Studying new wood composites through nano science and technology (NSC) will develop new compounding theory of wood, and accelerate the combination of new technology, wood science, material science and other discipline...Studying new wood composites through nano science and technology (NSC) will develop new compounding theory of wood, and accelerate the combination of new technology, wood science, material science and other disciplines. The compounding of wood and inorganic MMT on nanoscale molecular level has high potential to greatly improve the mechanical properties, fire retardance, abrasion resistance, decay resistance, dimensional stability and other properties of wood. Based on the great achievements of polymer/montmorillonite (MMT) nanocomposites, this paper reviewed nano intercalation compounding methods (i.e. in-situ intercalative polymerization and direct polymer intercalation), and discussed the structure, properties and modification of montmorillonite (MMT). According to the main chemical components and particular structure of wood, the authors discussed the liquefaction and plasticization of wood, compared the dissolvability and meltability between wood and polymer, and then systematically put forward the basic idea, technological processes and schematic diagram to prepare wood/MMT nanocomposites (WMNC). The key technology to prepare WMNC is either to introduce delaminated MMT nanolayers into wood with the help of some intermediate polymers, or to obtain liquefied wood or plasticized wood from the complicated natural composite. It is applicable and effective to realize wood/MMT nanoscale compounding with the help of proper intercalation agent and medium polymer through the proposed 搊ne-step?or 搕wo-step?impregnating processes.展开更多
With montmorillonite （MMT） organically modified as organophilic MMT （OMMT） and water-soluble phenol formaldehyde resin （PF） as intermediate, Chinese fir （Cunningharnia lanceolata） wood/MMT nanocomposites （WMN...With montmorillonite （MMT） organically modified as organophilic MMT （OMMT） and water-soluble phenol formaldehyde resin （PF） as intermediate, Chinese fir （Cunningharnia lanceolata） wood/MMT nanocomposites （WMNC） were prepared via nano intercalation compounding and characterized by XRD, SEM and FTIR. Results show that： 1） the preparation of OMMT is very successful; 2） the self-made PF can effectively intercalate into MMT to increase markably its gallery distance and even exfoliate its nano silicate laminae; 3） the XRD analysis indicates that some exfoliated MMT enters the non-crystallized region of microfibrils in wood cell walls and the crystallinity degree of wood in WMNC decreases; 4） the SEM graphs show that multiform MMT exists in WMNC. Some grains block in wood cell lumen, some layers adhere to the wood surface of the inner cell wall and some exfoliated nanolaminae even insert into wood cell walls; and 5） the FTIR analysis suggests that MMT and wood in WMNC perhaps interact via certain chemical bonding.展开更多
The hydrated-titanium-oxide/montmorillonite composite samples were prepared using a hydrolysation- intercalation composite method by controlling the amount of TiOSO4·2H2O. The TiO2/montmorillonite composite sampl...The hydrated-titanium-oxide/montmorillonite composite samples were prepared using a hydrolysation- intercalation composite method by controlling the amount of TiOSO4·2H2O. The TiO2/montmorillonite composite samples were got after calculated at 700℃ and 1100 ℃. The results show that: when the value of Ti/montmorillonite is 12.5 mmol/g, the c axis of hydrated-titanium-oxide/ montmorillonite composite sample began to disorder, moreover, the crystal size of anatase is just 13.4nm in the TiO2/montmorillonite composite sample calculated at 700 ℃, and after calculated at 1100 ℃, the crystal size of anatase is 55.8 nm, and the relative content of anatase reaches the highest (55.7%). Compared with pure TiO2 nano-particle sample, TiO2/montmorillonite composite sample has a higher phase transition temperature from anatase phase to rutile phase and smaller crystal size of TiO2. Montmorillonite structure layer has a significant blocking effect on TiO2 phase transformation and grain growth, and the blocking effect reaches saturation when the value of Ti/montmorillonite is 12.5 mmol/g.展开更多
Compared with traditional surfactant-stabilised emulsions, Pickering emulsions, stabilised by clay nanoparticles, have the advantages of strong interface stability, strong versatility, and low toxicity. Moreover, they...Compared with traditional surfactant-stabilised emulsions, Pickering emulsions, stabilised by clay nanoparticles, have the advantages of strong interface stability, strong versatility, and low toxicity. Moreover, they have excellent application potential in the fields of food and medicine. In this study, a food-grade Pickering emulsion stabiliser was prepared by physically adsorbing the cationic surfactant ethyl lauroyl arginate (LAE) on the surface of nano-montmorillonite (NMMT). Different LAE/NMMT combinations were assessed for their capacity to stabilise an oil-in-water emulsion at a low solid concentration (0.5%, w/v). The controllability of the droplet diameter and stability of the Pickering emulsions can be realised by changing the content of LAE. Scanning electron microscopy (SEM), and laser confocal microscopy (CLSM) confirmed the successful preparation of sunflower oil Pickering emulsion droplets stabilised by LAE/NMMT (0.0075%/1%). Additionally, the LAE/NMMT studied in this work could be used as a highly effective antibacterial surfactant with inorganic nanoparticles to efficiently stabilise Pickering emulsions, thus expanding the potential of preparing edible Pickering emulsion formulae.展开更多
The nano intercalation compounding of wood and MMT has important implications for the modification of wood and for the development of new materials. With water-soluble phenol formaldehyde resin as an intermediary, the...The nano intercalation compounding of wood and MMT has important implications for the modification of wood and for the development of new materials. With water-soluble phenol formaldehyde resin as an intermediary, the nanocomposites of Chinese fir （Cunningharnia lanceolata） wood and montmorillonite （MMT） were prepared via three impregnation methods, i.e. normal pressure, once and twice vacuum methods. Based on the weight percent gain （WPG） of impregnated wood, the effects of compounding wood and MMT in terms of concentration, impregnating temperature and time, wood moisture content and wood extraction treatments, on sapwood and heartwood are discussed. Results show that： 1） the optimum MMT concentration in the impregnation solution is 3% for sapwood and 5% for heartwood; 2） room temperature is suitable in practice; 3） treatment pressure should be set at a high enough value in order to ensure sufficient permeation; 4） the effects of different impregnation methods on sapwood and heartwood are different, the heartwood extractives affect WPG significantly; cell wall permeability of sapwood is better than that of heartwood; 5） the cold water, hot water and benzene-ethanol solution extractions can all greatly improve the permeability of heartwood, hot water can dissolve some hemicellulose of low aggregation and hot water extraction improves wood cell wall permeability; 6） with an increase in wood moisture content, the permeable space in wood is reduced, but with a certain amount of water, instantaneous spaces are created and the permeation dynamic increases. This effect is especially apparent for difficult impregnating situations in heartwood and impregnation under normal pressure.展开更多
基金Supported by the National Natural Science Foundation of China (Grant No. 30271055)
文摘Studying new wood composites through nano science and technology (NSC) will develop new compounding theory of wood, and accelerate the combination of new technology, wood science, material science and other disciplines. The compounding of wood and inorganic MMT on nanoscale molecular level has high potential to greatly improve the mechanical properties, fire retardance, abrasion resistance, decay resistance, dimensional stability and other properties of wood. Based on the great achievements of polymer/montmorillonite (MMT) nanocomposites, this paper reviewed nano intercalation compounding methods (i.e. in-situ intercalative polymerization and direct polymer intercalation), and discussed the structure, properties and modification of montmorillonite (MMT). According to the main chemical components and particular structure of wood, the authors discussed the liquefaction and plasticization of wood, compared the dissolvability and meltability between wood and polymer, and then systematically put forward the basic idea, technological processes and schematic diagram to prepare wood/MMT nanocomposites (WMNC). The key technology to prepare WMNC is either to introduce delaminated MMT nanolayers into wood with the help of some intermediate polymers, or to obtain liquefied wood or plasticized wood from the complicated natural composite. It is applicable and effective to realize wood/MMT nanoscale compounding with the help of proper intercalation agent and medium polymer through the proposed 搊ne-step?or 搕wo-step?impregnating processes.
文摘With montmorillonite （MMT） organically modified as organophilic MMT （OMMT） and water-soluble phenol formaldehyde resin （PF） as intermediate, Chinese fir （Cunningharnia lanceolata） wood/MMT nanocomposites （WMNC） were prepared via nano intercalation compounding and characterized by XRD, SEM and FTIR. Results show that： 1） the preparation of OMMT is very successful; 2） the self-made PF can effectively intercalate into MMT to increase markably its gallery distance and even exfoliate its nano silicate laminae; 3） the XRD analysis indicates that some exfoliated MMT enters the non-crystallized region of microfibrils in wood cell walls and the crystallinity degree of wood in WMNC decreases; 4） the SEM graphs show that multiform MMT exists in WMNC. Some grains block in wood cell lumen, some layers adhere to the wood surface of the inner cell wall and some exfoliated nanolaminae even insert into wood cell walls; and 5） the FTIR analysis suggests that MMT and wood in WMNC perhaps interact via certain chemical bonding.
文摘The hydrated-titanium-oxide/montmorillonite composite samples were prepared using a hydrolysation- intercalation composite method by controlling the amount of TiOSO4·2H2O. The TiO2/montmorillonite composite samples were got after calculated at 700℃ and 1100 ℃. The results show that: when the value of Ti/montmorillonite is 12.5 mmol/g, the c axis of hydrated-titanium-oxide/ montmorillonite composite sample began to disorder, moreover, the crystal size of anatase is just 13.4nm in the TiO2/montmorillonite composite sample calculated at 700 ℃, and after calculated at 1100 ℃, the crystal size of anatase is 55.8 nm, and the relative content of anatase reaches the highest (55.7%). Compared with pure TiO2 nano-particle sample, TiO2/montmorillonite composite sample has a higher phase transition temperature from anatase phase to rutile phase and smaller crystal size of TiO2. Montmorillonite structure layer has a significant blocking effect on TiO2 phase transformation and grain growth, and the blocking effect reaches saturation when the value of Ti/montmorillonite is 12.5 mmol/g.
文摘Compared with traditional surfactant-stabilised emulsions, Pickering emulsions, stabilised by clay nanoparticles, have the advantages of strong interface stability, strong versatility, and low toxicity. Moreover, they have excellent application potential in the fields of food and medicine. In this study, a food-grade Pickering emulsion stabiliser was prepared by physically adsorbing the cationic surfactant ethyl lauroyl arginate (LAE) on the surface of nano-montmorillonite (NMMT). Different LAE/NMMT combinations were assessed for their capacity to stabilise an oil-in-water emulsion at a low solid concentration (0.5%, w/v). The controllability of the droplet diameter and stability of the Pickering emulsions can be realised by changing the content of LAE. Scanning electron microscopy (SEM), and laser confocal microscopy (CLSM) confirmed the successful preparation of sunflower oil Pickering emulsion droplets stabilised by LAE/NMMT (0.0075%/1%). Additionally, the LAE/NMMT studied in this work could be used as a highly effective antibacterial surfactant with inorganic nanoparticles to efficiently stabilise Pickering emulsions, thus expanding the potential of preparing edible Pickering emulsion formulae.
基金This study was financially supported by the National Natural Science Foundation of China （Grant No. 30271055）.
文摘The nano intercalation compounding of wood and MMT has important implications for the modification of wood and for the development of new materials. With water-soluble phenol formaldehyde resin as an intermediary, the nanocomposites of Chinese fir （Cunningharnia lanceolata） wood and montmorillonite （MMT） were prepared via three impregnation methods, i.e. normal pressure, once and twice vacuum methods. Based on the weight percent gain （WPG） of impregnated wood, the effects of compounding wood and MMT in terms of concentration, impregnating temperature and time, wood moisture content and wood extraction treatments, on sapwood and heartwood are discussed. Results show that： 1） the optimum MMT concentration in the impregnation solution is 3% for sapwood and 5% for heartwood; 2） room temperature is suitable in practice; 3） treatment pressure should be set at a high enough value in order to ensure sufficient permeation; 4） the effects of different impregnation methods on sapwood and heartwood are different, the heartwood extractives affect WPG significantly; cell wall permeability of sapwood is better than that of heartwood; 5） the cold water, hot water and benzene-ethanol solution extractions can all greatly improve the permeability of heartwood, hot water can dissolve some hemicellulose of low aggregation and hot water extraction improves wood cell wall permeability; 6） with an increase in wood moisture content, the permeable space in wood is reduced, but with a certain amount of water, instantaneous spaces are created and the permeation dynamic increases. This effect is especially apparent for difficult impregnating situations in heartwood and impregnation under normal pressure.
