Saberi Sahel, Abdeali Golnoosh, Bahramian Ahmad Reza
Polymer Engineering Department, Faculty of Chemical Engineering, Tarbiat Modares University P. O. Box 14115-143 Tehran Iran
PRISM Research Institute, Technological University of the Shannon University Road N37HD68 Athlone Ireland
RSC Adv. 2025 Apr 2;15(13):10049-10073. doi: 10.1039/d4ra07932a. eCollection 2025 Mar 28.
Organic phase change materials (PCMs) are promising for sustainable energy due to their high storage capacity, broad temperature control, and minimal volume change during phase transitions. However, their application is limited by low thermal conductivity and high leakage caused by volume instability. To address these issues, a shape-stabilizing approach using a nature-based and porous matrix of cellulose from recyclable resources, is proposed. In this study, a cellulose hydrogel-based composite was used as a support for encapsulating polyethylene glycol (PEG 2000) PCM, creating a phase change composite (PCC). Cellulose was extracted from waste newspaper (WP) through alkaline and peroxide treatments, achieving 16.5% efficiency and 78% purity. The cellulose was then used to synthesize different three-dimensional (3D) hydrogel networks with citric acid (CA) as the cross-linking agent. Carbon monofilaments (CFs) were incorporated into the hydrogels to enhance stability, reduce leakage, and improve thermal properties. The thermophysical and morphological characterization of the prepared system revealed that cellulose-based hydrogels were formed through esterification between cellulose hydroxyl groups and CA carboxyl groups. The leakage rate of the (cell-4/CF/PEG) PCC was measured as 4.25 wt% after 5 heating-cooling cycles. The latent heat of melting was similar to pure PEG 2000, with an energy storage capacity increase of 25%. Furthermore, the addition of CFs improved thermal conductivity () by 80% and achieved an enthalpy efficiency of 90%. The thermal diffusivity (), specific heat capacity ( ), and effective thermal conductivity ( ) of the (cell-4/CF/PEG) PCC were recorded as 8.2 × 10 m s, 5400 J kg °C, and 0.027 W m °C, respectively.
有机相变材料（PCM）因其高储能容量、宽温度控制范围以及相变过程中体积变化最小等特性，在可持续能源领域具有广阔前景。然而，其应用受到低导热率以及由体积不稳定性导致的高泄漏率的限制。为解决这些问题，本文提出了一种利用可回收资源中基于天然且多孔的纤维素基质的形状稳定化方法。在本研究中，一种基于纤维素水凝胶的复合材料被用作封装聚乙二醇（PEG 2000）相变材料的载体，从而制备出相变复合材料（PCC）。通过碱处理和过氧化物处理从废报纸（WP）中提取纤维素，提取效率达到16.5%，纯度为78%。然后，以柠檬酸（CA）作为交联剂，用该纤维素合成不同的三维（3D）水凝胶网络。将碳单丝（CFs）加入水凝胶中以增强稳定性、减少泄漏并改善热性能。对所制备体系的热物理和形态表征表明，基于纤维素的水凝胶是通过纤维素羟基与CA羧基之间的酯化反应形成的。经过5次加热 - 冷却循环后，（cell - 4/CF/PEG）PCC的泄漏率测定为4.25 wt%。其熔化潜热与纯PEG 2000相似，储能容量增加了25%。此外，CFs的加入使热导率（）提高了80%，焓效率达到90%。（cell - 4/CF/PEG）PCC的热扩散率（）、比热容（）和有效热导率（）分别记录为8.2×10 m s、5400 J kg °C和0.027 W m °C。
