Reyes Guillermo, Ajdary Rubina, Yazdani Maryam R, Rojas Orlando J
Biobased Colloids and Materials, Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, Espoo FI-00076, Finland.
Bioproducts Institute, Department of Chemical & Biological Engineering, Department of Chemistry and Department of Wood Science, The University of British Columbia, 2360 East Mall, Vancouver, BC V6T 1Z3, Canada.
ACS Appl Polym Mater. 2022 Apr 8;4(4):2908-2916. doi: 10.1021/acsapm.2c00177. Epub 2022 Mar 21.
We use dry-jet wet spinning in a coaxial configuration by extruding an aqueous colloidal suspension of oxidized nanocellulose (hydrogel shell) combined with airflow in the core. The coagulation of the hydrogel in a water bath results in hollow filaments (HF) that are drawn continuously at relatively high rates. Small-angle and wide-angle X-ray scattering (SAXS/WAXS) reveals the orientation and order of the cellulose sheath, depending on the applied shear flow and drying method (free-drying and drying under tension). The obtained dry HF show Young's modulus and tensile strength of up to 9 GPa and 66 MPa, respectively. Two types of phase-change materials (PCM), polyethylene glycol (PEG) and paraffin (PA), are used as infills to enable filaments for energy regulation. An increased strain (9%) is observed in the PCM-filled filaments (HF-PEG and HF-PA). The filaments display similar thermal behavior (dynamic scanning calorimetry) compared to the neat infill, PEG, or paraffin, reaching a maximum latent heat capacity of 170 J·g (48-55 °C) and 169 J·g (52-54 °C), respectively. Overall, this study demonstrates the facile and scalable production of two-component core-shell filaments that combine structural integrity, heat storage, and thermoregulation properties.
我们采用同轴配置的干喷湿纺法，通过挤出氧化纳米纤维素的水性胶体悬浮液（水凝胶壳）并在芯部引入气流。水凝胶在水浴中的凝固产生中空长丝（HF），这些长丝以相对较高的速率连续拉伸。小角和广角X射线散射（SAXS/WAXS）揭示了纤维素鞘的取向和有序性，这取决于所施加的剪切流和干燥方法（自由干燥和拉伸干燥）。所获得的干燥HF的杨氏模量和拉伸强度分别高达9 GPa和66 MPa。两种相变材料（PCM），聚乙二醇（PEG）和石蜡（PA），用作填充物以使长丝能够进行能量调节。在填充PCM的长丝（HF-PEG和HF-PA）中观察到应变增加（9%）。与纯填充物PEG或石蜡相比，这些长丝表现出相似的热行为（动态扫描量热法），分别达到最大潜热容量为170 J·g（48-55°C）和169 J·g（52-54°C）。总体而言，本研究展示了结合结构完整性、蓄热和温度调节特性的双组分核壳长丝的简便且可扩展的生产方法。
