RSC Advances
·
2016
·Vol. 6
·期 40
·33547-33553
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IF 3.289
Kai Li,Zhengdong Pan,Cheng Guan,Hua Zheng,Kun Li,Hong Zhang
Shellac is an ancient oligomer and had been widely used in many fields in the past. Recently, we found that these low-molecular weight, biodegradable and amphiphilic biomacromolecules could aggregate to fabricate multi-scale materials. In this study, gluconic acid lactone (GDL) was employed as a H+ donor, and mixed with shellac-COONa to prepare a shellac hydrogel. It was found that in the beginning of gelation, as the hydrolysis of GDL proceeded, the amphiphilic molecules shellac-COONa changed to shellac-COOH and assembled into the nano-size vesicles. Furthermore, these vesicles constructed by shellac-COOH, similar to asymmetric gemini surfactants, could aggregate together to fabricate the network of the shellac hydrogel by the hydrophobic association between two sets of short hydrophobic chains from two adjacent vesicles. The shellac hydrogel has excellent mechanical properties and nice degradation behavior, and the compressive fracture stress, strain and compress modulus could be 7.6 MPa, 43.7%, 61 MPa, which means it can be used as a new kind of soft material, such as high mechanical performance bio-based foams.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 60
·55618-55625
·
IF 3.289
Kun Li,Hua Zheng,Hong Zhang,Wen-wen Zhang,Kai Li,Juan Xu
This study made use of a novel totally chlorine-free (TCF) bleaching approach to prepare bleached shellac. Some single factor experiments were employed to investigate the effects of the main factors in the H2O2 bleaching method. A new chlorine-free bleached shellac resin was obtained in the Box–Behnken design responsive surface optimal experimental conditions (pH, 9.0–11.0; 1.33 mL g−1, concentration of 30% hydrogen peroxide; 2.0 h, dropping time of hydrogen peroxide; 7.2 h, bleaching time; 90 °C, temperature). The yield and color index of the bleached shellac obtained under the optimal experimental conditions were 80.84% and 0.5675 respectively. The result of the physicochemical property test, IR spectrum and DSC characterization indicate that the properties of H2O2 bleached shellac are similar to commercially refined shellac resin. Moreover, it is noteworthy that the H2O2 bleached shellac was remarkable in alcohol solubility and thermal lifetime tests. It had a higher acid value and a lower softening point compared with commercially refined shellac resin, which can be applied safely in many fields including food and medical industries without chlorine residues.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2025
·
IF 5.4
Lingsu Zhang,Liwei Qi,Weifu Dong,Tatsuo Kaneko,Hongji Zhang,Mingqing Chen,Dongjian Shi
To reduce the cellular components damage and marine ecosystem pollution caused by common chemical sunscreens, natural or biologically derived sunscreen ingredients have become one of the major priorities, due to their effective protection against ultraviolet (UV) radiation while minimizing potential health risks. Herein, we develop a novel sunscreen agent, shellac, that is refined from biological sources with good biocompatibility and amphiphilicity. Shellac was first modified with natural source materials through amidation reaction, dextran (DEX), coumarin (CM) or cinnamic (CA), in which the former provided the hydrogen-bonding interaction, and the latter two provided UV absorption performance. The structures of these modified products were confirmed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier Transform Infrared (FTIR) and Proton Nuclear Magnetic Resonance ( 1 HNMR). Then, a plant sunscreen, sinapic acid (SA) was encapsulated into modified shellac nanoparticles (MSNPs), which showed uniform spherical structure observed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Zeta potential and nanoparticle analyzer, and the resultant MSNPs were further blended with sunscreen cream matrix. The sunscreen cream showed good enhanced UV-absorption capacity, and the Sun Protection Factor (SPF) increased to above 50. In addition, FTIR and UV-Vis absorption spectra were carried out to explore the possible synergistic effect between functional shellac, SA and sunscreen cream matrix. The obtained MSNPs also have superior biosafety according the cytotoxicity test, which makes them an ideal skin sunscreen agent.
研究领域:
材料科学
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生物学
·
化妆品科学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Jinju Ma,Yupeng Liu,Juan Xu,Youqing Chen,Lanxiang Liu,Hong Zhang
Fresh-cut products are extremely perishable due to the processing operations, and the atmosphere environment, especially CO 2 , O 2 and H 2 O, could profoundly affect their shelf life. Herein, an insect “lac blanket”-mimetic and facile strategy was proposed for fresh-cut vegetables preservation, employing porous shellac hydrogel microparticles as gas “switches” in chitosan film to regulate CO 2 , O 2 and H 2 O vapor permeability. Thus, the shellac hydrogel/chitosan hybrid film presented the controllable and wide range of gas permeability, compared with the chitosan film. The shellac-COOH nanoscale vesicles aggregated to form shellac hydrogel network via hydrophobic binding. The shellac hydrogel microparticles played a certain lubricating effect on the hybrid film casting solution. The hydrogen bond network between shellac hydrogel and chitosan contributed to the excellent mechanical properties of the hybrid film. The hybrid film also exhibited remarkable water-resistant, antifogging properties, optical transparency and degradability. The hybrid packaging films prepared through this strategy could adjust the internal gas (CO 2 , O 2 , H 2 O and ethylene) contents within the packages, and further exhibited admirable preservation performance on three fresh-cut vegetables with different respiratory metabolisms. This gas permeation-controlled strategy has great potential in fresh food preservation and various other applications that need a modified atmosphere.
研究领域:
食品科学
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材料科学
·
生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）