Poly[R-3-hydroxybutyrate-co-(R-3-hydroxyvalerate)] (PHBVs) copolymers are promising biopolymers, which could substitute petroleum-based plastics for various applications. PHB and PHBV pellets were processed on a custo...Poly[R-3-hydroxybutyrate-co-(R-3-hydroxyvalerate)] (PHBVs) copolymers are promising biopolymers, which could substitute petroleum-based plastics for various applications. PHB and PHBV pellets were processed on a customized 3D printer via Fused Granular Manufacturing (FGM) approach modified with a Mahor screw extruder. To anticipate the behaviour of PHBVs when transformed using conventional thermo-mechanical shaping processes, thermal and mechanical analyses were carried out in order to better understand the effect of annealing temperature on their crystallization behaviour and mechanical properties of PHB polymer and PHBV copolymer. The objectives of the present work were to propose an experimental strategy to study the melting and crystallization events, crystalline structure changes, and mechanical performances of both PHB homopolymer and PHBV copolymer according to identical thermal annealing treatments. A monitoring of 3D printed PHB and PHBV structures was achieved by coupling Differential Scanning Calorimetry (DSC) and tensile tests. .展开更多
The miscibility and crystallization of solution casting biodegradable poly(3-hydroxybuty- rate)/poly(ethylene succinate) (PHB/PES) blends was investigated by differential scanning calorimetry, rheology, and opti...The miscibility and crystallization of solution casting biodegradable poly(3-hydroxybuty- rate)/poly(ethylene succinate) (PHB/PES) blends was investigated by differential scanning calorimetry, rheology, and optical microscopy. The blends showed two glass transition temperatures and a depression of melting temperature of PHB with compositions in phase diagram, which indicated that the blend was partially miscible. The morphology observation supported this result. It was found that the PHB and PES can crystallize simultaneously or upon stepwise depending on the crystallization temperatures and compositions. The spherulite growth rate of PHB increased with increasing of PES content. The influence of compositions on the spherulitic growth rate for the partially miscible polymer blends was discussed.展开更多
Poly-3-hydroxybutyrate (PHB) can be produced by various species of bacteria. Among the possible carbon sources, both methane and methanol could be a suitable substrate for the production of PHB. Methane is cheap and...Poly-3-hydroxybutyrate (PHB) can be produced by various species of bacteria. Among the possible carbon sources, both methane and methanol could be a suitable substrate for the production of PHB. Methane is cheap and plentiful not only as natural gas, but also as biogas. Methanol can also maintain methanotrophic activity in some conditions. The methanotrophic strain Methylosinus trichosporium IMV3011 can accumulate PHB with methane and methanol in a brief nonsterile process. Liquid methanol (0.1%) was added to improve the oxidization of methane. The studies were carried out using shake flasks. Cultivation was performed in two stages: a continuous growth phase and a PHB accumulation phase under the conditions short of essential nutrients (ammonium, nitrate, phosphorus, copper, iron (Ⅲ), magnesium or ethylenediamine tetraacetate (EDTA)) in batch culture. It was found that the most suitable growth time for the cell is 144 h. Then an optimized culture condition for second stage was determined, in which the PHB concentration could be much increased to 0.6 g/L. In order to increase PHB content, citric acid was added as an inhibitor of tricarboxylic acid cycle (TCA). It was found that citric acid is favorable for the PHB accumulation, and the PHB yield was increased to 40% (w/w) from the initial yield of 12% (w/w) after nutrient deficiency cultivation. The PHB produced is of very high quality with molecular weight up to 1.5 × 10^6Da.展开更多
AIM: To establish the potential of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) as a material for tendon repair. METHODS: The biocompatibility of PHBHHx with both rat tenocytes (rT) and human mesenchymal ste...AIM: To establish the potential of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) as a material for tendon repair. METHODS: The biocompatibility of PHBHHx with both rat tenocytes (rT) and human mesenchymal stem cells (hMSC) was explored by monitoring adhesive characteristics on films of varying weight/volume ratios coupled to a culture atmosphere of either 21% O2 (air) or 2% O2 (physiological normoxia). The diameter and stiffness of PHBHHx films was established using optical coherence tomography and mechanical testing, respectively. RESULTS: Film thickness correlated directly with weight/volume PHBHHx (r2 = 0.9473) ranging from 0.1 mm (0.8% weight/volume) to 0.19 mm (2.4% weight/volume). Film stiffness on the other hand displayed a biphasic response which increased rapidly at values > 1.6% weight/volume. Optimal cell attachment of rT required films of ≥ 1.6% and ≥ 2.0% weight/volume PHBHHx in 2% O2 and 21% O2 respectively. A qualitative adhesion increase was noted for hMSC in films ≥ 1.2% weight/volume, becoming significant at 2% weight/volume in 2% O2. An increase in cell adhesion was also noted with ≥ 2% weight/volume PHBHHx in 21% O2. Cell migration into films was not observed. CONCLUSION: This evaluation demonstrates that PHBHHx is a suitable polymer for future cell/polymer replacement strategies in tendon repair.展开更多
Poly(3-hydroxybutyrate) (PHB) is an intracellular carbon and energy storage material accumulated by many kinds of microorganism under unfavorable growth conditions. For the production of PHB, Alcaligenes eutrophus has...Poly(3-hydroxybutyrate) (PHB) is an intracellular carbon and energy storage material accumulated by many kinds of microorganism under unfavorable growth conditions. For the production of PHB, Alcaligenes eutrophus has been widely used because it is easy to grow, and its physiological and biochemical changes during the PHB synthesis is understood in details. A very high concentration and productivity of PHB could be obtained by fed-batch culture of Alcaligenes eutrophus with phosphate limitation in 50 L fermenter.展开更多
Biosynthesis and thermal properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with different HV (hydrovalerate) content produced by a Bacillus cereus strain were investigated. A large variety of HV ...Biosynthesis and thermal properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with different HV (hydrovalerate) content produced by a Bacillus cereus strain were investigated. A large variety of HV contents (up to about 90 mol%) of PHBV could be produced by this strain. Combined nitrogen sources containing both yeast extract and ammonium sulphate were better for cell growth and polyhydroxyalkanoates (PHA) production than either yeast extract or ammonium sulphate alone. Propionic acid is more favorable for the production of HV content than that of valeric acid. Finally, thermal properties of PHBV produced by this strain are found close to the results of other groups.展开更多
Tissue engineered scaffold is one of the hopeful therapies for the patients with organ or tissue damages. The key element for a tissue engineered scaffold material is high biocompatibility. Herein the poly (3-hydroxyb...Tissue engineered scaffold is one of the hopeful therapies for the patients with organ or tissue damages. The key element for a tissue engineered scaffold material is high biocompatibility. Herein the poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) film was irradiated by the low temperature atmospheric plasma and then coated by the silk fibroins (SF). After plasma treatment, the surface of PHBHHx film became rougher and more hydrophilic than that of original film. The experiment of PHBHHx flushed by phosphate buffer solution (PBS) proves that the coated SF shows stronger immobilization on the plasma-treated film than that on the untreated film. The cell viability assay demonstrates that SF-coated PHBHHx films treated by the plasma significantly supports the proliferation and growth of the human smooth muscle cells (HSMCs). Furthermore, the scanning electron microscopy and hemotoylin and eosin (HE) staining show that HSMCs formed a cell sub-monolayer and secreted a large amount of extracellular matrix (ECM) on the films after one week's culture. The silk fibroins modify the plasma-treated PHBHHx film, providing a material potentially applicable in the cardiovascular tissue engi-neering.展开更多
An economical and environmental sustainability of bioplastic production is dependent on the use of low cost and waste C-sources as raw materials. OMW (Olive Mill Wastewater) with its high organic load represents a d...An economical and environmental sustainability of bioplastic production is dependent on the use of low cost and waste C-sources as raw materials. OMW (Olive Mill Wastewater) with its high organic load represents a dangerous polluting waste. Herein the authors present an integrated process for the simultaneous recovery of polyphenols, high value natural antioxidants, production of PHAs (polyhydroxyalkanotes), thermoplastic bio-polymers, in particular of PHB (poly-3-hydroxybutyrate) starting from OMW. The combination of membrane filtration and bacterial digestion of OMW resulted in very high yields of polyphenols (3 2.5 g/L) and PHB (31.4 mg/L.h) if compared with the state of the art. These results make the technical approach described here effective for reducing the polluting effect of OMW and maximizing the valuable product yield. Moreover the process is readily suitable for an industrial scale PHB production from OMW.展开更多
Poly (3-hydroxybutyrate-co-3-hydroxyvalerate)/Organophilic montmorillonite (PHBV/OMMT) nanocomposites were prepared and the biodegradability of the PHBV/OMMT nanocomposites was studied by a cultivation degrading metho...Poly (3-hydroxybutyrate-co-3-hydroxyvalerate)/Organophilic montmorillonite (PHBV/OMMT) nanocomposites were prepared and the biodegradability of the PHBV/OMMT nanocomposites was studied by a cultivation degrading method in soil suspension. The relationship between structure and biodegradability of PHBV/OMMT nanocomposites was investigated. The results showed that the biodegradability of PHBV/OMMT nanocomposites decreased with increasing amount of OMMT and it was related to the number of PHBV degrading microorganisms in degradation environment, the anti-microbial property of OMMT and the degree of crystallinity of the nanocomposites.展开更多
Blends of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(butylene succinate-adipate) (PBSA), both biodegradable semicrystalline polyesters, were prepared with the ratio of PHBHHx/PBSA ranging from 80/...Blends of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(butylene succinate-adipate) (PBSA), both biodegradable semicrystalline polyesters, were prepared with the ratio of PHBHHx/PBSA ranging from 80/20 to 20/80 by melt mixing method. Differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), dynamic mechanical thermal analysis (DMA), polarizing optical microscopy (POM) and wide angle X-ray diffractometer (WAXD) were used to study the miscibility and crystallization behavior of PHBHHx/PBSA blends. Experimental results indicate that PHBHHx is immiscible with PBSA as shown by the almost unchanged glass transition temperature and the biphasic melt.展开更多
Porous poly(3 hydroxybutyrate)(PHB) membranes were prepared by microemulsion templates. The influence of microemulsion templates on pore size and porosity of the PHB membranes were studied. Preliminary studies showed...Porous poly(3 hydroxybutyrate)(PHB) membranes were prepared by microemulsion templates. The influence of microemulsion templates on pore size and porosity of the PHB membranes were studied. Preliminary studies showed that the pore size made by microemulsion templates were smaller and were estimated in the range of 100~500 nanometer. In this research, the ultraviolet/visible light spectrometer was applied in the investigation of H 2O/Span85 Tween60/chloroform reserve microemulsion. Surfactant content(P) and water content(R) were optimized. Furthermore, the effects of variation of P and R on the pore size and porosity of PHB films were discussed.展开更多
A novel kind of copolymer with ABA-type block structure was synthesized by anionic ring-opening polymerization of beta-butyrolactone (beta-BL) in the presence of a PEG-based dicarboxylates as macroinitiators which wer...A novel kind of copolymer with ABA-type block structure was synthesized by anionic ring-opening polymerization of beta-butyrolactone (beta-BL) in the presence of a PEG-based dicarboxylates as macroinitiators which were prepared by the esterification of aliphatic cyclic anhydride and poly(ethylene glycol) (PEG) oligomers (M-n = 2000, 4000 and 6000) and conversion of potassium dicarboxylates. The resultant copolymers as well as the intermediates were characterized by IR, H-1-NMR and GPC.展开更多
Accumulation of recalcitrant plastics in the environment has become a world-wide problem in today’s societies. Rapid depletion of natural resources for synthetic plastics along with environmental concerns has directe...Accumulation of recalcitrant plastics in the environment has become a world-wide problem in today’s societies. Rapid depletion of natural resources for synthetic plastics along with environmental concerns has directed research towards finding alternatives to petroleum-based polymers. Poly(3-hydroxybutyric acid) P(3HB), as one of these alternatives, have attracted much attention in recent years due to their varied mechanical properties, biocompatibility and biodegradability. The aim of this study was to identify an agro-industrial waste resource economically suitable for large-scale production of P(3HB), to optimize the production using Response Surface Methodology in small-scale and subsequently, to test the production in a continuously stirred tank reactor. Among a range of agro-industrial waste, orange peel was selected as the most suitable for P(3HB) production. P(3HB) concentration of 1.24 g P(3HB)/L culture broth with 41% P(3HB)/dcw yield was obtained using orange peel as the sole carbon source in optimized medium with a modified strain of Bacillus subtilis (B. subtilis OK2).展开更多
Recently,poly(ethylene oxide)(PEO)-based solid polymer electrolytes have been attracting great attention,and efforts are currently underway to develop PEO-based composite electrolytes for next generation high performa...Recently,poly(ethylene oxide)(PEO)-based solid polymer electrolytes have been attracting great attention,and efforts are currently underway to develop PEO-based composite electrolytes for next generation high performance all-solid-state lithium metal batteries.In this article,a novel sandwich structured solid-state PEO composite electrolyte is developed for high performance all-solid-state lithium metal batteries.The PEO-based composite electrolyte is fabricated by hot-pressing PEO,LiTFSI and Ti_(3)C_(2)T_(x) MXene nanosheets into glass fiber cloth(GFC).The as-prepared GFC@PEO-MXene electrolyte shows high mechanical properties,good electrochemical stability,and high lithium-ion migration number,which indicates an obvious synergistic effect from the microscale GFC and the nanoscale MXene.Such as,the GFC@PEO-1 wt%MXene electrolyte shows a high tensile strength of 43.43 MPa and an impressive Young's modulus of 496 MPa,which are increased by 1205%and 6048%over those of PEO.Meanwhile,the ionic conductivity of GFC@PEO-1 wt%MXene at 60℃ reaches 5.01×10^(-2) S m^(-1),which is increased by around 200%compared with that of GFC@PEO electrolyte.In addition,the Li/Li symmetric battery based on GFC@PEO-1 wt%MXene electrolyte shows an excellent cycling stability over 800 h(0.3 mA cm^(-2),0.3 mAh cm^(-2)),which is obviously longer than that based on PEO and GFC@PEO electrolytes due to the better compatibility of GFC@PEO-1 wt%MXene electrolyte with Li anode.Furthermore,the solid-state Li/LiFePO_(4) battery with GFC@PEO-1 wt%MXene as electrolyte demonstrates a high capacity of 110.2–166.1 mAh g^(-1) in a wide temperature range of 25–60C,and an excellent capacity retention rate.The developed sandwich structured GFC@PEO-1 wt%MXene electrolyte with the excellent overall performance is promising for next generation high performance all-solid-state lithium metal batteries.展开更多
This study was aimed to construct a biodegradable but reliable 3-β-hydroxybutymte biosensor. In this context a versatile paper based biosensor, quickly, easily and cheaply fabricated is reported. The procedure of fab...This study was aimed to construct a biodegradable but reliable 3-β-hydroxybutymte biosensor. In this context a versatile paper based biosensor, quickly, easily and cheaply fabricated is reported. The procedure of fabrication is based on the assumption that the introduction of the enzyme in the carbon ink will allow enzyme stabilization and facilitate the study of the catalysis of enzymes and the detection of substrates. To prove this concept we use the enzyme 3-hydroxybutyrate dehydrogenase, in aqueous solution. This enzyme was chosen because it catalyzes the 3-β-hydroxybutyrate, which results from ketoacidosis. The quantification this substance in the diabetics' blood is very important as it can increase the reliability of the diagnosis of glycaemia. To prove the multi-use of this biosensor we not only study the redox process in steady state and during the catalytic process, but also detected and quantify the 3-β-hydroxybutyrate. Our results showed that it was possible to study the redox process that occurred during the catalysis and to confirm the amino acid residues that participate in it. It was also observed that glucose and ascorbic acid can interfere in the detection and quantification of the 3-β-hydroxybutyrate, what should be in mind when the quantification of the 3-β-hydroxybutyrate is made in blood samples.展开更多
With concerns in energy crisis and global warming, researchers are actively investigating alternative energy renewable solutions. Among the various methods, piezoelectric transduction stands out due to its impressive ...With concerns in energy crisis and global warming, researchers are actively investigating alternative energy renewable solutions. Among the various methods, piezoelectric transduction stands out due to its impressive electromechanical coupling factor and coefficient. As a result, piezoelectric energy harvesting has garnered significant attention from the scientific community. In this study, we explored methods to enhance the piezoelectric properties of polyvinylidene fluoride (PVDF) through two distinct approaches. The first approach involved applying external high voltages at various stages during the mixture reaction. The goal was to determine whether this voltage application could alter or enhance PVDF’s piezoelectric conformation by improving the alignment of polarized dipoles. In the second part of our study, we investigated the effects of incorporating various nanostructures (including Iron Oxide, Magnesium Oxide, and Zinc Oxide) into PVDF. To analyze changes in PVDF’s crystalline structure, we utilized Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD) techniques. Additionally, we measured the electric polarization of samples using a Precision LC Meter and examined the morphology of nanofibers through Scanning Electron Microscopy (SEM).展开更多
文摘Poly[R-3-hydroxybutyrate-co-(R-3-hydroxyvalerate)] (PHBVs) copolymers are promising biopolymers, which could substitute petroleum-based plastics for various applications. PHB and PHBV pellets were processed on a customized 3D printer via Fused Granular Manufacturing (FGM) approach modified with a Mahor screw extruder. To anticipate the behaviour of PHBVs when transformed using conventional thermo-mechanical shaping processes, thermal and mechanical analyses were carried out in order to better understand the effect of annealing temperature on their crystallization behaviour and mechanical properties of PHB polymer and PHBV copolymer. The objectives of the present work were to propose an experimental strategy to study the melting and crystallization events, crystalline structure changes, and mechanical performances of both PHB homopolymer and PHBV copolymer according to identical thermal annealing treatments. A monitoring of 3D printed PHB and PHBV structures was achieved by coupling Differential Scanning Calorimetry (DSC) and tensile tests. .
基金ACKNOWLEDGMENT This work was supported by the Key Science Foundation of Education Ministry of China and the Anhui Science Foundation.
文摘The miscibility and crystallization of solution casting biodegradable poly(3-hydroxybuty- rate)/poly(ethylene succinate) (PHB/PES) blends was investigated by differential scanning calorimetry, rheology, and optical microscopy. The blends showed two glass transition temperatures and a depression of melting temperature of PHB with compositions in phase diagram, which indicated that the blend was partially miscible. The morphology observation supported this result. It was found that the PHB and PES can crystallize simultaneously or upon stepwise depending on the crystallization temperatures and compositions. The spherulite growth rate of PHB increased with increasing of PES content. The influence of compositions on the spherulitic growth rate for the partially miscible polymer blends was discussed.
基金New Century Excellent Talents in University of China(NCET-05-0358)the National Natural Science Foundation of China(20625308)
文摘Poly-3-hydroxybutyrate (PHB) can be produced by various species of bacteria. Among the possible carbon sources, both methane and methanol could be a suitable substrate for the production of PHB. Methane is cheap and plentiful not only as natural gas, but also as biogas. Methanol can also maintain methanotrophic activity in some conditions. The methanotrophic strain Methylosinus trichosporium IMV3011 can accumulate PHB with methane and methanol in a brief nonsterile process. Liquid methanol (0.1%) was added to improve the oxidization of methane. The studies were carried out using shake flasks. Cultivation was performed in two stages: a continuous growth phase and a PHB accumulation phase under the conditions short of essential nutrients (ammonium, nitrate, phosphorus, copper, iron (Ⅲ), magnesium or ethylenediamine tetraacetate (EDTA)) in batch culture. It was found that the most suitable growth time for the cell is 144 h. Then an optimized culture condition for second stage was determined, in which the PHB concentration could be much increased to 0.6 g/L. In order to increase PHB content, citric acid was added as an inhibitor of tricarboxylic acid cycle (TCA). It was found that citric acid is favorable for the PHB accumulation, and the PHB yield was increased to 40% (w/w) from the initial yield of 12% (w/w) after nutrient deficiency cultivation. The PHB produced is of very high quality with molecular weight up to 1.5 × 10^6Da.
基金Supported by EPSRC Doctoral Training Centre in Regenerative Medicine and the HYANJI Scaffold Project (European Commission Framework 7 program)
文摘AIM: To establish the potential of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) as a material for tendon repair. METHODS: The biocompatibility of PHBHHx with both rat tenocytes (rT) and human mesenchymal stem cells (hMSC) was explored by monitoring adhesive characteristics on films of varying weight/volume ratios coupled to a culture atmosphere of either 21% O2 (air) or 2% O2 (physiological normoxia). The diameter and stiffness of PHBHHx films was established using optical coherence tomography and mechanical testing, respectively. RESULTS: Film thickness correlated directly with weight/volume PHBHHx (r2 = 0.9473) ranging from 0.1 mm (0.8% weight/volume) to 0.19 mm (2.4% weight/volume). Film stiffness on the other hand displayed a biphasic response which increased rapidly at values > 1.6% weight/volume. Optimal cell attachment of rT required films of ≥ 1.6% and ≥ 2.0% weight/volume PHBHHx in 2% O2 and 21% O2 respectively. A qualitative adhesion increase was noted for hMSC in films ≥ 1.2% weight/volume, becoming significant at 2% weight/volume in 2% O2. An increase in cell adhesion was also noted with ≥ 2% weight/volume PHBHHx in 21% O2. Cell migration into films was not observed. CONCLUSION: This evaluation demonstrates that PHBHHx is a suitable polymer for future cell/polymer replacement strategies in tendon repair.
文摘Poly(3-hydroxybutyrate) (PHB) is an intracellular carbon and energy storage material accumulated by many kinds of microorganism under unfavorable growth conditions. For the production of PHB, Alcaligenes eutrophus has been widely used because it is easy to grow, and its physiological and biochemical changes during the PHB synthesis is understood in details. A very high concentration and productivity of PHB could be obtained by fed-batch culture of Alcaligenes eutrophus with phosphate limitation in 50 L fermenter.
基金This work was financially supported by the Hong Kong Polytechnic University (Grant YD37)the Research Grant Council of the Hong Kong Special Administration Region, China (Nos. Polyu5272/01M, Polyu5257/02M, Polyu5403/03M)
文摘Biosynthesis and thermal properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with different HV (hydrovalerate) content produced by a Bacillus cereus strain were investigated. A large variety of HV contents (up to about 90 mol%) of PHBV could be produced by this strain. Combined nitrogen sources containing both yeast extract and ammonium sulphate were better for cell growth and polyhydroxyalkanoates (PHA) production than either yeast extract or ammonium sulphate alone. Propionic acid is more favorable for the production of HV content than that of valeric acid. Finally, thermal properties of PHBV produced by this strain are found close to the results of other groups.
文摘Tissue engineered scaffold is one of the hopeful therapies for the patients with organ or tissue damages. The key element for a tissue engineered scaffold material is high biocompatibility. Herein the poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) film was irradiated by the low temperature atmospheric plasma and then coated by the silk fibroins (SF). After plasma treatment, the surface of PHBHHx film became rougher and more hydrophilic than that of original film. The experiment of PHBHHx flushed by phosphate buffer solution (PBS) proves that the coated SF shows stronger immobilization on the plasma-treated film than that on the untreated film. The cell viability assay demonstrates that SF-coated PHBHHx films treated by the plasma significantly supports the proliferation and growth of the human smooth muscle cells (HSMCs). Furthermore, the scanning electron microscopy and hemotoylin and eosin (HE) staining show that HSMCs formed a cell sub-monolayer and secreted a large amount of extracellular matrix (ECM) on the films after one week's culture. The silk fibroins modify the plasma-treated PHBHHx film, providing a material potentially applicable in the cardiovascular tissue engi-neering.
文摘An economical and environmental sustainability of bioplastic production is dependent on the use of low cost and waste C-sources as raw materials. OMW (Olive Mill Wastewater) with its high organic load represents a dangerous polluting waste. Herein the authors present an integrated process for the simultaneous recovery of polyphenols, high value natural antioxidants, production of PHAs (polyhydroxyalkanotes), thermoplastic bio-polymers, in particular of PHB (poly-3-hydroxybutyrate) starting from OMW. The combination of membrane filtration and bacterial digestion of OMW resulted in very high yields of polyphenols (3 2.5 g/L) and PHB (31.4 mg/L.h) if compared with the state of the art. These results make the technical approach described here effective for reducing the polluting effect of OMW and maximizing the valuable product yield. Moreover the process is readily suitable for an industrial scale PHB production from OMW.
基金The National Natural Science Foundation of China (No. 20374032) Chinese Education Ministry Foundation for N & T Joint Academy
文摘Poly (3-hydroxybutyrate-co-3-hydroxyvalerate)/Organophilic montmorillonite (PHBV/OMMT) nanocomposites were prepared and the biodegradability of the PHBV/OMMT nanocomposites was studied by a cultivation degrading method in soil suspension. The relationship between structure and biodegradability of PHBV/OMMT nanocomposites was investigated. The results showed that the biodegradability of PHBV/OMMT nanocomposites decreased with increasing amount of OMMT and it was related to the number of PHBV degrading microorganisms in degradation environment, the anti-microbial property of OMMT and the degree of crystallinity of the nanocomposites.
基金The National Natural Science Foundation of China (No. 20374032) and Tianjin Science and Technology Key Project (No. 05YFSZSF02200)
文摘Blends of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(butylene succinate-adipate) (PBSA), both biodegradable semicrystalline polyesters, were prepared with the ratio of PHBHHx/PBSA ranging from 80/20 to 20/80 by melt mixing method. Differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), dynamic mechanical thermal analysis (DMA), polarizing optical microscopy (POM) and wide angle X-ray diffractometer (WAXD) were used to study the miscibility and crystallization behavior of PHBHHx/PBSA blends. Experimental results indicate that PHBHHx is immiscible with PBSA as shown by the almost unchanged glass transition temperature and the biphasic melt.
文摘Porous poly(3 hydroxybutyrate)(PHB) membranes were prepared by microemulsion templates. The influence of microemulsion templates on pore size and porosity of the PHB membranes were studied. Preliminary studies showed that the pore size made by microemulsion templates were smaller and were estimated in the range of 100~500 nanometer. In this research, the ultraviolet/visible light spectrometer was applied in the investigation of H 2O/Span85 Tween60/chloroform reserve microemulsion. Surfactant content(P) and water content(R) were optimized. Furthermore, the effects of variation of P and R on the pore size and porosity of PHB films were discussed.
文摘A novel kind of copolymer with ABA-type block structure was synthesized by anionic ring-opening polymerization of beta-butyrolactone (beta-BL) in the presence of a PEG-based dicarboxylates as macroinitiators which were prepared by the esterification of aliphatic cyclic anhydride and poly(ethylene glycol) (PEG) oligomers (M-n = 2000, 4000 and 6000) and conversion of potassium dicarboxylates. The resultant copolymers as well as the intermediates were characterized by IR, H-1-NMR and GPC.
文摘Accumulation of recalcitrant plastics in the environment has become a world-wide problem in today’s societies. Rapid depletion of natural resources for synthetic plastics along with environmental concerns has directed research towards finding alternatives to petroleum-based polymers. Poly(3-hydroxybutyric acid) P(3HB), as one of these alternatives, have attracted much attention in recent years due to their varied mechanical properties, biocompatibility and biodegradability. The aim of this study was to identify an agro-industrial waste resource economically suitable for large-scale production of P(3HB), to optimize the production using Response Surface Methodology in small-scale and subsequently, to test the production in a continuously stirred tank reactor. Among a range of agro-industrial waste, orange peel was selected as the most suitable for P(3HB) production. P(3HB) concentration of 1.24 g P(3HB)/L culture broth with 41% P(3HB)/dcw yield was obtained using orange peel as the sole carbon source in optimized medium with a modified strain of Bacillus subtilis (B. subtilis OK2).
基金support of the Fundamental Research Funds for the Central Universities(No.2022CDJQY-004)the Fund for Innovative Research Groups of Natural Science Foundation of Hebei Province(No.A2020202002).
文摘Recently,poly(ethylene oxide)(PEO)-based solid polymer electrolytes have been attracting great attention,and efforts are currently underway to develop PEO-based composite electrolytes for next generation high performance all-solid-state lithium metal batteries.In this article,a novel sandwich structured solid-state PEO composite electrolyte is developed for high performance all-solid-state lithium metal batteries.The PEO-based composite electrolyte is fabricated by hot-pressing PEO,LiTFSI and Ti_(3)C_(2)T_(x) MXene nanosheets into glass fiber cloth(GFC).The as-prepared GFC@PEO-MXene electrolyte shows high mechanical properties,good electrochemical stability,and high lithium-ion migration number,which indicates an obvious synergistic effect from the microscale GFC and the nanoscale MXene.Such as,the GFC@PEO-1 wt%MXene electrolyte shows a high tensile strength of 43.43 MPa and an impressive Young's modulus of 496 MPa,which are increased by 1205%and 6048%over those of PEO.Meanwhile,the ionic conductivity of GFC@PEO-1 wt%MXene at 60℃ reaches 5.01×10^(-2) S m^(-1),which is increased by around 200%compared with that of GFC@PEO electrolyte.In addition,the Li/Li symmetric battery based on GFC@PEO-1 wt%MXene electrolyte shows an excellent cycling stability over 800 h(0.3 mA cm^(-2),0.3 mAh cm^(-2)),which is obviously longer than that based on PEO and GFC@PEO electrolytes due to the better compatibility of GFC@PEO-1 wt%MXene electrolyte with Li anode.Furthermore,the solid-state Li/LiFePO_(4) battery with GFC@PEO-1 wt%MXene as electrolyte demonstrates a high capacity of 110.2–166.1 mAh g^(-1) in a wide temperature range of 25–60C,and an excellent capacity retention rate.The developed sandwich structured GFC@PEO-1 wt%MXene electrolyte with the excellent overall performance is promising for next generation high performance all-solid-state lithium metal batteries.
文摘This study was aimed to construct a biodegradable but reliable 3-β-hydroxybutymte biosensor. In this context a versatile paper based biosensor, quickly, easily and cheaply fabricated is reported. The procedure of fabrication is based on the assumption that the introduction of the enzyme in the carbon ink will allow enzyme stabilization and facilitate the study of the catalysis of enzymes and the detection of substrates. To prove this concept we use the enzyme 3-hydroxybutyrate dehydrogenase, in aqueous solution. This enzyme was chosen because it catalyzes the 3-β-hydroxybutyrate, which results from ketoacidosis. The quantification this substance in the diabetics' blood is very important as it can increase the reliability of the diagnosis of glycaemia. To prove the multi-use of this biosensor we not only study the redox process in steady state and during the catalytic process, but also detected and quantify the 3-β-hydroxybutyrate. Our results showed that it was possible to study the redox process that occurred during the catalysis and to confirm the amino acid residues that participate in it. It was also observed that glucose and ascorbic acid can interfere in the detection and quantification of the 3-β-hydroxybutyrate, what should be in mind when the quantification of the 3-β-hydroxybutyrate is made in blood samples.
文摘With concerns in energy crisis and global warming, researchers are actively investigating alternative energy renewable solutions. Among the various methods, piezoelectric transduction stands out due to its impressive electromechanical coupling factor and coefficient. As a result, piezoelectric energy harvesting has garnered significant attention from the scientific community. In this study, we explored methods to enhance the piezoelectric properties of polyvinylidene fluoride (PVDF) through two distinct approaches. The first approach involved applying external high voltages at various stages during the mixture reaction. The goal was to determine whether this voltage application could alter or enhance PVDF’s piezoelectric conformation by improving the alignment of polarized dipoles. In the second part of our study, we investigated the effects of incorporating various nanostructures (including Iron Oxide, Magnesium Oxide, and Zinc Oxide) into PVDF. To analyze changes in PVDF’s crystalline structure, we utilized Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD) techniques. Additionally, we measured the electric polarization of samples using a Precision LC Meter and examined the morphology of nanofibers through Scanning Electron Microscopy (SEM).