| Porous materials are widely used in packaging,food and chemical industries.The traditional petroleum based porous materials are non-renewable and easy to cause environmental pollution.Therefore,environmentally and friendly biomass based foams are the inevitable development direction of porous materials.Soybean oil based functional porous materials were prepared by Pickering emulsion template method.Using the Pickering emulsion templating method to prepare soybean oil-based functional porous materials,the raw materials and preparation process are environmental-friendly,and the performance of solid particles as emulsion stabilizers is tunable and controllable,which provides a green and environmentally friendly new method to prepare functional biomass based porous materials.In this study,2,2,6,6-Tetramethylpiperidine(TEMPO)oxidized cellulose nanofiber(TOCNF)combined nisin was used as solid particle stabilizers.Acrylate epoxy soybean oil(AESO),a derivative of soybean oil,was used as oil phase for the preparation of stable water in oil(W/O)type Pickering emulsion.Porous materials were prepared by emulsion template method and the related properties of foam were studied.The main research contents and results are as follows:(1)Preparation of TOCNF stabilized Pickering emulsions:Pickering emulsion was prepared with AESO as oil phase and TOCNF as stabilizer.The influence of oil to water ratio and stabilizer concentration on emulsion were explored.Emulsion type was determined by dilution method.The influence of oil-water ratio and solid particle concentration on emulsion stability were studied.Through stability test and rheological property analysis,the best ratio was determined as 0.30wt%TOCNF concentration and the oil to water ratio 7:3.The Pickering emulsion prepared under this condition did not precipitate in aqueous phase,the internal structure of emulsion is stable and the droplet size is the smallest.(2)Preparation of TOCNF/nisin stabilized Pickering emulsion:Nisin was used to adjust the wettability of TOCNF on oil-water interface.Nisin and TOCNF are combined to prepare composite particles by electrostatic attraction.Pickering emulsion is prepared by using AESO as oil phase.The effects of nisin addition dosage on the stability and rheological properties of the emulsions prepared were investigated.The results showed that the Pickering emulsion prepared by composite particles of 1-5wt%nisin dosage were water in oil(W/O)type.When the nisin dosage was 3wt%,the droplet diameter of the emulsion was 2.22?m,and the dynamic viscoelastic analysis showed that the emulsion had the best internal structure stability.(3)Preparation of thermosetting composite porous materials by Pickering emulsion template method:At 3wt%initiator dibenzoyl peroxide(BPO)and 90°C,the oil phase AESO was curved by free radical polymerization to obtain composite foam.Foam was prepared by three solid particle stabilizers of TOCNF,nisin and TOCNF/nisin complex particles respectively,and the density,mechanical strength,antibacterial properties and thermal stability of them were investigated.The results showed that the porous materials prepared by Pickering emulsion stabilized by complex particles has porous structure with a density of 0.69 g/cm~3 and a compressive strength of 1.68 MPa.The thermal conductivity is 0.197 W/(m·K),and the bacteriostasis rate for against L.monocytogenes is 91.33%.Compared with the porous materials prepared by TOCNF only,TOCNF/nisin complex foam has the smallest density,the highest compression strength,the lowest thermal diffusivity and remarkable antibacterial property,which may have potential applications in the field of refrigerated heat preservation. |
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