| Cellulose materials are a kind of green,renewable and biodegradable natural polymer compounds which are widely distributed and easy to obtain,they are one of the most potential biomass materials.In this paper,the natural cellulose materials are proposed as the research object.By using different synthesis and compounding methods,we used one-dimensional nanocellulose,which has unique nanostructure,good mechanical properties and flexibility,the three-dimensional cellulose materials which have porous,multi-level and orderly multi-scale hierarchical structure,filtration,adsorption and energy absorption properties to combine with functional semiconductors or conductive nanomaterials to build cellulose composite aerogels with three-dimensional network structure and electromagnetic shielding paper and applied to dye adsorption and electromagnetic shielding.At the same time,metallic compounds materials with special functions are introduced,which enriches the multi functionality of cellulose based materials,widens its application fields,and realizes the high-value utilization of cellulose base materials.The main conclusions were as follows:The porous zeolitic imidazolate frameworks（ZIF-8）grown on cellulose aerogels by using an in-situ growth method.Zinc nitrate and 2-methimazole were used as precursors to prepare the ZIF-8@CNF composite aerogels.The results show that ZIF-8 is evenly distributed on the pore walls of aerogels,and the composite aerogels exhibit stable three-dimensional network porous structure.With increasing the load content of ZIF-8 to 34.40 wt%,the specific surface area of ZIF-8@CNF aerogels reaches 455.06m2·g-1.The adsorption capacity of ZIF-8@CNF composite aerogels showed that the maximum adsorption capacity of MB,MO and I-reached 431.03 m2·g-1,121.95 m2·g-1 and 427.35 m2·g-1 respectively.The photosensitive semiconductor materials and semiconducting graphene materials were induced to the pure CNF aerogels template by a hydrothermal method to prepare cellulose based composite aerogel adsorption materials with photocatalytic properties.The results show that the Ti O2/GO@CNF aerogels possess a typical 3D network structure,further,under ultraviolet light irradiation conditions,When the amount of adsorbent is 0.04 g and the reaction p H value is 6,the maximum adsorption capacity of Ti O2/GO@CNF composite aerogel to MB dye molecules is 208 m2·g-1.The adsorption process follows the pseudo-second-order adsorption kinetics and Langmuir isotherm model,what’s more,the composite aerogel exhibits good reusable property.In order to improve the photocatalytic degradation performance of composite aerogels under visible light,a Ti O2/WO3 heterojunction was constructed and dispersed on graphene oxide substrate under hydrothermal conditions.Furthermore,Ti O2/WO3/GO@CNF composite aerogel were prepared by loading the catalyst onto the pure CNF aerogels.The results show that the composite aerogels still persist the 3D network porous structure,after combining with photocatalyst and the addition of WO3 can effectively reduce the forbidden band width and enhance the absorption of visible light.Under the visible light irradiation of Xenon lamp,the maximum adsorption capacity of composite aerogel for MB dye reached to 262 m2·g-1 and the adsorption performance follow pseudo-second-order kinetic model and Langmuir adsorption isotherm model,finally,composite aerogel also shows a high recycling performance.The Ni/GO@CNF electromagnetic shielding paper with shell like layered structure was prepared through a vacuum assisted filtration method by compounding Ni doped GO composite with one-dimensional nanocellulose.The effects of different addition ratios of Ni/GO composite and CNF were explored and it showed an obvious effect on the mechanical properties of Ni/GO@CNF electromagnetic shielding paper.The results show that the electromagnetic shielding paper has good mechanical properties.When the ratio of Ni/GO:CNF=2:8,the tensile strength of the paper reaches 104.51 MPa,and with the addition of Ni/GO,an electron transport channel was formed on the cellulose network,the conductivity of the electromagnetic shielding paper increased to 2002.31 s·m-1.It shows that in X-band,the electromagnetic shielding performance dominated by electromagnetic wave absorption,and the maximum EMI value is 30.09 d B.In order to make full use of cellulose materials with high porosity,multi-scale hierarchical structure and filter energy absorption properties.A 3D cellulose matrix framework was obtained by removing almost lignin and hemicellulose through a chemical pretreatment from basha wood chips.After that,the2D conductive material MXene was immersed into the cellulose matrix by the method of vacuum pumping-pressure impregnation-mechanical compression to get a cellulose/MXene electromagnetic shielding paper with nacre like layered structure.The results show that the tensile strength of the electromagnetic shielding paper can reach 210 MPa,the conductivity is 2260.70 s·cm-1,and the maximum electromagnetic shielding efficiency in X-band can reach 60.38 d B,which is far beyond the commercial standard of electromagnetic shielding material.Using this method,wood is directly used after simple chemical pretreatment,which can reduce the complicated procedures of pulping or traditional chemical treatment process to prepared papers,and it also makes the preparation process of cellulose based materials more simple and efficient to realize the multiple functions and realizing high-value utilization. |
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