Soy protein isolate (SPI), a ubiquitous and readily available biopolymer, has drawn increasing attention because of its sustainability, abundance, and low price. However, the poor mechanical properties, tedious performance adjustments, irreversible damage, and weak microorganism resistance have limited its applications. In this study, a facile but delicate strategy is proposed to fabricate an excellently selfhealable and remarkably antibacterial SPI-based material with high mechanical strength by integrating polyethyleneimine (PEI) and metal ions (Cu(II) or Zn(II)). The tensile strengths of the SPI/PEI-Cu-0.750 and SPI/PEI-Zn-0.750 films reach up to 10.46 ± 0.50 and 9.06 ± 0.62 MPa, which is 367.06 and 306.28% strength increase compared to that of neat SPI film, respectively. Due to abundant non-covalent bonds and low glass transition temperature of the network, both SPI/PEI-Cu and SPI/PEI-Zn films exhibit a satisfactory self-healing behavior even at room temperature. Furthermore, SPI/PEI-Cu and SPI/PEI-Zn films demonstrate high bacterial resistance against Escherichia coli and Staphylococcus aureus. This facile strategy of establishing dynamic networks in a biomaterial with numerous excellent properties will enormously expand the scope of its applications, especially in the field of recyclable and durable materials.

Tough and biodegradable soy protein isolate film with excellent UV barrier performance by hyperbranched polyester, and cardanol derivative.

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reported to have prepared wood-based inorganic composites by sol-gel processes, which possessed comparatively high dimensional stability and flame resistance. Takeshi et al. (1991Takeshi et al. ( , 1992Takeshi et al. ( , 1993, taking sodium silicate as a main reagent, improved the flame resistance, decay resistance and dimensional stability of wood, but compromised the mechanical strength and anti-hygroscopicity. Yamaguchi (1994aYamaguchi ( , 1994b treated wood samples with silica sol, in which phosphoric acid was added to adjust its pH value and enhanced the bending strength and dimensional stability of wood. Fumie et al. (1998) prepared wood-based inorganic composites, which were highly antibacterial, by applying an antibacterial reagent during sol-gel processes. Li et al. (2001) studied the preparation of acetylated and propionylated woodsilicate composites with fairly good dimensional stability and fire-resistance. It was also reported (Qian et al., 2001) that impregnating fir wood with urea-formaldehyde resin followed by hot-pressing could improve its mechanical strength. Shen et al. (2005) modified fir wood with natural organic compounds and enhanced its hardness and abrasion resistance. Applying phenol-formaldehyde resin, Fang et al. (1999) and Furuno et al. (2004) respectively treated poplar wood and Japanese cedar wood, enhancing the dimensional stability and mechanical strength of poplar wood and the dimensional stability and decay resistance of cedar wood. In addition, wood-SiO 2 composites with comparatively high dimensional stability were prepared by Wang et al. (1996Wang et al. ( , 1998 and Sun et al. (1998). It was also reported that tetraethyl orthosilicate (TEOS) and tetrabutyl titanate (Ti(OBu) 4 ) could be used to improve the permeability and hardness of wood (Xu et al., 2005).However, almost all of the previous studies emphasized only on the modification of part of the properties of wood rather than all of them; some treatments even impaired some good performances of wood.Nano-materials and nano-technology have been successfully utilized in many fields. For instance, some nano-oxides markedly enhanced the abrasion resistance and self-cleaning function of some paints. It was reported that nano-SiO 2 was beneficial in improving the bonding strength of UF adhesive Abstract In order to improve wood properties of triploid clones of Populus tomentosa, urea-formaldehyde (UF) resin was compounded with nano-SiO 2 , coupling agents and flame retardants in different ways to prepare five kinds of modifiers. The poplar wood samples were impregnated with the modifiers and heated to prepare UF-SiO 2 -wood composites. The antiswelling efficiency, resistance of water absorption, oxygen index and hardness of the composites were measured. Results show that all of the modifiers reduced water absorption of poplar wood and enhanced flame resistance and hardness. Nano-SiO 2 showed a marked effect in improving the hardness of wood. In addition, all of the modifiers, except UF-C-SiO 2 -polymer, improved the dimens...

Amino acids, which are important compatible solutes, play a significant role in probiotic lyophilization. However, studies on the functions of Bifidobacterium during freeze-drying are limited. Therefore, in this study, we compared the freeze-drying survival rate of Bifidobacterium longum CCFM 1029 cultivated in different media containing different kinds of compatible solutes. We found that the addition of 21 g/L proline to the culture media substantially improved the freeze-drying survival rate of B. longum CCFM 1029 from 18.61 ± 0.42% to 38.74 ± 1.58%. Interestingly, this change has only been observed when the osmotic pressure of the external culture environment is increased. Under these conditions, we found that proline accumulation in this strain increased significantly. This change also helped the strain to maintain its membrane integrity and the activity of some key enzymes during freeze-drying. Overall, these results show that the addition of proline can help the strain resist a tough environment during lyophilization. The findings of this study provide preliminary data for producers of probiotics who wish to achieve higher freeze-drying survival rates during industrial production.