Cellulose, Nanocellulose, and Antimicrobial Materials for the Manufacture of Disposable Face Masks: A Review

Cellulose is among the most promising renewable and biodegradable materials that can help meet the challenge of replacing synthetic fibers currently used in disposable N95 respirators and medical face masks. Cellulose also offers key functionalities that can be valued in filtration applications using approaches such as nanofiltration, membrane technologies, and composite structures, either through the use of nanocellulose or the design of functional composite filters. This paper presents a review of the structures and compositions of N95 respirators and medical face masks, their properties, and regulatory standards. It also reviews the use of cellulose and nanocellulose materials for mask manufacturing, along with other (nano)materials and composites that can add antimicrobial functionality to the material. A discussion of the most recent technologies providing antimicrobial properties to protective masks (by the introduction of natural bioactive compounds, metal-containing materials, metal-organic frameworks, inorganic salts, synthetic polymers, and carbon-based 2D nanomaterials) is presented. This review demonstrates that cellulose can be a solution for producing biodegradable masks from local resources in response to the high demand due to the COVID-19 pandemic and for producing antimicrobial filters to provide greater protection to the wearer and the environment, reducing crosscontamination risks during use and handling, and environmental concerns regarding disposal after use.

纤维素是最有前景的可再生和可生物降解材料之一，它有助于应对替代目前一次性N95口罩和医用口罩中使用的合成纤维这一挑战。纤维素还具备关键功能，在诸如纳滤、膜技术和复合结构等过滤应用中具有价值，无论是通过使用纳米纤维素还是设计功能性复合过滤器。本文综述了N95口罩和医用口罩的结构、组成、性能以及监管标准。还综述了纤维素和纳米纤维素材料在口罩制造中的应用，以及其他可为材料增添抗菌功能的（纳米）材料和复合材料。讨论了为防护口罩提供抗菌性能的最新技术（通过引入天然生物活性化合物、含金属材料、金属 - 有机框架、无机盐、合成聚合物和碳基二维纳米材料）。本综述表明，纤维素可以作为一种解决方案，利用当地资源生产可生物降解的口罩，以应对新冠疫情带来的高需求，并且用于生产抗菌过滤器，为佩戴者和环境提供更好的保护，降低使用和处理过程中的交叉污染风险，以及使用后处理相关的环境问题。