•The LS stems contain a large number of fiber cells aligned and bounded together.•ATR–FTIR and X-ray analysis confirmed that the LS fibers are rich in cellulose.•TGA analysis indicated that the LS ...fibers are thermally stable until 220°C.•LS fibers show a good mechanical characteristics compared to other cellulosic fibers.•This research qualify LS fiber as potential reinforcement in composite materials.
Integration of new natural fibers in polymer composites field can contribute to increase the production of natural reinforcements and expand their use into new applications. In the present work, new cellulosic fibers were extracted from Lygeum spartum L. plant using an eco-friendly method. The morphological, physico-chemical, thermal and mechanical properties of L. spartum L. fibers were reported for the first time in this paper. The stem anatomy and fiber SEM micrographs showed a strong presence of fiber cells. ATR–FTIR and X-ray analysis proved that these fibers are rich in cellulose content with crystallinity index of 46.19%. The thermogravimetric analysis indicates that the L. spartum fibers are thermally stable until 220°C with apparent activation energy of 68.77kJ/mol. Young's modulus, tensile strength and strain at failure were determined from the single fiber tensile test as 13.2GPa, 280MPa, and 3.7% respectively.
•Microplastics were identified in seven intertidal mangrove habitats of Singapore.•Majority of microplastics identified were fibrous and less than 20μm.•Polyethylene, polypropylene, nylon and PVC ...were identified using ATR–FTIR.
The prevalence of microplastics was studied in seven intertidal mangroves habitats of Singapore. Microplastics were extracted from mangrove sediments via a floatation method, and then counted and categorized according to particle shape and size. Representative microplastics from Berlayar Creek, Sungei Buloh, Pasir Ris and Lim Chu Kang were isolated for polymer identification using Attenuated Total Reflectance–Fourier Transform Infrared (ATR–FTIR) spectroscopy. Microplastics were identified in all seven habitats, with the highest concentration found in sediments at Lim Chu Kang in the northwest of Singapore. The majority of microplastics were fibrous and smaller than 20μm. A total of four polymer types were identified, including polyethylene, polypropylene, nylon and polyvinyl chloride. The relationship between abundance of microplastics and sediment grain size was also investigated, but no relationship was apparent. The presence of microplastics is likely due to the degradation of marine plastic debris accumulating in the mangroves.
The objective of this research was to screen and isolate fucoidan from Malaysian seaweeds and subsequently determine its antioxidant capacity. A screening test employing a colorimetric method was ...conducted on five types of Malaysian brown and red seaweeds. It was found that Sargassum binderi contained the highest fucoidan content (6.16 ± 0.08%). Thus, fucoidan was isolated from S. binderi (yield 7.5%, purity 89.63%) for the determination of its antioxidant capacity. The isolated fucoidan was identified using high performance anion exchange chromatography (HPAEC) and attenuated total reflectance Fourier transform infra-red (ATR-FTIR) spectroscopy. The antioxidant assays performed were total phenolic content (TPC), free-radical scavenging activity (DPPH), reducing power, superoxide anion scavenging activity (SOA) and hydroxyl radical scavenging activity (OH). The antioxidant capacity of the extracted fucoidan (Fsar) was compared with those of a commercial food-grade fucoidan (Fysk) and of BHA, BHT and ascorbic acid. All the antioxidant assays performed showed either Fsar has significantly higher (p < 0.05) or do not differ significantly (p > 0.05) in activities compared to that of Fysk. At the same time, both Fsar and Fysk showed significant (p < 0.05) antioxidant capacity in terms of superoxide anion and hydroxyl radical scavenging activities compared to those of the synthetic antioxidants. This shows that Fsar has the potential to be commercialised as a functional food product or as bioingredients with high antioxidative properties.
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•Fucoidan was highest in Sargassum binderi among 5 seaweed species screened.•HPLC and FTIR results confirmed that the compound extracted was fucoidan.•Purity of the extracted fucoidan was 89.63%.•Fucoidan isolated from S. binderi has significant secondary antioxidant potential.•Both isolated and commercial food-grade fucoidan has comparable antioxidant capacity.
Aquatic ecosystems are globally contaminated with microplastics (MP). However, comparative data on MP levels in freshwater systems is still scarce. Therefore, the aim of this study is to quantify MP ...abundance in water and sediment of the German river Elbe using visual, spectroscopic (Fourier-transform infrared spectroscopy) and thermo analytical (pyrolysis gas chromatography mass spectrometry) methods. Samples from eleven German sites along the German part of the Elbe were collected, both in the water and sediment phase, in order to better understand MP sinks and transport mechanisms. MP concentrations differed between the water and sediment phase. Sediment concentrations (mean: 3,350,000 particles m−3, 125–5000 μm MP) were in average 600,000-fold higher than water concentrations (mean: 5.57 particles m−3, 150–5000 μm MP). The abundance varied between the sampling sites: In sediments, the abundance decreased in the course of the river while in water samples no such clear trend was observed. This may be explained by a barrage retaining sediments and limiting tidal influence in the upstream parts of the river. Particle shape differed site-specifically with one site having exceptionally high quantities of spheres, most probably due to industrial emissions of PS-DVB resin beads. Suspended MP consisted predominantly of polyethylene and polypropylene whereas sediments contained a higher diversity of polymer types. Determined MP concentrations correspond well to previous results from other European rivers. In a global context, MP levels in the Elbe relate to the lower (water) to middle section (sediment) of the global range of MP concentrations determined for rivers worldwide. This highlights that elevated MP levels are not only found in single countries or continents, but that MP pollution is an issue of global concern.
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•Low to medium microplastic (MP) levels in the river Elbe•Much higher MP abundance in sediments compared to the water phase•Decreasing levels of MP in sediments over the course of the river•Higher polymer diversity in sediments compared to the water phase•Industrial emissions possibly caused MP hotspots
PEO/PVA blends have been prepared to investigate the effect of gamma rays on the structural, morphological and photoluminescence properties. The studies of non-irradiated and irradiated samples with ...radiation doses of 10 kGy were examined by using XRD, ATR-FTIR, Optical microscopy and PL. Gamma photons induced important chemical rearrangements, especially by PVA hydroxyl groups. We found that the crystallinity rate is strongly influenced by radiation. In this context, one could predict that the immiscibility of PVA with PEO and the interactions between the chains are of the electrostatic type. A structural-scale disturbance due to the radical formation leads to spherulitic texture modifications of the PEO. Due to the luminescence properties, the blend samples behave like core-shell nanoparticles. This phenomenon is due to the fact that the PVA polymer played the role of shell. Irradiation makes it possible to obtain well-ordered spherulites and to get a high pore density. The irradiated blend showed a higher quantum yield. The significant chemical and morphological changes caused by gamma radiation favored the optical recombination of hydroxyl groups.
Organic fertilizers have become a vector for the transport of microplastics (MPs), which pose human health concerns through the food chain. This study aimed to quantify and characterize MPs in eight ...different compost samples of various raw materials and their subsequent translocation to lettuce (Lacuta sativa) grown on contaminated composts. The results revealed that the MP abundance ranged from 3810 to 16530 MP/kg. Municipal solid waste compost (MSWC) had highest abundance (16082 ± 632 MP/kg), followed by leaf compost (LC) and organic compost (OC) (6299 ± 1011 and 3680 ± 419 MP/kg, respectively). MPs of <100 μm in size were most dominant in MSWC and LC. Fragments and fibers were the prevalent shape types, with white/transparent colored MPs being more abundant. Polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) were the dominant polymers. MPs accumulation in the lettuce leaves was greatest in the lettuce plants grown on MSWC, followed by those grown on LC and OC, indicating that MSWC grown lettuce is not suitable for human consumption. The decrease in the growth (leaf length, number of leaves, leaf fresh and weights) and physiological (membrane stability index, relative water contents) parameters of lettuce was in line with the trend of MP accumulations. Hence, it is highly important to regulate the plastic contents in compost because it is a threat to ecosystems and human health.
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•Microplastics abundance in three compost types (organic, leaf, MSW) was analyzed.•Size <100 μm microplastics dominated in MSW compost and leaf compost.•Microplastics of shape (fragment, fiber), color (white), polymer (PP) dominated.•Lettuce leaves accumulated microplastics depending on their abundance in composts.
Authentic representative gum exudate samples from Acacia species namely Acacia senegal var. senegal (ASG), Acacia mellifera (AMF), Acacia seyal var. seyal (ASY), and Acacia tortilis var. raddiana ...(ATR), were physicochemically analyzed. The moisture, ash, nitrogen and protein content, pH, specific optical rotation, and number average molecular weight were found to be ranging from 9.76% to 8.35%, 3.40% to 2.05%, 0.243% to 1.549%, 1.610% to 10.378%, 4.45 to 4.94, −48.25 to +86.75 and 0.24×106 to 2.95×106 respectively. The 13C and 1H NMR spectra of gum samples showed similarity in individual sugar components, but characteristic patterns of each gum, were observed. FTIR spectra of the studied gums show the presence of the same functional groups in the four gums. DSC and TGA thermograms were characteristic for each gum. Evaluation of the functional properties of the four gums indicated that ATR gum bears the best emulsification characteristics in terms of emulsion’s stability and emulsification power.
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•The CuxCey catalysts were synthesized using a hydrothermal and carbonization two-step method.•The morphology and Ov of CuxCey catalysts can be manipulate by the amount of metal ...salts.•The dual effects of morphology and Ov influence product distribution in ECR.•The possible reaction pathway was monitor by ATR-FTIR.
Despite significant advancements in the investigation of catalyst morphology in electrochemical CO2 reduction (ECR), achieving precise control over multi-carbon (C2+) products selectivity remains challenging. Thus, a sequence of catalysts with incorporation of CuO onto three-dimensional (3D) spherical CeO2 were synthesized using a hydrothermal and calcination two-step method. The molar ratios of Cu(NO3)2·H2O to Ce(NO3)3·6H2O can manipulate morphology and oxygen vacancies (Ov) of CuxCey catalysts, further influencing their product distribution in ECR. Materials characterization and electrochemical testing demonstrate that dual effects of spherical morphology and Ov in the CuxCey catalysts can enhance the activity and C2H4 selectivity in ECR. To elaborate further on the topic, the pure CeO2 exhibits excellent Faradaic efficiency (FE) of CH4 with the value of 54.3 %. Cu7Ce3, among all CuxCey catalysts, reaches a maximum value of 37.22 % at −1.2 V vs. RHE, possibly attributed to its highest Ov concentration. More significantly, the possible reaction pathway was monitor by ATR-FTIR technique for CuxCey during ECR is: CO2 → *COOH →*CO → *CHO → *OCCOH → C2H4. The concept of dual tuning strategy by morphology and Ov opens up a wide range of possibilities for the development of effective Cu-based catalysts for ECR.
•ATR–FTIR could be used to determine if sample contains any type of gelatin.•ATR–FTIR could be used to differentiate gelatin samples considering sources.•ATR–FTIR is simpler and less expensive method ...when comparing with other methods.•ATR–FTIR could be used for rapid determination of gelatin source.
The objective of this research was to develop a rapid spectroscopic technique as an alternative method for the differentiation and authentication of gelatin sources in food products by using attenuated total reflectance Fourier transform infrared (ATR–FTIR) spectra combined with chemometrics. Clear discrimination and classification of all the studied gelatin sources (bovine, porcine, and fish) were achieved by hierarchical cluster and principle component analysis (PCA). Amide-I (1700–1600cm−1) and Amide-II (1565–1520cm−1) spectral bands were used in a chemometric method. Moreover, ATR–FTIR spectral data successfully discriminated pure bovine gelatin from mixture of bovine and porcine gelatins, which is very important for the food industry. The method that we adopted could be beneficial for rapid, simple and economic determination of both gelatin presence and its origin from food products such as yogurt, ice cream, milk dessert or other gelatin containing products such as pharmaceuticals and cosmetics.
Zein fibres loaded with fish oil were generated by electrospinning of zein polymer solutions (20% w/w) prepared in 70% (w/w) aqueous ethanol and isopropanol solvents. Zein fibres with a diameter of ...about 300nm with smooth surface morphology were produced from ethanol-based solutions. The fibre diameter increased to about 500nm as a result of the addition of 30% (w/w) fish oil. Thinner fibres (190±62nm) with beads averaging up to 1μm in size were produced from isopropanol zein solutions with decreasing bead formation due to the addition of fish oil by 30% (w/w). Transmission electron microscopy and florescence microscopy were utilized to examine the distribution of fish oil in the electrospun materials, revealing that the lipid phase tended to concentrate at the core of the fibres and beads, as a result of phase separation during the electrospinning process. This behaviour positively impacted the encapsulation efficiency, loading capacity, as well as the stability of the fish oil tested at 4, 25 and 60°C. The encapsulation efficiency of the electrospun zein fibres reached as high as 91% for ethanol-based and 96% for isopropanol-based fibres, at 30% (w/w) loading level. The oxidative stability of the encapsulated and non-encapsulated fish oil was monitored over a period of 14days by determining the formation of lipid peroxide using a modified ferrous oxidation–xylenol orange method. The secondary oxidative by-products were evaluated by p-anisidine value. The oxidative stability was further monitored via Fourier transform infrared spectroscopy. The results indicated that electrospun zein fibres provide a greater oxidative stability in comparison to non-encapsulated fish oil.
•ω-3 rich fish oil was encapsulated in zein fibre using an electrospinning technique.•Fibres were analysed with SEM, TEM and fluorescent microscopy.•Encapsulation efficiency was higher than conventional methods.•Oxidative stability of fish oil was enhanced after encapsulation.•Fish oil degradation was studied using FTIR.
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