Airborne nanoplastics: surface chemistry and cloud-crystallisation properties

空气中的纳米塑料：表面化学和云结晶特性

• 批准号: 2592772
• 金额: --
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2592772
• 关键词: Airborne; nanoplastics; surface; chemistry; cloud

The amount of micro and sub-micro-sized plastic particles polluting the environment is, unfortunately, increasing due to human activity. It has been shown that microplastics have an adverse effect on the environment, but little is known about their influence on the formation of ice in clouds (which alters the radiative properties of the Earth). Moreover, our theoretical understanding of the phenomenon of ice formation is fairly poor. As a result, models cannot be used accurately to predict whether a substrate will promote the formation of an ice nucleus within a body of liquid water. Therefore, experimental investigations are needed to assess whether a plastic species will promote the formation of ice crystals in clouds. For this purpose, microplastics are synthesized using cryogenic ball milling and separated in size by sieving. Their sizes and surface functionalities were investigated using characterization techniques such as XPS, optical microscopy, and IR spectroscopy. The ice nucleating properties of the laboratory-made microplastics are investigated by performing droplet freezing experiments with suspensions of the plastic samples in ultrapure water. For this, the IceBox, a novel open droplet system, was used to cool suspension droplets at a constant rate in an atmosphere with controlled humidity. Depending on the plastic's chemical and physical characteristics, the micro and nano plastics could have a notable effect on the temperature of freezing of the droplets. This research will be of importance to both the field of atmospheric science and ice physics.

不幸的是，由于人类活动，污染环境的微米和亚微米塑料颗粒的数量正在增加。研究表明，微塑料对环境有不利影响，但人们对它们对云中冰的形成（改变地球的辐射特性）的影响知之甚少。此外，我们对冰形成现象的理论理解相当差。因此，模型不能准确地用于预测基质是否会促进液态水体内冰核的形成。因此，需要实验研究来评估塑料物种是否会促进云中冰晶的形成。为此目的，使用低温球磨合成微塑料，并通过筛分分离尺寸。它们的大小和表面功能进行了研究，使用表征技术，如XPS，光学显微镜，红外光谱。通过对实验室制备的微塑料样品在超纯水中的悬浮液进行液滴冻结实验，研究了微塑料的冰成核特性。为此，IceBox，一种新型的开放式液滴系统，用于在具有受控湿度的大气中以恒定速率冷却悬浮液滴。根据塑料的化学和物理特性，微米和纳米塑料可能对液滴的冻结温度产生显着影响。这一研究对大气科学和冰物理学都具有重要意义。