chemical treatment

  • 文章类型: Journal Article
    本研究考察了超声波和三种化学单独和双重改性处理对玉米淀粉理化性质的影响,热,和流变特性。超声处理和三种化学处理破坏了淀粉颗粒,粒径减小,ζ电位显着增加。超声氧化双变性淀粉(U-O-CS)的亲水性最高,0.854g/g。超声酯化双改性淀粉(U-E-CS)的亲脂性最高,1.485g/g。超声波的糊化温度,氧化,交联改性淀粉显著增加,交联淀粉是最大的。氧化处理显着降低了淀粉的G'和G'',并削弱了质构特性。U-O-CS的流变性质进一步削弱。酯化处理后淀粉的G'下降,而G“增加了,和纹理属性被削减。交联改性获得了最大的流变和纹理性能,硬度值为284.70g。
    This study investigated the effects of ultrasonic and three chemical individual and dual modification treatments on corn starch\'s physicochemical, thermal, and rheological properties. Ultrasonication and the three chemical treatments disrupted the starch granules with a decrease in particle size and a significant increase in the ζ-potential. The hydrophilicity of ultrasonic-oxidized dual-modified starch (U-O-CS) was the highest, at 0.854 g/g. The lipophilicity of ultrasonic-esterified dual-modified starch (U-E-CS) was the highest, at 1.485 g/g. The gelatinization temperature of ultrasonic, oxidation, and cross-linking modified starches increased significantly, with cross-linking starches being the largest. Oxidative treatment significantly decreased the starch\'s G\' and G\" and weakened the textural properties. The rheological properties of U-O-CS were further weakened. The G\' of the starch decreased after the esterification treatment, while the G\" increased, and the textural properties were cut. The maximum rheological and textural properties were obtained for crosslinked modification, with a hardness value of 284.70 g.
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  • 文章类型: Journal Article
    人类不断发展的可持续需求,以生产更轻,更强硬,和更具成本效益的材料导致了生物可降解复合材料的发展。自从他们创造以来,天然纤维基复合材料无处不在。由于他们出色的表现,天然纤维增强复合材料已主要用于多种工程应用中。椰子叶鞘(CLS)是一种丰富的农业废物,可以很容易地从椰子树中提取。这篇综述研究了将椰子鞘掺入聚合物基质的潜力。此外,表面处理的效果,合成纤维杂交,和纳米填料改性的基质进行了详细分析。据观察,椰子鞘的表面改性,与其他天然或合成纤维杂交,与单块椰子鞘基聚合物复合材料相比,纳米填料改性聚合物复合材料表现出更好的机械性能。混合复合材料的关键优势之一是它们可以结合不同成分的强度以克服其各自的局限性。此外,椰子鞘基混合复合材料提高了复合材料的损伤容限,降低了材料成本。
    The ever-burgeoning sustainable need for humanity to produce lighter, tougher, and more cost-effective materials has led to the development of biodegradable composites. Ever since their creation, natural fiber-based composites have found themselves ubiquitous. Due to their exceptional performance, Natural fiber-reinforced composites have been predominantly used in several engineering applications. Coconut leaf sheath (CLS) is an abundantly available agro-waste that can be easily extracted from the coconut tree. This review investigates the potential of incorporating coconut sheath into polymeric matrices. Also, the effects of surface treatments, synthetic fiber hybridization, and nanofiller-modified matrices were analyzed in detail. It has been observed that surface modification of coconut sheath, hybridization with other natural or synthetic fibers, and nanofiller-modified polymeric composites exhibit better mechanical performance compared to monolithic coconut sheath-based polymeric composites. One of the key advantages of hybrid composites is that they can combine the strengths of different constituents to overcome their individual limitations. Moreover, coconut sheath-based hybrid composites enhance the composites\' damage tolerance and reduce the material cost.
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  • 文章类型: Journal Article
    来自食品工业的废水被认为对人体健康和水生生物有害,以及污染水和土壤。这项研究的重点是寻找一种经济实惠且易于处理食品工业产生的废物的物理化学方法。为了实现这个目标,一种新的生物基絮凝剂,称为4-苄基-4-(2-油酰胺基乙基氨基-2-氧代乙基)吗啉-4-氯化铵,使用可持续来源创建,特别是粗橄榄果渣油。它的化学结构使用各种光谱技术,如FTIR,1H-NMR,质谱,和13C-NMR。这种新的生物基阳离子絮凝剂与明矾结合,在废物处理过程中充当混凝剂。此外,进行了一项研究,以确定混凝-絮凝工艺参数的最佳条件,即,pH值和明矾用量,对COD和去除效率。结果表明,絮凝的最佳条件是在pH5.8,与680mg/L明矾和10mg/L的商业絮凝剂剂量相比,只有5mg/L的新型生物基阳离子絮凝剂。对新型生物阳离子絮凝剂和用于处理食品工业废水的商业CTAB絮凝剂进行了比较。研究发现,新型生物基阳离子絮凝剂能更有效地降低化学需氧量,与使用商业阳离子絮凝剂的54.6%相比,实现61.3%的减少。此外,使用新的生物基阳离子絮凝剂的成本仅为0.49美元/克,低于目前的阳离子絮凝剂,成本0.93美元/克。这种新型絮凝剂的采用为现有的工业废水处理工艺提供了可持续的替代方案。
    Wastewater from the food industry is considered harmful to human health and aquatic life, as well as polluting water and soil. This research is centered around finding an affordable and easy physicochemical method for dealing with waste generated by the food industry. To accomplish this goal, a new bio-based flocculant called 4-benzyl-4-(2-oleamidoethylamino-2-oxoethyl) morpholin-4-ium chloride was created using sustainable sources, specifically crude olive pomace oil. Its chemical structure was confirmed using various spectroscopic techniques such as FTIR, 1H-NMR, mass spectra, and 13C-NMR. This new bio-based cationic flocculant was combined with alum to act as a coagulant in the waste treatment process. Also, a study was conducted to determine the optimal conditions for the coagulation-flocculation process parameters, namely, pH and alum dosage, on COD and removal efficiency. The results showed that the optimal conditions for flocculation were achieved at pH 5.8, with 680 mg/L alum and 10 mg/L of commercial flocculant dose compared to only 5 mg/L of a new bio-based cationic flocculant. A comparison was made between the new bio-cationic flocculant and a commercial CTAB one for treating wastewater in the food industry. The study found that the new bio-based cationic flocculant was more effective in reducing the chemical oxygen demand, achieving a reduction of 61.3% compared to 54.6% for using a commercial cationic flocculant. Furthermore, using a new bio-based cationic flocculant costs only 0.49 $/g, which is less than the present cationic flocculant, which costs 0.93 $/g. The adoption of this new flocculant provides a sustainable alternative to existing industrial wastewater treatment processes.
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  • 文章类型: Journal Article
    酒糟(BSG)是酿酒行业的主要副产品,占啤酒生产过程中产生的总废物的85%。这种木质纤维素材料传统上用作家畜饲料并以低价出售。然而,BSG可用作生产生物活性分子和化学品前体的低成本原料,提升这种副产品的价值。在这种情况下,BSG是用于提取抗氧化剂如阿魏酸(FA)和对香豆酸(p-Cu)的有前途的原料。评估了三种水解处理从BSG中提取FA和p-Cu的有效性,即酶(基于阿魏酸酯酶和内切-1,4-β-木聚糖酶之间的协同合作),碱性和热液。水热处理产生了最高的提取率(FA和p-Cu的7.2g/kgBSG和1.4g/kgBSG,分别)在较短的提取时间(一小时)内。另一方面,在25°C孵育4小时内,酶水解提取了4.3g/kgBSG的FA,p-Cu的产量可忽略不计。在120°C下碱处理超过5小时,FA的产率为5.5g/kgBSG,p-Cu的产率为0.6g/kgBSG。质量和能量平衡表明,操作成本对提取过程中使用的BSG浓度的高度依赖性。费用为34.5欧元,该化学品每公斤FA为6607欧元和205.5欧元,100kgBSG/m3的酶和水热萃取方法。
    Brewers\' spent grain (BSG) is the main byproduct from the brewing industry, which accounts for 85 % of the total waste generated during beer production. This lignocellulosic material is traditionally used as livestock feed and sold at a low price. However, BSG can be used as a low-cost feedstock for the production of bioactive molecules and chemicals precursors, upgrading the value of this byproduct. In this context, BSG is a promising feedstock for the extraction of antioxidants like ferulic acid (FA) and p-coumaric acid (p-Cu). The effectiveness of three hydrolysis treatments were evaluated for the extraction of FA and p-Cu from BSG, namely enzymatic (based on the synergistic cooperation between a feruloyl esterase and an endo-1,4-β-xylanase), alkaline and hydrothermal. The hydrothermal treatment produced the highest extraction yields (7.2 g/kgBSG and 1.4 g/kgBSG for FA and p-Cu, respectively) in a short extraction time (an hour). On the other hand, enzymatic hydrolysis extracted 4.3 g/kgBSG for FA and negligible yields for p-Cu in 4 h of incubation at 25 °C. Yields of 5.5 g/kgBSG for FA and 0.6 g/kgBSG for p-Cu were obtained in more than 5 h of alkaline treatment at 120 °C. The mass and energy balances revealed the high dependence of the operating costs on the concentration of BSG used during the extraction process, with costs of 34.5 €, 6607 € and 205.5 € per kg of FA for the chemical, enzymatic and hydrothermal extraction methods at 100 kg BSG/m3.
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  • 文章类型: Journal Article
    义齿骨折是牙科实践中常见的问题,它们的修复被认为是恢复其功能属性的第一选择。然而,材料间电阻可能会受损。通常,这些材料之间的结合减弱。因此,可以考虑各种表面处理方法来增强它们的机械性能。使用聚(甲基丙烯酸甲酯)(PMMA)热聚合树脂(HPR)作为修复材料,用于维修的冷聚合材料(CPR),和不同变体的氧化铝磨料喷砂(AB),甲基丙烯酸甲酯(M),乙酸乙酯(EA),二氯甲烷(CH),应用异丙醇(IA)处理。最后,选择并分析了组合表面处理。通过扫描电子显微镜和弯曲观察处理后的表面形貌,剪力,和冲击强度进行了测试。AB和CH化学处理,M,EA被用来改善所有的机械性能,并且通过结合两种类型的处理可以实现性能的进一步改善。观察到表面形态的变化。由于冲击强度低,用IA处理产生不太有利的结果。AB和CH的组合取得了最好的结果,但是在应用CH期间,必须严格控制暴露时间。
    Denture fractures are a common problem in dental practice, and their repair is considered a first option to restore their functional properties. However, the inter-material resistance may become compromised. Typically, the bond between these materials weakens. Therefore, various surface treatment methods may be considered to enhance their mechanical properties. Poly(methyl methacrylate) (PMMA) heat-polymerized resin (HPR) was used as the repaired material, cold-polymerized material (CPR) for the repairs, and different variants of alumina abrasive blasting (AB), methyl methacrylate (M), ethyl acetate (EA), methylene chloride (CH), and isopropyl alcohol (IA) treatments were applied. Finally, combined surface treatments were chosen and analyzed. Surface morphologies after treatments were observed by scanning electron microscopy and the flexural, shear, and impact strengths were tested. AB and chemical treatment with CH, M, and EA was used to improve all mechanical properties, and further improvement of the properties could be achieved by combining both types of treatments. Varied changes in surface morphologies were observed. Treatment with IA yielded less favorable results due to the low impact strength. The best results were achieved for the combination of AB and CH, but during the application of CH it was necessary to strictly control the exposure time.
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  • 文章类型: Journal Article
    当前对用可再生纤维增强的复合材料的需求比以往任何时候都要大。与玻璃纤维相比,天然纤维具有密度和成本较低的优点。尽管玻璃和天然纤维之间存在相当的特定特性,后者显示出较低的强度。然而,与铜涂层和天然纤维的化学处理,现在可以增加复合材料的强度。当前的研究调查集中在原始的生命周期评估,经过化学处理,和铜涂层纤维增强甘蔗渣和香蕉复合材料,以比较这些样品对环境的排放,以证明其适用性。这项研究包括所有的过程,从纤维的提取到复合材料的形成,即,从摇篮到大门,和详细的库存。ReCiPeH中点法已在SimaPro软件中用于量化排放。结果表明,最大的全球变暖排放是由于这些复合材料制造过程中使用的能源消耗。在全球变暖的贡献中,化学处理和铜涂层复合材料的电力贡献略大于原始复合材料的电力贡献,即C-BG/P中的73.275%,73.06%的Cu-BG/P,C-BN/P为73.65%,Cu-BN/P为74.28%,相对高于R-BG/P为63.8%,R-BN/P为64.97%。下一个主要贡献来自聚乳酸的所有三个样品的甘蔗渣纤维增强的PLA复合材料和香蕉纤维增强的PLA复合材料。与化学和铜涂覆的样品相比,原始样品还显示出改善的纤维强度。
    The current demand for composites reinforced with renewable fibers is greater than it has ever been. In comparison to glass fibers, natural fibers yield the advantages of lesser density and cost. Although comparable specific properties exist between glass and natural fibers, the latter shows lower strength. However, with the copper coating and chemical treatment of natural fibers, the strength of the composites can be increased nowadays. The current research investigation focuses on the life cycle assessment of the raw, chemically treated, and copper coated fiber reinforced bagasse and banana composites to compare the emissions on the environment of these samples to prove their applicability. The study includes all the processes, from the extraction of fibers to the formation of composites, i.e., from cradle to gate, and detailed inventory. The ReCiPe H midpoint method has been utilized in SimaPro software to quantify the emissions. The results indicate that the maximum global warming emission is due to the energy consumption used during the manufacturing of these composites. Electricity contribution for chemically treated and copper coated composites in global warming contribution is slightly greater than that of raw composites i.e., 73.275 % in C- BG/P, 73.06 % in Cu- BG/P, 73.65 % in C- BN/P and 74.28 % in Cu- BN/P which is comparatively higher than 63.8 % in R- BG/P and 64.97 % in R- BN/P. The next major contributions come from polylactic acid for all the three samples of bagasse fiber reinforced PLA composite and banana fiber reinforced PLA composite. The raw samples also show improved fiber strength compared to chemical and copper coated samples.
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  • 文章类型: Journal Article
    采用不同的化学处理方法对棉秆纤维进行表面改性,然后用作复合材料中的填料。使用熔融共混技术将这些处理过的纤维掺入聚乳酸/聚丙烯熔融共混物中。结果表明,增加棉秆纤维的表面粗糙度可以提高复合材料的整体力学性能。尽管可能导致较差的纤维-基质相容性。相反,发现光滑的纤维表面可以改善与聚乳酸的相容性,而Si-O-C硅烷涂层增加了纤维的规律性和与基体的界面相互作用,从而提高耐热性。由碱/硅烷处理的纤维制成的复合材料的机械性能和热稳定性表现出最显著的改善。此外,纤维在基体中更好的分散和更规则的纤维取向有利于提高复合材料的整体结晶度。然而,这种纤维分布不利于增强抗冲击性,虽然这个缺点可以通过增加增强纤维的表面粗糙度来减轻。
    Different chemical treatment methods were employed to modify the surface of cotton stalk fibers, which were then utilized as fillers in composite materials. These treated fibers were incorporated into polylactic acid/polypropylene melt blends using the melt blending technique. Results indicated that increasing the surface roughness of cotton stalk fibers could enhance the overall mechanical properties of the composite materials, albeit potentially leading to poor fiber-matrix compatibility. Conversely, a smooth fiber surface was found to improve compatibility with polylactic acid, while Si-O-C silane coating increased fiber regularity and interfacial interaction with the matrix, thereby enhancing heat resistance. The mechanical properties and thermal stability of the composite materials made from alkali/silane-treated fibers exhibited the most significant improvement. Furthermore, better dispersion of fibers in the matrix and more regular fiber orientation were conducive to increasing the overall crystallinity of the composite materials. However, such fiber distribution was not favorable for enhancing impact resistance, although this drawback could be mitigated by increasing the surface roughness of the reinforcing fibers.
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  • 文章类型: Journal Article
    亚洲clamCorbiculafluminea是东亚和非洲的本地水生物种,但已成为欧洲水生生态系统中对生态和经济有害的入侵物种之一,北美,和南美洲。由于它们作为雌雄同体物种具有高繁殖力和扩散能力的自然特征,亚洲蛤仔一旦渗入水体,就极难根除。这是美国东北部各州的一个新问题,由于气候变化,亚洲蛤仔将其范围扩大到更远的北方。已经进行了广泛的研究以开发用于反应性控制侵袭性软体动物种群并主动防止其进一步传播的化学治疗方法。然而,治疗主要针对工业环境中的生物污染双壳类动物。对自然开放水系统中使用的亚洲蛤类化学处理进行了全面审查,以评估杀软体动物剂,并确定新兴处理的毒性范围,这些处理可最大程度地提高亚洲蛤类死亡率,并最大程度地减少对水质和非目标物种的负面影响。本报告总结了亚洲蛤类控制和管理中潜在的化学应用,以协助资源管理者和从业人员进行侵入性亚洲蛤类管理。
    The Asian clam Corbicula fluminea is a native aquatic species in Eastern Asia and Africa but has become one of the ecologically and economically harmful invasive species in aquatic ecosystems in Europe, North America, and South America. Due to their natural characteristics as a hermaphroditic species with a high fecundity and dispersal capacity, Asian clams are extremely difficult to eradicate once they have infiltrated a waterbody. This is an emerging issue for states in the Northeastern United States, as Asian clams expand their range farther North due to climate change. There has been extensive research conducted to develop chemical treatments for reactively controlling invasive mollusc populations and proactively preventing their further spread. However, treatments are mostly targeted toward biofouling bivalves in industrial settings. A comprehensive review of Asian clam chemical treatments used in natural open-water systems was performed to evaluate molluscicides and identify the toxicity ranges of emerging treatments that maximize Asian clam mortality and minimize the negative impact on water quality and non-target species. The potential chemical applications in Asian clam control and management are summarized in this report to assist resource managers and practitioners in invasive Asian clam management.
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  • 文章类型: Journal Article
    了解植物细胞壁内聚合物的分布和可及性对于解决木质纤维素材料中的生物质不顺应性至关重要。在这项工作中,成像傅里叶变换红外(FTIR)和拉曼光谱,加上有针对性的化学治疗,用于研究两种竹种在组织和细胞壁水平上的细胞壁聚合物分布。组织水平成像FTIR显示,纤维鞘和纤维束之间细胞壁聚合物的分布和化学活性存在显着差异。在细胞壁水平,成像拉曼光谱描绘了次生壁和细胞间层之间的明显差异,后者含有较高水平的木质素,羟基肉桂酸(HCA),还有木聚糖,和较低的纤维素。温和的酸化亚氯酸钠处理导致木质素的部分去除,HCA,和来自细胞间层的木聚糖,尽管程度低于碱性处理,表明这些聚合物对化学处理的敏感性。相比之下,木质素在次生壁表现出有限的反应性酸化亚氯酸钠,但被轻微的碱处理去除,表明化学性质稳定,有轻微的碱性不耐受。这些发现为植物细胞的固有设计机制及其有效利用提供了有价值的见解。
    Understanding the distribution and accessibility of polymers within plant cell walls is crucial for addressing biomass recalcitrance in lignocellulosic materials. In this work, Imaging Fourier Transform Infrared (FTIR) and Raman spectroscopy, coupled with targeted chemical treatments, were employed to investigate cell wall polymer distribution in two bamboo species at both tissue and cell wall levels. Tissue-level Imaging FTIR revealed significant disparities in the distribution and chemical activity of cell wall polymers between the fibrous sheath and fibrous strand. At the cell wall level, Imaging Raman spectroscopy delineated a distinct difference between the secondary wall and intercellular layer, with the latter containing higher levels of lignin, hydroxycinnamic acid (HCA), and xylan, and lower cellulose. Mild acidified sodium chlorite treatment led to partial removal of lignin, HCA, and xylan from the intercellular layer, albeit to a lesser extent than alkaline treatment, indicating susceptibility of these polymers to chemical treatment. In contrast, lignin in the secondary wall exhibited limited reactivity to acidified sodium chlorite but was slightly removed by alkaline treatment, suggesting stable chemical properties with slight alkaline intolerance. These findings provide valuable insights into the inherent design mechanism of plant cells and their efficient utilization.
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  • 文章类型: Journal Article
    巴基斯坦是一个生产大量水果的农业国家,喜欢:芒果,香蕉,苹果,桃子,葡萄,李子,各种柑橘类水果,包括柠檬,葡萄柚,还有橘子.到目前为止,大多数水果的果皮通常都被浪费掉了,没有在任何地方得到适当的利用。在这项工作中,在受控的空气供应下,通过缓慢热解将香蕉和葡萄柚的果皮转化为生物炭,并在用ZnCl2和十二烷基硫酸钠(SDS)进行化学改性后,用于从水性介质中螯合氰根离子。通过各种仪器技术对改性生物炭进行了表征,喜欢:SEM,FTIR,TGA,和CHNS。不同的参数,喜欢:时间,温度,pH值,和影响氰离子吸附的吸附剂剂量,对制备的生物炭进行了优化,并了解了吸附现象,进行了动力学和热力学研究。通过使用标准离子选择电极系统估算氰根离子的浓度,发现十二烷基硫酸钠处理过的香蕉皮生物炭显示出更多的吸附能力,即,与所有样品相比:17.080mg/g。目前的工作表明,从水果废物产生的生物炭具有足够的潜力,以消除水中的痕量氰化物,特别是用十二烷基硫酸钠处理后。
    亚洲和非洲国家的一个工业区使用传统技术进行采矿是废水中氰化物毒性的主要原因。所以,在这里,由香蕉和葡萄果皮制成的化学制造的生物炭用于去除氰离子,以绿色方式利用当地资源控制水生污染。良好的结果表明了该工艺的可行性,这是成本有效的,方便,生态友好,和可持续的。
    Pakistan is an agricultural country producing plenty of fruits, like: mango, banana, apple, peaches, grapes, plums, variety of citrus fruits including lemon, grapefruit, and oranges. So far the peels of most of the fruits are usually wasted and not properly utilized anywhere. In this work, the peels of banana and grapefruit are converted into biochar by slow pyrolysis under controlled supply of air and used for sequestering cyanide ions from aqueous medium after chemical modification with ZnCl2 and sodium dodecyl sulfate (SDS). The modified biochar was characterized by various instrumental techniques, like: SEM, FTIR, TGA, and CHNS. Different parameters, like: time, temperature, pH, and dose of adsorbent affecting the adsorption of cyanide ions, onto prepared biochar were optimized and to understand the adsorption phenomenon, kinetic and thermodynamic studies were performed. Concentration of cyanide ions was estimated by employing standard ion selective electrode system and it is found that Sodium Dodecyl Sulfate treated biochar of banana peels shown more adsorption capacity, i.e.,: 17.080 mg/g as compared to all samples. Present work revealed that the biochar produced from the fruit waste has sufficient potential to eliminate trace quantities of cyanide from water, especially after treatment with sodium dodecyl sulfate.
    An industrial area in Asian and African countries where mining is done using traditional techniques is the major cause of cyanide toxicity in wastewater streams. So, here chemically fabricated biochar made by peels of banana and grape fruit is employed for removal of cyanide ion for controlling aquatic pollution using local resources in green way. Favorable results indicated the feasibility of this process, which is cost effective, convenient, ecofriendly, and sustainable.
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