氧化石墨烯负载无纺布复合膜的制备及光热转换性能

Preparation of graphene oxide supported non-woven fabric composite membrane and its photothermal conversion performance

氧化石墨烯(GO)是一种性能良好的光热转换材料,广泛用于海水淡化、光电转换和太阳能利用等领域。为了测试GO负载无纺布膜(GO膜)和聚乙烯醇-氧化石墨烯无纺布复合膜(PVA-GO复合膜)的光热水蒸发特性,通过改进Hummers方法制备GO,选取了纤维素和聚酯类型的无纺布,通过浸泡-超声法制得GO膜和PVA-GO复合膜。运用紫外-可见-近红外光谱仪分析了GO膜和PVA-GO复合膜的吸光性能,并通过电子天平测量GO膜和PVA-GO复合膜的蒸发水量。由于PVA具有亲水性,能增大膜的吸水性,因而PVA加入会使蒸发水量增大。通过SEM分析GO膜和PVA-GO复合膜表面特征,发现无添加PVA的GO膜是纤维丝状结构,且纤维清晰可见。加入PVA后,纤维被PVA包裹,说明膜对光的吸收能力增强。当加入6wt%PVA时,无纺布纤维被PVA完全包裹。当用氙灯对两种膜进行水蒸发实验时,GO膜的蒸发速率达到了1.67 kg/(m^(2)·h),PVA-GO复合膜的蒸发速率达到了1.85 kg/(m^(2)·h)。此外,GO膜中出现GO层状结构,在紫外-可见-近红外光谱分析中表现出较好的吸光能力,在光热蒸发实验中表现出较好的光热转换能力。PVA-GO复合膜在PVA质量浓度为4wt%时有较好的光热转换性能和吸光性。

Graphene oxide(GO)is a photothermal conversion material with good performance,which is widely used in seawater desalination,photoelectric conversion and solar energy utilization.In order to test the photothermal evaporation characteristics of GO supported non-woven fabric film(GO film)and polyvinyl alcohol-graphene oxide non-woven fabric composite film(PVA-GO composite film),GO was prepared by an improved Hummers method,and non-woven fabrics of cellulose and polyester were selected,and GO membranes and PVA-GO composite membranes were prepared by immersion-ultrasonic method.Ultraviolet-visible-near infrared spectrometer was used to analyze the light absorption properties of GO film and PVA-GO composite film,and the amount of evaporated water of GO film and PVA-GO composite film was measured by electronic balance.Because PVA has hydrophilicity and increases the water absorption of the membrane,the addition of PVA will increase the amount of evaporated water.The surface characteristics of GO membrane and PVA-GO composite membrane were analyzed by SEM.It is found that the GO membrane without PVA has a fibrous filament structure,and the fibers are clearly visible.After adding PVA,the fiber is wrapped by PVA,indicating that the light absorption capacity of the film is enhanced.When 6wt%PVA is added,the non-woven fibers are completely wrapped by PVA.When using a xenon lamp to conduct water evaporation experiments on the two films,the evaporation rate of the GO film reaches 1.67 kg/(m^(2)·h),and the evaporation rate of the PVA-GO composite film reaches 1.85 kg/(m^(2)·h).In addition,the layered structure of GO appears in the GO film,and the ultraviolet-visible-near-infrared spectroscopy shows a good light absorption ability,and it has a good photothermal conversion ability in the photothermal evaporation experiment.The PVA-GO composite film has better photothermal conversion performance and light absorption when the PVA mass concentration is 4wt%.