我們提出了一套氣相電場分離方法，來鑑定奈米氧化石墨烯(Graphene oxide)、孔性金屬-有機配位聚合物(Metal-organic frameworks)和陶瓷奈米材料(Ceramic nanoparticle)膠體懸浮液。在我們的研究中，電噴灑式氣相奈米粒徑分析儀(electrospray-differential mobility analysis，ES-DMA)除了能用來取得膠體奈米材料的數量濃度與物理尺寸的資訊外，其亦能用於分析粒子的解體(de-aggregation)與解聚(dis-assembly)現象之可逆過程、及配體-奈米粒子間交互作用對其膠體穩定性的影響。同時，TEM與SEM亦被我們用於觀察這些非球型奈米粒子的影像資訊，並對ES-DMA的結果予以佐證。結果顯示解聚、解體與聚集(aggregation)現象的發生與奈米材料的表面電位(zeta potential)和等電點(isoelectric point)、所使用配體的酸解離常數(pKa)和環境的酸鹼值有強烈的關聯性。透過調整這些影響因素，我們就能控制其粒徑大小與分佈區間。因此，這個方法能成功地對這些非球型奈米粒子進行定量分析，並期許它能提供液相配方化學合成和氣溶膠科學的研究一個前進未來的方向與動力。

We report a state-of-the-art gas-phase electrophoresis method for the characterization of nanosheet graphene oxide, metal-organic frameworks (MOF), and ceramic nanoparticle aggregates in the form of nanomaterial suspension. In this study, electrospray-differential mobility analysis (ES-DMA) is used to quantify number concentration and dimensional properties, analyze the reversibly dis-assembly and de-aggregation processes and ligand-nanoparticle interactions to colloidal stability of nanomaterial. Transmission electron microscopy and scanning electron microscopy are employed orthogonally to provide complementary data and imagery of nanomaterial. Results show that the equivalent mobility sizes, size distributions, and number concentrations of these functional nanomaterials are able to be successfully measured by ES-DMA. Aggregation, de-aggregation, and dis-assembly processes of nanomaterial colloids are strongly correlated to the zeta potential and isoelectric point of nanomaterials, dissociation constant of the functional ligands, and the pH in the environment, providing an effective route to control the primary size as well as the size homogeneity. This prototype study demonstrates a proof of concept of using ES-DMA to quantitatively characterize nonspherical functional nanomaterials. The results provide beneficial guidelines for the aqueous formulation chemistry of nanomaterial-based platforms (e.g., metalation in MOF) and the subsequent electrospray-assisted device integration.

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