featuring a simple synthesis process, low cost, and high sensitivity, the proposed material holds strong promise for applications in intelligent gas sensors, industrial flue-gas treatment, and environmental monitoring, highlighting its contribution to sustainable materials science and environmental protection technologies.

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