bionanocomposites

生物纳米复合材料
  • 文章类型: Journal Article
    这项研究的主要目标是将聚吡咯(PPy)和各种浓度的氮掺杂碳量子点(N-CQDs)集成到聚丙烯酰胺(PAm)接枝的羟乙基纤维素(gHEC)中,以生产gHEC@PPy@N-CQDs具有环境可持续特性的生物复合材料。通过分析X射线衍射(XRD)和傅立叶变换红外光谱(FTIR)获得的数据,证明了gHEC@PPy基质内N-CQD的嵌入和均匀分布。使用热重分析(TGA和DTG)以及扫描和透射电子显微镜对样品进行分析。PPy和4%N-CQD在基质内的改善的分散导致石墨烯杂化金属生物纳米复合材料的电特性增强。在gHEC@PPy@N-CQDs生物纳米复合材料中观察到的特殊光学和光致发光发射可归因于N-CQDs的表面基团以及CN和CN之间的跃迁。该假设表明,这些因素在确定观察到的光学特性中起着重要作用。主要目标是确定这些生物纳米复合材料在多个领域的独特和迷人的应用,包括电子产品,具有广泛颜色的光学和发光器件,和生物成像应用。
    The major objective of this research revolves around the integration of polypyrrole (PPy) and various concentrations of nitrogen-doped carbon quantum dots (N-CQDs) into a polyacrylamide (PAm)-grafted hydroxyethyl cellulose (gHEC) to produce gHEC@PPy@N-CQDs bionanocomposites that possess environmentally sustainable properties. The intercalation and uniform distribution of N-CQDs inside the gHEC@PPy matrix have been demonstrated through the analysis of data obtained from X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The samples underwent analysis using thermogravimetric analysis (TGA and DTG) as well as scanning and transmission electron microscopy. The improved dispersion of PPy and 4 % N-CQDs inside the matrix led to enhanced electrical characteristics of the graphene-hybridized metal bionanocomposite. The peculiar optical and photoluminescence emission observed in the gHEC@PPy@N-CQDs bionanocomposites can be attributed to the surface groups of N-CQDs and the transition between CN and CN. This hypothesis suggests that these factors play a significant role in determining the observed optical properties. The main goal is to identify distinctive and captivating applications for these bionanocomposites across several domains, including electronics, optical and light-emitting devices with a broad spectrum of colors, and bioimaging applications.
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  • 文章类型: Journal Article
    通过放射化学中子活化分析鉴定了埃及磷酸中的有害元素。在第二座埃及核研究反应堆中,沉淀产生并检查以识别多种类型的污染物(Ce,Co,Cr,等。).新的生物纳米复合材料有效地去除高比例的每个Ce,Th,Pa,U,Np,Zn,和Co(100%),Cr的百分比略低(65-85%),Sc,和模拟溶液中的Fe,表明有希望净化磷酸。
    Harmful elements in Egyptian phosphoric acid were identified by radiochemical neutron activation analysis. In the Second Egyptian Nuclear Research Reactor, precipitates were created and examined to identify many types of contaminants (Ce, Co, Cr, etc.). New bionanocomposite materials effectively removed with a high proportion each of Ce, Th, Pa, U, Np, Zn, and Co (100%) and a somewhat lower percentage (65-85%) for Cr, Sc, and Fe from simulated solutions, suggesting promise for purifying phosphoric acid.
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  • 文章类型: Journal Article
    低介电常数和电绝缘应用的材料需要重新设计,以实现可持续发展。为了应对这一挑战,拟议的研究重点是用于电绝缘应用的3D打印纤维素基复合材料的介电和机械优化。两种不同的填料,微晶纤维素(MCC)和纳米晶纤维素(NCC),被用来制造生物复合材料和生物复合材料,分别,共混到聚乳酸(PLA)基质中。填充比的影响,打印温度,使用不完全L9(3^3)阶乘设计测量了填料含量对介电和机械性能的影响。结果表明,填充率是影响测试性能的最重要因素,直接归因于材料的极化和机械性能的增加。第二大影响因素是填料含量,增加所测试复合材料的极性并降低生物复合材料和生物纳米复合材料的韧性。最后,印刷温度没有显著影响。填充率为50%的生物复合材料的结果,200°C打印温度,重量含量为15%的MCC比相同条件下印刷的纯PLA的拉伸模式刚度高60%,同时表现出比100%填充率印刷的纯PLA更低的介电性能。这些结果为新的轻质电绝缘材料铺平了道路。
    Materials for low-permittivity and electrical insulation applications need to be re-engineered to achieve sustainable development. To address this challenge, the proposed study focused on the dielectric and mechanical optimization of 3D-printed cellulose-based composites for electrical insulation applications. Two different fillers, microcrystalline cellulose (MCC) and nanocrystalline cellulose (NCC), were used to create biocomposites and bionanocomposites, respectively, blended into a polylactic acid (PLA) matrix. The effects of infill ratio, printing temperature, and filler content on dielectric and mechanical properties were measured using an incomplete L9 (3^3) factorial design. The findings showed that the infill ratio was the most significant factor influencing the properties tested, directly attributable to the increase in material availability for polarization and mechanical performance. The second most influential factor was the filler content, increasing the polarity of the tested composites and decreasing the toughness of the biocomposites and bionanocomposites. Finally, printing temperature had no significant effect. Results for the biocomposites at a 50% infill ratio, 200 °C printing temperature, and a weight content of MCC of 15% gave a 60% higher tensile-mode stiffness than neat PLA printed under the same conditions, while exhibiting lower dielectric properties than neat PLA printed with a 100% infill ratio. These results pave the way for new lightweight materials for electrical insulation.
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  • 文章类型: Journal Article
    生物复合材料为塑料废物危机提供了一个有希望的解决方案。尽管木薯淀粉显示出作为生物塑料材料的潜力,它的特点是机械性能低,热稳定性差,和高吸水性由于其亲水性。增加材料的柔韧性,降低氧气和水蒸气的透过率,例如果糖和二氧化钛(TiO2)的添加剂可以掺入到材料中。TiO2纳米颗粒通常用于农业中以增强养分释放并促进植物生长。在这项研究中,X射线衍射分析表明,TiO2降低了晶体尺寸,同时增加了生物纳米复合材料的结晶度。傅里叶变换红外光谱分析显示在3397cm-1处出现吸收峰,表明TiO2和淀粉-OH基团之间存在氢键,和773cm-1处的峰值,表明Ti-O-Ti拉伸振动的强度随着TiO2的掺入而增加。吸水率结果证实,TiO2的添加增强了生物复合材料对水蒸气和水分的抵抗力,拉伸强度从0.11增加到0.49MPa,杨氏模量从2.48增加到5.26MPa,在具有TiO2的生物纳米复合材料中,断裂伸长率从21.46%降低到2.36%。此外,添加TiO2,生物纳米复合材料的生物降解速率降低,有利于提高植物营养成分。
    Bionanocomposites offer a promising solution to the plastic waste crisis. Although tapioca starch shows potential as a bioplastic material, it is characterized by low mechanical properties, poor thermal stability, and high water absorption owing to its hydrophilic nature. To increase the flexibility of the material and reduce the transmission rate of oxygen and water vapor, additives such as fructose and titanium dioxide (TiO2) can be incorporated into the material. TiO2 nanoparticles are commonly utilized in agriculture to enhance nutrient release and promote plant growth. In this study, X-ray diffraction analysis revealed that TiO2 reduced crystal size while increasing the crystallinity of bionanocomposites. Fourier-transform infrared spectroscopy analysis revealed an absorption peak at 3397 cm-1, indicating hydrogen bonding between TiO2 and starch-OH groups, and a peak at 773 cm-1, indicating an increase in the intensity of Ti-O-Ti stretching vibrations with the incorporation of TiO2. Water absorption rate results confirmed that TiO2 addition enhanced bionanocomposite resistance to water vapor and moisture, evidenced by increased tensile strength from 0.11 to 0.49 MPa and Young\'s modulus from 2.48 to 5.26 MPa, as well as decreased elongation at break from 21.46 % to 2.36 % in bionanocomposites with TiO2. Furthermore, with TiO2 addition, the biodegradation rate of the bionanocomposites decreased, which is beneficial for enhancing plant nutrient content.
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  • 文章类型: Journal Article
    基于壳聚糖(CS)开发了用于酸奶油包装的可生物降解可食用膜,羟乙基纤维素(HEC),橄榄叶提取物(OE),和二氧化钛纳米颗粒(TiO2-NP)。对制备的CS/HEC/TiO2-OE生物纳米复合薄膜进行了抗菌和抗氧化活性评价,机械,渗透性,和接触角。显影膜对脂质氧化的影响,微生物负荷,研究了酸奶油的化学性质。制造的膜对所有测试的菌株具有抗微生物作用。含有8%OE的薄膜对脂肪氧化具有有效的保护作用,过氧化值为3.21meqO2/kg,对茴香胺值为5.40,游离脂肪酸为0.82mgKOH/kg。4%和8%OE的薄膜对酸奶油90天的微生物负荷有很好的后果。这些薄膜不会影响酸奶油的化学组成,因此可以用于此类乳制品中。
    Biodegradable edible films for sour cream packaging were developed based on chitosan (CS), hydroxyethyl cellulose (HEC), Olive leaf extract (OE), and titanium dioxide nanoparticles (TiO2-NPs). The prepared CS/HEC/TiO2-OE bionanocomposite films were evaluated for their antimicrobial and antioxidant activities as well as using FT-IR, mechanical, permeability, and contact angle. The effect of developed films on the lipid oxidation, microbiological load, and chemical properties of sour cream was investigated. The fabricated films had an antimicrobial impact against all tested strains. The film containing 8 % OE showed effective protection against fat oxidation, with a peroxide value of 3.21 meq O2/kg, a para-anisidine value 5.40, and free fatty acids of 0.82 mg KOH/kg. The films with OE 4 % and 8 % have a good effect on the microbiological load of sour cream for 90 days. These films did not influence the chemical composition of sour cream and therefore can be used in this sort of dairy product.
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  • 文章类型: Journal Article
    在追求增强食品包装,纳米技术,特别是绿色银纳米颗粒(G-AgNPs),因其卓越的抗菌性能和延长食品保质期的高潜力而备受关注。我们的研究旨在开发用G-AgNPs增强的玉米淀粉基涂层材料。使用单轴拉伸试验机检查机械性能,揭示了用最高的G-AgNPs浓度(12.75ppm)涂覆的淀粉表现出87.6MPa的UTS,与48.48MPa的对照纸相比,显著(p<0.02)增加65%。WVP的评估显示,在掺入疏水层的情况下,渗透率的统计学降低高达8%。此外,根据ISO22196:2011对抗菌性能进行了评估,证明了G-AgNPs对大肠杆菌的强和浓度依赖性活性.所有样品在两种模拟环境(土壤和海水)中都成功分解,包括呈现G-AgNPs的样品。在食品试验分析中,淀粉和G-AgNPs的存在显着减少了6天后的体重减轻,樱桃番茄减少8.59%,绿葡萄减少6.77%。这项研究的结果有助于环保包装材料的进步,与联合国减少食物浪费和促进可持续性的可持续发展目标保持一致。
    In the pursuit of enhancing food packaging, nanotechnology, particularly green silver nanoparticles (G-AgNPs), have gained prominence for its remarkable antimicrobial properties with high potential for food shelf-life extension. Our study aims to develop corn starch-based coating materials reinforced with G-AgNPs. The mechanical properties were examined using a uniaxial tensile tester, revealing that starch coated with the highest G-AgNPs concentration (12.75 ppm) exhibited UTS of 87.6 MPa compared to 48.48 MPa of control paper, a significant (p < 0.02) 65% increase. The assessment of the WVP showcased a statistical reduction in permeability by up to 8% with the incorporation of the hydrophobic layer. Furthermore, antibacterial properties were assessed following ISO 22196:2011, demonstrating a strong and concentration-dependent activity of G-AgNPs against E. coli. All samples successfully disintegrated in both simulated environments (soil and seawater), including samples presenting G-AgNPs. In the food trial analysis, the presence of starch and G-AgNPs significantly reduced weight loss after 6 days, with cherry tomatoes decreasing by 8.59% and green grapes by 6.77% only. The results of this study contribute to the advancement of environmentally friendly packaging materials, aligning with the UN sustainable development goals of reducing food waste and promoting sustainability.
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  • 文章类型: Journal Article
    天然多糖是具有巨大潜力的可再生资源之一,可替代石油衍生的化学品作为生产可生物降解膜的前体。本研究旨在使用从木薯根的外皮和皮层中提取的淀粉(木薯根加工中的废物)制备生物聚合物膜。刺槐豆半乳甘露聚糖,和纤维素纳米纤维也从木薯废料中获得。这些薄膜是通过铸造制备的,和它们的物理化学,机械,和生物降解性能进行了评价。纤维素纳米纤维的含量为0.5-2.5%。尽管添加纤维素纳米纤维并没有改变薄膜的机械性能,它显着增强了薄膜的蒸汽屏障(0.055gmm/m2hkPa-2.5%纳米纤维)及其在水性酸性和碱性介质中的稳定性。所有制备的薄膜都是可生物降解的,在五天内发生完全降解。所制备的薄膜被认为是有希望的替代品,可最大程度地减少因处置石油衍生材料而对环境造成的影响。
    Natural polysaccharides are among the renewable sources with great potential for replacing petroleum-derived chemicals as precursors to produce biodegradable films. This study aimed to prepare biopolymeric films using starch extracted from the periderm and cortex of cassava roots (waste from cassava root processing), locust bean galactomannan, and cellulose nanofibers also obtained from cassava waste. The films were prepared by casting, and their physicochemical, mechanical, and biodegradability properties were evaluated. The content of cellulose nanofibers varied from 0.5 to 2.5%. Although the addition of cellulose nanofibers did not alter the mechanical properties of the films, it significantly enhanced the vapor barrier of the films (0.055 g mm/m2 h kPa-2.5% nanofibers) and their respective stabilities in aqueous acidic and alkaline media. All prepared films were biodegradable, with complete degradation occurring within five days. The prepared films were deemed promising alternatives for minimizing environmental impacts caused by the disposal of petroleum-derived materials.
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  • 文章类型: Journal Article
    在一些应用中需要具有导电性和机械性能的生物可降解聚合物,其中由于产生的高废物而需要替代导电合成塑料。在这项研究中,生物纳米复合材料(BNCs)通过与碳纳米纤维(NPs)和改性NPs(NPs[M])使用丙烯酸等离子体进行熔融混合,通过大米淀粉的热塑性化进行复合。光谱分析,X射线衍射,和形貌进行了研究,以阐明分散和相容性对导电性和机械性能的影响。在熔融混合过程中,NPs的掺入促进了与淀粉的酯化反应,引起其晶体结构的变化。NPs[M]显示出更好的分散性和相容性,因为等离子体防止再聚集并产生更强的亲和力。BNC表现出显著的柔韧性,断裂伸长率从5.64%到248.60%,热导率从0.10增加到0.58W/mK,NPs[M]为5%。相比之下,电导率保持在相同的数量级(10-4S/cm)。淀粉-NP[M]之间更好的相容性阻碍了电子传输,但增加了声子的传播以促进热导率。本研究中通过干燥和可扩展工艺制造的BNC可能在某些应用领域引起人们的兴趣(智能食品包装,电子,纺织品,等。).
    Biodegradable polymers with conductivity and mechanical properties are required in several applications where it is necessary to substitute conductive synthetic plastics due to the high waste produced. In this study, bionanocomposites (BNCs) have been compounded by thermoplastification of rice starch via melt mixing with carbon nanofibers (NPs) and modified NPs (NPs [M]) using plasma of acrylic acid. Spectroscopy analysis, X-ray diffraction, and morphology were studied to elucidate the effect of dispersion and compatibility on the conductivity and mechanical properties. The incorporation of NPs promoted esterification reactions with starch during the melt mixing process, giving rise to changes in its crystal structure. NPs [M] showed better dispersion and compatibility because the plasma prevents reagglomeration and generates a stronger affinity. BNCs showed significative flexibility with remarked % elongation at break from 5.64 % to 248.60 %, and thermal conductivity increased from 0.10 to 0.58 W/m K, with NPs [M] at 5 %. In contrast, the electrical conductivity remained in the same magnitude order (10-4 S/cm). The better compatibility between starch-NPs [M] hinders electronic transport but increases the propagation of phonons to promote thermal conductivity. BNCs fabricated in this study by a dry and scalable process could be of interest in some application areas (intelligent food packing, electronics, textiles, etc.).
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  • 文章类型: Journal Article
    在这项研究中,我们已经开发了创新的聚合物纳米复合材料,通过整合镁-铝层状双氢氧化物(LDH)的功能分子改性的纳米载体到完全生物基聚(乳酸)/聚(丁二酸丁二醇酯-共-己二酸酯)(PLA/PBSA)基质。这些基于LDH的混合主客体系统含有生物活性化合物,如迷迭香酸,阿魏酸,和甘草次酸,以其抗氧化剂而闻名,抗菌,和抗炎特性。随着时间的推移,生物活性分子可以从纳米载体中逐渐释放,允许在各种应用中持续和受控的交付,如活性包装或化妆品。聚合物复合材料的形态分析,使用不连续机械混合器制备,揭示了聚合物界面处存在大聚集体和纳米薄片。这导致与原始共混物相比增强的水蒸气渗透性。此外,活性分子从薄膜中的迁移动力学证实了基于它们在层状系统中的固定的受控释放机制。放大实验评估了材料的形态、机械和热性能。值得注意的是,在混合过程中拉伸变形和更高的剪切速率增强了纳米载体的分散和分布,如材料的良好机械性能所证实的。
    In this study, we have developed innovative polymer nanocomposites by integrating magnesium-aluminum layered double hydroxide (LDH)-based nanocarriers modified with functional molecules into a fully biobased poly(lactic acid)/poly(butylene succinate-co-adipate) (PLA/PBSA) matrix. These LDH-based hybrid host-guest systems contain bioactive compounds like rosmarinic acid, ferulic acid, and glycyrrhetinic acid, known for their antioxidant, antimicrobial, and anti-inflammatory properties. The bioactive molecules can be gradually released from the nanocarriers over time, allowing for sustained and controlled delivery in various applications, such as active packaging or cosmetics. The morphological analysis of the polymer composites, prepared using a discontinuous mechanical mixer, revealed the presence of macroaggregates and nano-lamellae at the polymer interface. This resulted in an enhanced water vapor permeability compared to the original blend. Furthermore, the migration kinetics of active molecules from the thin films confirmed a controlled release mechanism based on their immobilization within the lamellar system. Scaling-up experiments evaluated the materials\' morphology and mechanical and thermal properties. Remarkably, stretching deformation and a higher shear rate during the mixing process enhanced the dispersion and distribution of the nanocarriers, as confirmed by the favorable mechanical properties of the materials.
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  • 文章类型: Journal Article
    食物浪费是一项紧迫的全球挑战,每年损失超过1万亿美元,占全球温室气体排放量的10%。广泛的研究已经针对使用活性生物可降解包装材料来提高食品质量,尽量减少塑料的使用,鼓励可持续包装技术发展。然而,这取得了有限的成功,这主要归因于材料性能差和生产成本高。在最近的文学中,银纳米粒子(AgNPs)的整合已显示出改善生物聚合物的性能,促进了生物纳米复合材料的发展。此外,AgNP对食源性病原体的抗菌特性导致食品保质期的改善,并提供了减少食品浪费的途径。然而,很少有评论从工业角度全面分析了整个生物聚合物组合中的AgNPs。因此,这篇综述批判性地分析了抗菌,屏障,机械,热,AgNP基生物纳米复合材料的耐水性能。这些先进的材料还在食品包装应用方面进行了讨论,并根据其在提高食品保质期方面的性能进行了评估。最后,严格讨论了AgNP生物复合材料商业化的当前障碍,以提供开发可持续包装材料以减少食物浪费的工业行动计划。
    Food waste is a pressing global challenge leading to over $1 trillion lost annually and contributing up to 10% of global greenhouse gas emissions. Extensive study has been directed toward the use of active biodegradable packaging materials to improve food quality, minimize plastic use, and encourage sustainable packaging technology development. However, this has been achieved with limited success, which can mainly be attributed to poor material properties and high production costs. In the recent literature, the integration of silver nanoparticles (AgNPs) has shown to improve the properties of biopolymer, prompting the development of bionanocomposites. Furthermore, the antibacterial properties of AgNPs against foodborne pathogens leads towards food shelf-life improvement and provides a route towards reducing food waste. However, few reviews have analyzed AgNPs holistically throughout a portfolio of biopolymers from an industrial perspective. Hence, this review critically analyses the antibacterial, barrier, mechanical, thermal, and water resistance properties of AgNP-based bionanocomposites. These advanced materials are also discussed in terms of food packaging applications and assessed in terms of their performance in enhancing food shelf-life. Finally, the current barriers towards the commercialization of AgNP bionanocomposites are critically discussed to provide an industrial action plan towards the development of sustainable packaging materials to reduce food waste.
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