Electrospinning Machine | Polyacrylonitrile (PAN) electrospun nanofibrous membrane for removing indoor gaseous phthalates: A health-driven framework for macro-channel adsorption module design and its implications

Phthalates (PAEs), as a class of widely used plasticizers commonly found in various artificial products, possess characteristics such as long release cycles and difficulty in degradation. PAEs not only have endocrine-disrupting effects but may also cause health risks including reproductive system damage, endocrine disorders, childhood asthma, and nervous system developmental disorders. They are typical emerging contaminants and persistent organic pollutants in indoor environments. Currently, the high-efficiency particulate air (HEPA) filters or packed adsorption modules used in traditional air purification equipment have high operational resistance, leading to significant building energy consumption when removing particulate matter and volatile organic compounds (VOCs). This makes it difficult to effectively meet the purification demands for emerging contaminants like PAEs. Therefore, developing a new purification technology capable of efficiently removing PAEs with low resistance is of great importance.

Recently, a research team led by Associate Professor Zhongming Bu from Zhejiang University of Science and Technology published a research paper titled "Polyacrylonitrile (PAN) electrospun nanofibrous membrane for removing indoor gaseous phthalates: A health-driven framework for macro-channel adsorption module design and its implications" in the renowned environmental journal Journal of Hazardous Materials. This study prepared polyacrylonitrile electrospun nanofibrous membranes (PEM) using electrospinning technology and innovatively integrated them into macro-channel air purification modules. By leveraging the excellent adsorption properties of nanofibers, the team achieved efficient removal of gaseous PAEs. The research further established a mass transfer model that accurately describes the PAE adsorption process, systematically revealing the quantitative relationships between key factors—such as material distribution coefficient, membrane thickness, air velocity, and macro-channel geometric parameters—and purification performance. Based on this model, the team proposed a health-benefit-oriented module design and optimization strategy, aiming to achieve anticipated health gains while significantly reducing the system's operational energy consumption.

Figure 1 PEM-based macro-channel purification module and health-oriented module design approach.

Scanning electron microscopy (SEM) images revealed that the prepared PAN nanofibers form a randomly stacked, interpenetrating three-dimensional network structure with an average fiber diameter of approximately 190 nm. Experiments demonstrated that at 25°C, the material's partition coefficients for diethyl phthalate (DEP), diisobutyl phthalate (DiBP), and di-n-butyl phthalate (DnBP) range from 1.12×10^6 to 3.65×10^7, representing a 4 to 30-fold improvement in adsorption performance compared to traditional textile materials. Surface chemical analysis confirmed that the material's chemical structure did not undergo significant changes during the adsorption process, indicating that the adsorption mechanism is primarily physical.

Figure 2 Analysis of PEM morphology and surface chemical characteristics.

Figure 3 Comparison of XPS spectra before and after material adsorption.

Figure 4 Schematic and validation of PAE mass transfer process in macro-channels.

Figure 5 Influence of material characteristics and structural parameters on PEM macro-channel adsorption performance.

Particularly noteworthy is that this study established a health-driven module design methodology. Starting from health requirements, this approach integrates pollutant transport, human exposure, and disease burden assessment models, achieving reverse design and systematic optimization from material properties to module structural parameters. Taking indoor gaseous DnBP purification as an example, with the target of "20% reduction in disease burden," the framework-optimized module (BD-20) significantly outperformed commercial filtration modules in adsorption capacity and service life, reduced operational resistance by over 80%, while maintaining comparable manufacturing costs, demonstrating substantial application potential and promotion value. This research provides new insights and technical support for efficiently removing indoor emerging contaminants with low resistance, holding significant reference value for promoting the development of green, healthy, and low-carbon building environments.

Figure 6 Health benefit-oriented purification module design flowchart.