高强韧透明细菌纤维素薄膜

High Strength and Toughness Transparent Bacterial Cellulose Film

细菌纤维素(Bacterial cellulose,BC)是一种可生物降解的天然生物大分子,其纳米网状结构和高结晶度使BC具有较高的机械强度,但较差的韧性和半透明性限制了其应用。通过以氯化胆碱/尿素(ChCl/urea)为增塑剂,采用简单浸渍法制备了BC/ChCl/urea复合膜。其中,ChCl/urea通过破坏纤维素分子间氢键并在增塑剂与纤维素之间形成新的氢键,有效的将BC的断裂伸长率从2.82%提高到28.85%,同时保持186 MPa的抗拉强度。断裂能也从2.68 MJ/m^(3)增加到43.52 MJ/m^(3)。BC/ChCl/urea复合膜具有良好的柔韧性和耐折叠性,透明度可达92.4%。薄膜的透明度和柔软度在30天后保持不变。用BC/ChCl/urea复合薄膜作为近场通信(NFC)的基底材料时在弯曲和拉伸下仍能有效地传输信息,预示其在可穿戴设备和电子设备基底材料具有潜在应用前景。

Bacterial cellulose(BC)is a biodegradable natural biological macromolecule,which has high mechanical strength due to its nano-network structure and high crystallinity,but its poor toughness and translucency limit its application.Here,by adding choline chloride/urea(ChCl/urea)as plasticizer,we prepared BC/ChCl/urea composite film by a simple impregnation method.It is indicated that ChCl/urea can effectively improve the elongation of BC by breaking the intermolecular hydrogen bond of cellulose and forming a new hydrogen bond between plasticizer and cellulose,which increases from 2.82%to 28.85%,while maintaining a high strength of 186 MPa.The fracture energy also increases from 2.68 MJ/m^(3) to 43.52 MJ/m^(3).BC/ChCl/urea composite film has good flexibility and folding resistance,and its transparency is up to 92.4%.The transparency and softness of the film remained unchanged after 30 days of storage.When used as the basic material of near-field communication(NFC),the BC/ChCl/urea composite film shows effective information transmission even under bending and stretching,indicating the potential to be used as substrate materials for wearable and electronic devices.