Effect of ion doping on microwave absorbing properties of sodium alginate/SiO2 aerogels
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摘要: 随着电磁污染的加剧,吸波材料引起了研究者的关注,气凝胶具有轻质、多孔的特性赋予其成为理想吸波材料的潜质。以聚乙烯醇(PVA)和正硅酸乙酯(TEOS)为原料,静电纺丝制得PVA/SiO2纳米纤维,高温碳化得到柔性SiO2纳米纤维;将柔性SiO2纳米纤维均化在海藻酸钠(SA)溶液中,冷冻干燥得到SA/SiO2气凝胶;分别引入铝硼硅(AlBSi)、FeCl3作为掺杂剂得到SA/SiO2/AlBSi、SA/SiO2/FeCl3气凝胶,对比分析3种气凝胶吸波性能。结果表明:SA/SiO2经FeCl3掺杂后,SiO2纳米纤维表面有小晶粒存在,这种块状颗粒结构能够产生多重反射和散射、界面极化,提高了气凝胶的介电损耗性能。并且加入FeCl3后,气凝胶的磁损耗虚部增大,提高了气凝胶的磁损耗性能,使其整体吸波性能提高,当厚度为3 mm时,其最大的吸收峰值–23.85 dB在14.42 GHz处达到,具有1.3 GHz (13.82~15.12 GHz)的有效吸收带宽,是一种质轻、吸波性能良好的材料。Abstract: With the intensification of electromagnetic pollution, absorbing materials have attracted the attention of researchers, and airgel has the potential to become an ideal absorbing material due to its light weight and porous characteristics. PVA/SiO2 nanofibers were prepared by electrospinning from polyvinyl alcohol (PVA) and ethyl orthosilicate (TEOS), the flexible SiO2 nanofibers were homogenized in sodium alginate (SA) solution and freezedried to obtain SA/SiO2 aerogels. SA/SiO2/AlBSi and SA/SiO2/FeCl3 aerogels were prepared by introducing AlBSi and FeCl3 as dopants, respectively. Microwave absorbing properties of three kinds of aerogels were analyzed. The results show that there are small particles on the surface of SiO2 nanofibers, which are the SA/SiO2 aerogel doped by FeCl3. This granular structure produces multiple reflection and scattering, interface polarization, which improves the dielectric loss performance of aerogels. After adding FeCl3, the imaginary part of the magnetic loss of the aerogel increases, which improves the magnetic loss performance of the aerogel. Thus, the overall wave absorption performance of aerogel is improved. When the thickness is 3 mm, its maximum absorption peak is –23.85 dB, reaching 14.42 GHz. It has an effective absorption bandwidth of 1.3 GHz (13.82-15.12 GHz). It is a light material with good wave absorption performance.
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Key words:
- SiO2 aerogel /
- doping /
- dielectric loss /
- multiple relaxation /
- wave absorbing performance
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图 4 SA/SiO2、SA/SiO2/AlBSi、SA/SiO2/FeCl3气凝胶的介电常数实部ε' (a)、介电常数虚部ε'' (b)、介电损耗正切角ε''/ε' (c)及其磁导率实部μ' (d)、磁导率虚部μ'' (e)、磁损耗正切角μ''/μ' (f)随频率的变化曲线
Figure 4. Real part of dielectric constant ε' (a), imaginary part of dielectric constant ε'' (b), dielectric loss tangent angle ε''/ε' (c) and change curves of real part of permeability μ' (d), imaginary part of the permeability μ'' (e), magnetic loss tangent angle μ''/μ' (f) with frequency for SA/SiO2, SA/SiO2/AlBSi, SA/SiO2/FeCl3 aerogel
图 6 SA/SiO2、SA/SiO2/AlBSi、SA/SiO2/FeCl3气凝胶的衰减系数(a)和SA/SiO2/FeCl3气凝胶阻抗匹配随频率的变化曲线图(b)
α—Attenuation coefficient; Ζ—Impedance matching value
Figure 6. Curves of attenuation coefficient of SA/SiO2, SA/SiO2/AlBSi, SA/SiO2/FeCl3 aerogel (a) and impedance matching of SA/SiO2/FeCl3 aerogel versus frequency (b)
表 1 几种陶瓷基材料的吸波性能对比
Table 1. Comparison of wave absorption properties of several ceramic-based materials
Absorbent material Thickness/mm RL, min/dB Frequency/GHz Effective absorption
frequency band/GHzMaterial content/wt% Ref. SiC 2.4 18.58 15.44 4.56 30 [13] SiCN 3.0 54.35 9.62 4.16 30 [11] SiC/Cf 1.8 40.66 8.31 1.11 30 [23] Fe3O4/SiO2 5.0 37.15 16.90 1.94 30 [24] FeSiAl/SiO2 2.0 17.90 14.83 2.90 37.5 [25] SA/SiO2/FeCl3 3.0 24.23 14.47 1.30 7 This work Note: RL, min—Minimum reflectivity loss. -
[1] DOU L Y, ZHANG X X, SHAN H R, et al. Interweaved cellular structured ceramic nanofibrous aerogels with superior bendability and compressibility[J]. Advanced Functional Materials,2020,30(49):2005928. doi: 10.1002/adfm.202005928 [2] ABDALLA I, SALIM A, ZHU M M, et al. Light and flexible composite nanofibrous membranes for high-efficiency electromagnetic absorption in a broad frequency[J]. ACS Applied Materials & Interfaces,2018,10(51):44561-44569. [3] LI C B, LI Y J, ZHAO Q, et al. Electromagnetic interference shielding of graphene aerogel with layered microstructure fabricated via mechanical compression[J]. ACS Applied Materials & Interfaces,2020,12(27):30686-30694. [4] 吕通, 张辰威, 刘甲, 等. 吸波超材料研究进展[J]. 复合材料学报, 2021, 38(1):25-35. doi: 10.13801/j.cnki.fhclxb.20200921.004LYU Tong, ZHANG Chenwei, LIU Jia, et al. Research progress in metamaterial absorber[J]. Acta Materiae Compositae Sinica,2021,38(1):25-35(in Chinese). doi: 10.13801/j.cnki.fhclxb.20200921.004 [5] REN J Q, LYU Y T, LIU Z G, et al. Microwave absorption performance evaluation of carbonized derivatives of Fe3O4@MOF-74 with controllable morphologies[J]. ACS Applied Electronic Materials,2022,4(11):5221-5233. doi: 10.1021/acsaelm.2c00900 [6] LIU C, WU P F, CHEN S H, et al. Kill two birds with one stone: Multifunctional porous SiOC-Fe2O3 composite for Li ion energy conversion and electromagnetic wave absorption[J]. ACS Applied Electronic Materials,2022,4(12):6177-6188. doi: 10.1021/acsaelm.2c01305 [7] WANG P, LI Z C, CHENG L F, et al. SiC/rGO core-shell nanowire as a lightweight, highly efficient gigahertz electromagnetic wave absorber[J]. ACS Applied Electronic Materials,2020,2(2):473-482. doi: 10.1021/acsaelm.9b00721 [8] HAN M K, YIN X W, HANTANASIRISAKUL K, et al. Anisotropic MXene aerogels with a mechanically tunable ratio of electromagnetic wave reflection to absorption[J]. Advanced Optical Materials,2019,7(10):1900267. doi: 10.1002/adom.201900267 [9] SU L, LI M Z, WANG H J, et al. Resilient Si3N4 nanobelt aerogel as fire-resistant and electromagnetic wave-transparent thermal insulator[J]. ACS Applied Materials & Interfaces,2019,11(17):15795-15803. [10] SI Y, FU Q X, WANG X Q, et al. Superelastic and superhydrophobic nanofiber-assembled cellular aerogels for effective separation of oil/water emulsions[J]. ACS Nano,2015,9(4):3791-3799. doi: 10.1021/nn506633b [11] 梁军芳. SiCN先驱体陶瓷气凝胶复合材料的构筑及其吸波性能研究[D]. 郑州: 郑州大学, 2020.LIANG Junfang. Construction and electromagnetic wave absorption performance of SiCN precursor ceramic aerogel composites[D]. Zhengzhou: Zhengzhou University, 2020. [12] 王立杰. 石墨烯复合气凝胶的制备及电磁性能研究[D]. 郑州: 郑州航空工业管理学院, 2020.WANG Lijie. Synthesis of graphene composite aerogels and their electromagnetic wave absorption properties study[D]. Zhengzhou: Zhengzhou University of aeronautics, 2020(in Chinese). [13] 白力文. SiC气凝胶吸波材料的制备及性能研究[D]. 哈尔滨: 哈尔滨工业大学, 2020.BAI Liwen. Prepartion and properties of SiC aerogels electromagnetic wave absorbing materials[D]. Harbin: Harbin Institute of Technology, 2020(in Chinese). [14] XIE A M, WU F, XU Z H, et al. In situ preparation of ultralight three-dimensional polypyrrole/nano SiO2 composite aerogels with enhanced electromagnetic absorption[J]. Composites Science and Technology,2015,117:32-38. doi: 10.1016/j.compscitech.2015.05.010 [15] AN Z M, YE C S, ZHANG R B, et al. Multifunctional C/SiO2/SiC-based aerogels and composites for thermal insulators and electromagnetic interference shielding[J]. Journal of Sol-Gel Science and Technology,2019,89(3):623-633. doi: 10.1007/s10971-019-04916-5 [16] MARTINEZ J R, RUIZ F, VOROBIEV Y V , et al. Infrared spectroscopy analysis of the local atomic structure in silica prepared by sol-gel[J]. Journal of Chemical Physics, 1988, 109(17): 7511-7514. [17] SI Y, WANG L H, WANG X Q, et al. Ultrahigh-water-content, superelastic, and shape-memory nanofiber-assembled hydrogels exhibiting pressure-responsive conductivity[J]. Advanced Materials,2017,29(24):1700339. [18] 李俊, 齐鲁, 李慧皓. FeCl3/共轭聚席夫碱复合材料及介电性能分析[J]. 无机化学学报, 2016, 32(1):96-102.LI Jun, QI Lu, LI Huihao. Synthesis and dielectric properties of FeCl3/conjugated ploy schiff base composite[J]. Chinese Journal of Inorganic Chemistry,2016,32(1):96-102(in Chinese). [19] SONG Z M, LIU X F, SUN X, et al. Alginate-templated synthesis of CoFe/carbon fiber composite and the effect of hierarchically porous structure on electromagnetic wave absorption performance[J]. Carbon,2019,151:36-45. doi: 10.1016/j.carbon.2019.05.025 [20] LIU Y, FENG Y R, GONG H Y, et al. Microwave absorbing performance of polymer-derived SiCN(Ni) ceramics prepared from different nickel sources[J]. Journal of Alloys and Compounds,2018,749:620-627. doi: 10.1016/j.jallcom.2018.03.346 [21] ADEBAYO L L, SOLEIMANI H, YAHYA N, et al. Recent advances in the development of Fe3O4-based microwave absorbing materials[J]. Ceramics International,2020,46(2):1249-1268. doi: 10.1016/j.ceramint.2019.09.209 [22] 武志红, 李妤婕, 张聪, 等. 竹炭/SiC复合材料结构及其吸波性能[J]. 硅酸盐学报, 2018, 46(1):150-155. doi: 10.14062/j.issn.0454-5648.2018.01.20WU Zhihong, LI Yujie, ZHANG Cong, et al. Structure and microwave absorption properties of bamboo charcoal/SiC composites[J]. Journal of the Chinese Ceramic Society,2018,46(1):150-155(in Chinese). doi: 10.14062/j.issn.0454-5648.2018.01.20 [23] 武志红, 邓悦, 蒙真真, 等. 含SiC阵列改性涂层的新型 SiC/Cf复合材料吸波性能研究[J]. 无机材料学报, 2021, 36(3):306-312. doi: 10.15541/jim20200364WU Zhihong, DENG Yue, MENG Zhenzhen, et al. Microwave absorbing properties of novel SiC/Cf compo-sites containing SiC array modified coating[J]. Journal of Inorganic Materials,2021,36(3):306-312(in Chinese). doi: 10.15541/jim20200364 [24] 马勖凯. 点击反应制备碳纳米管/金属氧化物/二氧化硅复合材料及吸波性能研究[D]. 淮南: 安徽理工大学, 2020.MA Xukai. Click reaction to prepare carbon nanotube/metal oxide/silica composite material and its microwave absorbing properties[D]. Huainan: Anhui University of Science and Technology, 2020(in Chinese). [25] 高少华. 片状铁硅铝/二氧化硅复合涂层的电磁波吸收性能研究[D]. 大连, 大连理工大学, 2018.GAO Shaohua. Study on the microwave absorption performance of flaky FeSiAl/SiO2 composite coatings[D]. Dalian: Dalian University of Technology, 2018(in Chinese). [26] ZHANG X F, CHEN Z Y, FENG Y, et al. Low-temperature transformation of C/SiO2 nanocomposites to β-SiC with high surface area[J]. ACS Sustainable Chemistry & Engi-neering,2018,6(1):1068-1073. [27] LAN D, GAO Z G, ZHAO Z H, et al. Application progress of conductive conjugated polymers in electromagnetic wave absorbing composites[J]. Composites Communications,2021,26:100767. doi: 10.1016/j.coco.2021.100767 [28] JI H M, LI J H, ZHANG J J, et al. Remarkable microwave absorption performance of ultralight graphene-polyethylene glycol composite aerogels with a very low loading ratio of graphene[J]. Composites Part A: Applied Science and Manufacturing,2019,123:158-169. doi: 10.1016/j.compositesa.2019.05.012 [29] HUANG Y F, XIE Y L, ZHAO J A, et al. Variety of ZIF-8/MXene-based lightweight microwave-absorbing materials: Preparation and performances of ZnO/MXene nanocomposites[J]. Journal of Physical Chemistry C,2022,126(32):13847-13853. doi: 10.1021/acs.jpcc.2c04026 [30] SUN Y C, CUI W Y, LI J L, et al. In-situ growth strategy to fabrication of MWCNTs/Fe3O4 with controllable interface polarization intensity and wide band electromagnetic absorption performance[J]. Journal of Alloys and Compounds,2019,770:67-75. doi: 10.1016/j.jallcom.2018.08.106 [31] WEN B, CAO M S, HOU Z L, et al. Temperature dependent microwave attenuation behavior for carbon-nanotube/silica composites[J]. Carbon,2013,65:124-139. doi: 10.1016/j.carbon.2013.07.110 [32] KONG L, YIN X W, ZHANG Y J, et al. Electromagnetic wave absorption properties of reduced graphene oxide modified by maghemite colloidal nanoparticle clusters[J]. Journal of Physical Chemistry C,2013,117(38):19701-19711. doi: 10.1021/jp4058498 [33] HAN M K, YIN X W, HOU Z X, et al. Flexible and thermostable graphene/SiC nanowire foam composites with tunable electromagnetic wave absorption properties[J]. ACS Applied Materials & Interfaces,2017,9(13):11803-11810. [34] 叶喜葱, 欧阳宾, 杨超, 等. 石墨烯-羰基铁粉线材的制备及其吸波性能分析[J]. 复合材料学报, 2022, 39(7):3292-3302. doi: 10.13801/j.cnki.fhclxb.20210819.008YE Xicong, OUYANG Bin, YANG Chao, et al. Preparation of graphene-carbonyl iron powder wire and analysis of its wave absorption performance[J]. Acta Materiae Compositae Sinica,2022,39(7):3292-3302(in Chinese). doi: 10.13801/j.cnki.fhclxb.20210819.008 [35] HU P T, DONG S, LI X T, et al. A low-cost strategy to synthesize MnO nanorods anchored on 3D biomass-derived carbon with superior microwave absorption properties[J]. Journal of Materials Chemistry C,2019,7(30):9219-9228. doi: 10.1039/C9TC02182E [36] QIU X, WANG L X, ZHU H L, et al. Lightweight and efficient microwave absorbing materials based on walnut shell-derived nano-porous carbon[J]. Nanoscale,2017,9(22):7408-7418. doi: 10.1039/C7NR02628E [37] LIU L L, ZHANG S, YAN F, et al. Three-dimensional hierarchical MoS2 nanosheets/ultralong N-doped carbon nanotubes as high-performance electromagnetic wave absorbing material[J]. ACS Applied Materials & Interfaces,2018,10(16):14108-14115. [38] ZHAO H Q, CHENG Y, LYU H L, et al. Achieving sustainable ultralight electromagnetic absorber from flour by turning surface morphology of nanoporous carbon[J]. ACS Sustainable Chemistry & Engineering,2018,6(11):15850-15857.