Different Concentrations Of Glycerol Research Articles

Structure and Electrical Properties of Polymer Electrolyte Based on Plasticized Chitosan Grafted Polymethyl Methacrylate (Ch-g-PMMA)- Magnesium Triflate for Electrochemical Double Layer Capacitor

Polymer electrolytes have received much attention as materials used in batteries, supercapacitors, sensors and solar cells. Most of the polymer electrolytes reported are based on synthetic polymer, therefore it is difficult to recycle as it has poor degradability and ends up being a waste. In recent years, biopolymers gained much interest in replacing environmentally unfriendly polymers. Various studies have been done to accomplish polymer electrolytes with high conductivity and long-term safety. This study’s objective is to prepare plasticized Ch-g-PMMA-based polymer electrolyte by introducing the magnesium triflate salt and glycerol plasticizer. The grafted polymer of Ch-g-PMMA was prepared using gamma (γ) radiation. The grafted polymer of Ch-g-PMMA with 0.4 g of Mg(Tf)2 and different concentrations of glycerol has been prepared by using the solution casting technique. To achieve this study, the prepared plasticized Ch-g-PMMA-Mg(Tf)2 polymer electrolytes are characterized by XRD, FTIR, EIS and LSV techniques. XRD was carried out to determine the change in crystallinity and the amorphous structure of the plasticized Ch-g-PMMA-Mg(Tf)2 polymer. FTIR reveals the occurrence of complexation between Ch-g-PMMA polymer, Mg(Tf)2 salt and glycerol plasticizer. The grafted Ch-g-PMMA-Mg(Tf)2 was added with different concentrations of glycerol from 0 to 50 wt%. The Ch-g-PMMA-Mg(Tf)2 polymer electrolyte with 50 wt% of glycerol shows the highest ionic conductivity of 1.50×10−4 S·cm−1 compared with other samples. The increase in mobility of ions and the number of charge carriers has enhanced ionic conductivity. Based on the LSV analysis, the highest conducting Ch-g-PMMA-Mg(Tf)2 polymer with 50 wt% of glycerol was found electrochemically stable up to 3.2 V. The goal of this study is to determine the structure and electrical properties as well as the window stability of plasticized Ch-g-PMMA-Mg(Tf)2. The best outcome was produced by adding the 50 wt% of glycerol into the Ch-g-PMMA-Mg(Tf)2 which increased further by 1 order of magnitude. HIGHLIGHTS The ionic conductivity of the Ch-g-PMMA increases by introducing magnesium triflate salt and glycerol plasticizer which enhance the amorphous state and decrease the crystallinity The prepared plasticized Ch-g-PMMA-Mg(Tf)2 polymer electrolytes are characterized by XRD, FTIR, EIS and LSV techniques The highest ionic conductivity are obtained by added 50 wt% glycerol to the grafted polymer CH-g-PMMA-Mg(Tf)2 which is 1.50×10−4 S·cm−1 GRAPHICAL ABSTRACT

Coupling of NAD(P)H:FMN-oxidoreductase and luciferase from luminous bacteria in a viscous medium: Finding the weakest link in the chain.

The study aims at revealing the mechanisms of the viscous medium effects on the kinetic features of NAD(P)H:FMN-oxidoreductase from luminous bacteria (Red), which are exhibited in a single enzyme assay and in coupling with bacterial luciferase (BLuc). Different concentrations of glycerol and sucrose were used to vary the medium viscosity. The activity of Red, alone and in the presence of BLuc, was analyzed, as well as BLuc activity in the presence of Red, whereas in the absence of BLuc, the Red activity was suppressed in viscous medium, and in the presence of BLuc, the increase in Red activity was observed at low glycerol concentrations (5-20 wt%). The interaction of glycerol and sucrose with Red substrates FMN and NADH was studied using absorption spectroscopy and molecular dynamics. Glycerol was found to form hydrogen bonds with the phosphate groups of the substrates, unlike sucrose. A mechanism for the activation of Red in the presence of BLuc in glycerol solutions through the acceleration of FMN reoxidation was proposed. Thus, it was concluded that, under the conditions used, the weakest link of the coupled enzyme system BLuc-Red in viscous medium is the FMN concentration, which depends on Red activity and the medium viscosity.

The effect of glycerol additive on high value-added chemicals from tobacco waste pyrolysis

It is of significant importance to understand the role of glycerol additive for the improvement of the energy recovery during tobacco-waste pyrolysis. Utilizing ReaxFF-based molecular dynamic simulation, herein, we systematically studied the pyrolysis mechanism of tobacco with different concentrations of glycerol (5%, 10%, 16.5%, 20%, 25%) at different temperatures (1800 K, 2000 K, 2300 K, 2500 K, 2800 K). The calculation shows that a temperature of 2000 K is the optimal temperature for producing methanol and ethanol. Furthermore, the concentration of glycerol had a significant effect on promoting methanol production at high temperatures. Methanol's main generation pathway was influenced by temperature and glycerol concentration, while the primary pathway of ethanol production was independent of them. Moreover, a pyrolysis reaction framework was created for methanol and ethanol production, and their main formation reactions were validated. Finally, a chemical kinetic analysis of the pyrolysis process confirmed the accuracy of the ReaxFF MD simulations.

Investigation of the influence of plasticizers on the biodegradability of cellulose acetate

AbstractIn order to evaluate the biodegradability of the cellulose acetate (CA) films plasticized with different concentrations of glycerol (GLY) or triethyl citrate (TEC), analysis of scanning electron microscopy (SEM), Fourier transfer infrared spectroscopy (FTIR), and thermogravimetric analyses (TGA) were conducted through 180 days. Throughout the analysis, indicators of plasticizer exudation were observed, including changes in visual appearance and mass loss, ranging from 39.141% and 20.663% (first day) up to 0.524% and 0.488% (last day) for TEC and GLY plasticizer based films, respectively. Changes were also noted in the infrared spectrum, and TGA plots with polymer degradation peaks from 332.09 to 400.96 cm−1 for both plasticizers based films (TEC and GLY, respectively), regardless of the day of analysis. All assays revealed plasticizer losses, but there was no evidence of films' biodegradation during the experimental time. In perspective, this systematic approach can be extended to study other polymers and other biodegradation conditions.

Glycerol-mediated lysosomal associated proteins as a novel anticancer theory in colon cancer cell line

Background: Colon cancer begins in the large intestine (colon) and is aggressive due to late diagnosis, so there is a poor prognosis and higher mortality rates, as reported. Colon cancer has become a vital research area requiring more investigation of cellular signaling in its initiation and development. Aim: The study aimed to investigate the biological effects of Glycerol in cell proliferation and the possible regulation of cellular signaling by exogenous treatment of Glycerol in colon cancer cells compared with colon mucosal epithelial cells. 
 Materials and Methods: The influence of Glycerol on cell viability rate was monitored by inverted microscopy, and the number of living cells was assessed upon incubation with different concentrations of Glycerol. We further inspected the apoptotic rate of CaCo-2 cells by using Annexin-V staining by flow cytometry. Moreover, we achieved the expression profile of lysosomal-associated proteins, LAMP-1 and LAMP-2, in treated cells using qRT-PCR and flow cytometry. Finally, we monitored the released pro-inflammatory cytokines and anti-inflammatory in response to Glycerol treatment using ELISA assay. 
 Results: Our results showed that Glycerol treatment could prevent cancer cell proliferation without any detectable cytotoxic occurrence in the normal cells. Interestingly, we evidenced that Glycerol targets and breaks down the lysosomal activities by inhibiting the expression profile of both LAMP-1 and LAMP-2. Furthermore, Glycerol treatment successfully adjusted the production of IL-6 and IL-8 as pro-inflammatory cytokines while stimulating the production of anti-inflammatory cytokines, IL-4 and IL-10, in a time-dependent manner. 
 Conclusion: These data provide evidence for the anti-cancer properties of Glycerol in colon cancer cells via targeting lysosomal activities and disturbance of the degradation events in colon cancer cells. 

Contribution of the Tyrosinase (MoTyr) to Melanin Synthesis, Conidiogenesis, Appressorium Development, and Pathogenicity in Magnaporthe oryzae.

Dihydroxynapthalene-(DHN) and L-dihydroxyphenylalanine (L-DOPA) are two types of dominant melanin in fungi. Fungal melanins with versatile functions are frequently associated with pathogenicity and stress tolerance. In rice blast fungus, Magnaporthe oryzae, DHN melanin is essential to maintain the integrity of the infectious structure, appressoria; but the role of the tyrosinase-derived L-DOPA melanin is still unknown. Here, we have genetically and biologically characterized a tyrosinase gene (MoTyr) in M. oryzae. MoTyr encodes a protein of 719 amino acids that contains the typical CuA and CuB domains of tyrosinase. The deletion mutant of MoTyr (ΔMoTyr) was obtained by using a homologous recombination approach. Phenotypic analysis showed that conidiophore stalks and conidia formation was significantly reduced in ΔMoTyr. Under different concentrations of glycerol and PEG, more appressoria collapsed in the mutant strains than in the wild type, suggesting MoTyr is associated with the integrity of the appressorium wall. Melanin measurement confirmed that MoTyr loss resulted in a significant decrease in melanin synthesis. Accordingly, the loss of MoTyr stunted the conidia germination under stress conditions. Importantly, the MoTyr deletion affected both infection and pathogenesis stages. These results suggest that MoTyr, like DHN pigment synthase, plays a key role in conidiophore stalks formation, appressorium integrity, and pathogenesis of M. oryzae, revealing a potential drug target for blast disease control.

Physicochemical and structural properties of a bio-based antioxidant packaging film derived from Eremurus luteus root gum

A novel bio-based film from Eremurus luteus root gum (ELRG), as a new source of glucomannans, was fabricated and the effects of two plasticizers (glycerol and sorbitol) and their concentration (30, 40, and 50% w/w) on some physical, optical, barrier, antioxidant and mechanical properties, and microstructure of the films were investigated. The results demonstrated that the increase in the plasticizers’ concentration from 30% to 50% (w/w) increased the moisture content, solubility, and water vapor permeability (WVP) but decreased the contact angle of the ELRG films. The maximum antioxidant activity of the films was obtained by the addition of 50% of glycerol or sorbitol. The plasticized films by different concentrations of glycerol exhibited more extensibility and lower tensile strength in comparison with sorbitol films. The color analysis revealed that increasing both plasticizers’ concentrations caused the L value to increase while the ΔE value decreased. The more transparency and light transmission were observed for the sorbitol films. The SEM images indicated smooth and uniform surface morphology without cracks of plasticized films compared with the unplasticized film. The results of the present study suggest that ELRG is a good source to fabricate bio-based films for the food products packaging or carrying bioactive components. • ELRG introduced as a new biomaterial source for an antioxidant film fabrication. • Influence of plasticizer type and concentration was investigated. • Physical, barrier, and mechanical properties, and microstructure were determined. • Glycerol indicated greater efficiency than sorbitol in plasticizing ELRG films. • The glycerol plasticized films showed more antioxidant activity.

Effectiveness of Various Glycerol Concentrations as a Cryoprotectant in Frozen Semen of Pasundan Cattle

This study was conducted to determine the effectiveness of Glycerol as a cryoprotectant with various concentrations on the quality of Pasundan cattle semen. Semen was collected from seven bulls of Pasundan Cow using an artificial vagina twice a week for three months. The semen sample was added with a TRIS-Egg Yolk Extender containing 20% (v/v) egg yolk and treated with the addition of Glycerol with five different concentrations (G5=5%, G6=6%, G7=7%, G8= 8%, and G9=9%) were then performed with cryopreservation. A Completely Randomized Design (CRD) was used to examine the effect of five different concentrations of Glycerol on motility, intact plasma membrane (IPM), the integrity of acrosome cap (IAC), abnormalities, and recovery rate (RR) of spermatozoa after cryopreservation (post-thawing). The results of diluted Pasundan cattle semen evaluation showed that the addition of 7% Glycerol (G7) resulted in the best motility and IAC values (83.68% and 72.84%), the addition of 7% and 8% Glycerol (G7 and G8) resulted in the best IPM values (85.00% and 84.50%). The addition of 6%, 7%, 8%, and 9% Glycerol (G6, G7, G8, and G9) resulted in the lowest abnormality values (1%). On the post-thawing Pasundan cattle semen evaluation, the addition of 7% Glycerol (G7) resulted in the best motility, IAC, IPM, and RR values (54.49%, 38.57%, 54.29%, and 72.28%). Meanwhile, adding various Glycerol concentrations did not significantly affect the abnormality value of post-thawing spermatozoa. Generally, the addition of 7% Glycerol in semen extenders shows optimal results as a cryoprotectant.

Effect of glycerol concentrations on the mechanical and physical properties of chicken skin gelatin-tapioca starch composite films

This study aimed to elucidate the characteristics of chicken skin gelatin-tapioca starch composite films plasticized with different concentrations of glycerol. Gelatin-tapioca starch film solutions with different glycerol concentrations, namely A (0%), B (10%), C (20%), D (30%) and E (40%), were stirred at 45°C for 30 mins and oven-dried at 45°C. The results obtained showed that the tensile strength and Young’s modulus of the films had a negative linear correlation with glycerol concentrations, and positively correlated to the elongation at break (p<0.05). Water vapour permeability and water solubility of the films were increased with glycerol concentration increased. The plasticized films showed lower thermal stability as compared to unplasticized films. In conclusion, Film D (30% glycerol concentration) offers the most promising potential for industrial food packaging applications.

Biodegradable Films from Spray Dried Starch Inclusion Complexes with Bioactive Compounds—The Effect of Glycerol and pH

AbstractIn the present study, thermoplastic films are prepared using spray dried starch‐bioactive compound systems powders with different concentrations of glycerol (20% or 40%). The starch‐based films are produced by casting after dissolution under neutral (pH 7) or alkaline conditions (pH 12). Results reveal that elevated glycerol contents lead to increased moisture and hygroscopicity which is related to the availability of more ─OH groups. ANOVA shows that the glycerol concentration, the pH value, and the interactions of bioactive compounds with glycerol, bioactive compounds with pH, and glycerol with pH, influence significantly the mechanical properties of the thermoplastic starch films. Young's modulus of elasticity increases alongside with glycerol content, indicating improved flexibility of the films. Stress decreases with higher glycerol contents and lower pH while strain on the contrary, increases as the glycerol and pH increase in the films. Significant differences are also observed in water adsorption and water vapor transmission rate values. As expected, water adsorption increases with increasing relative humidity (RH) with the glycerol content positively affecting the water uptake by the films. Microscopic examination indicates the homogeneous distribution of the bioactive compounds in the matrix of the films.

Design, preparation, and characterization of silk fibroin/carboxymethyl cellulose wound dressing for skin tissue regeneration applications

AbstractSilk fibroin (SF) has been broadly applied in wound dressing fabrication because of its proper features for wound healing. In this work, we developed a carboxymethyl cellulose (CMC)/gelatin blend film with different concentrations of glycerol, and modified the optimized film with an SF layer through electrospinning process. Tensile strength and cell viability evaluation of blend films demonstrated that the glycerol content of 3% could be suitable as the substrate layer for the two‐layer wound dressing. The morphology of the blend film and electrospun nanofibers was obtained from scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). It concluded that structural changes had been occurred in both layers after cross‐linking with glutaraldehyde vapor. Further, it was shown that the mechanical properties of the two‐layer enhanced with the addition of SF. Moreover, the swelling ratio was higher than those of SF itself, due to the hydrophilic property of CMC/gelatin blend film. The biocompatibility of fibroblasts was investigated by MTT assay, and the coating showed an improvement in cell proliferation because of the cytocompatibility nature of SF. All results suggest that the prepared wound dressing could be a desirable candidate for wound healing applications.

Biosynthesis of silver nanoparticles with Chlorella sp.

This work shows the results of the biosynthesis of silver nanoparticles using the microalga Chlorella sp, using growth media with different concentrations of glycerol, between 5%–20%, and different light and temperature conditions. The synthesis of nanoparticles was studied using supernatants and pellets from autotrophic, heterotrophic and mixotrophic cultures of the microalga. The presence of nanoparticles was verified by ultraviolet-visible spectroscopy and the samples showing the highest concentration of nanoparticles were characterized by scanning electron microscopy. The mixotrophic growth conditions favored the excretion of exopolymers that enhanced the reduction of silver and thus the formation of nanoparticles. The nanoparticles obtained presented predominantly ellipsoidal shape with dimensions of 108 nm x 156 nm and 87 nm x 123 nm for the reductions carried out with the supernatants of the mixotrophic cultures with 5% and 10% glycerol, respectively.

Effects of Antifreeze Protein Type I and Glycerol in Diluents on Cryopreserved Goat Epididymal Sperm.

The effect of antifreeze protein (AFP) as a cryoprotectant used in different concentrations of glycerol on post-thaw quality of epididymal sperm was investigated. Sperm were isolated from 50 testicles, obtained from 25 healthy mature goat bucks, with progressive motility >80%, and total morphological abnormalities <10% were pooled in each replication. The semen samples were diluted with Tris-citrate-fructose-soybean lecithin extender containing different concentration of AFP [0 μg/mL (A0), 5 μg/mL (A5), 10 μg/mL (A10)]. Each concentration of AFP was added in an extender containing either 7% (G7) or 5% (G5) glycerol. Post-thaw total and progressive motility were found to be higher (p < 0.05) in groups A5G5 and A5G7. Plasma membrane integrity, sperm acrosome integrity, DNA integrity, acrosome intact sperm, and mitochondrial membrane potential were found to be higher (p < 0.05) in groups A5G5 and A10G5. Sperm viability was found to be higher (p < 0.05) in group A5G5, while lipid peroxidation was recorded lower (p < 0.05) in groups A5G5 and A5G7. Regarding the apoptosis occurrence, the results demonstrate higher (p < 0.05) live post-thawed spermatozoa for groups containing 5 μg/mL AFP with 5% and 7% glycerol in addition to the lowest (p < 0.05) value for groups containing 0 μg/mL AFP with 5% and 7% glycerol. Based on these results, the present study concludes that the addition of 5 μg/mL AFP in combination with 5% glycerol in freezing extender improves the post-thaw quality, structure, and function parameters for buck spermatozoa.

Improved stability and skin penetration through glycethosomes loaded with glycyrrhetinic acid.

In recent years, glycyrrhetinic acid (GA) has been popularly used in cosmetics because of its anti-inflammatory and anti-oxidant effects. However, due to the poor water solubility of GA and the barrier effect of human skin, the penetration of GA through the skin may be hindered. Liposomes are a common delivery system for functional compounds in cosmetics. Nonetheless, the stability and transdermal effect of traditional liposomes are limited. The aim of this work was to prepare a new liposome system that contained glycerol and ethanol to enhance the stability of the vesicles and promote the penetration of GA into the skin. The glycethosomes were prepared by ethanol injection and sonication method. The effects of different concentrations of glycerol and ethanol on the particle size, polydispersity (PDI), entrapment efficiency (EE), stability and rheological properties of vesicles were evaluated. Lipophilic and hydrophilic fluorescent probes were used to investigate the microviscosity of vesicles. In vitro permeation tests were performed with pig skin in Franz cells and the concentration of GA in different skin layers was determined by high-performance liquid chromatography (HPLC). The ability of different vesicles to induce lipid extraction and fluidization was analysed by using attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). When glycerol was 50% and ethanol was 25%, the obtained glycethosomes had the smallest particle size and the best stability with a mean particle size of 94.5nm, PDI 0.216 and 99.8% EE. Fluorescence probe studies indicated that the microviscosity of glycethosomes was the largest when the concentration of glycerol and ethanol was 50% and 25%, which was consistent with the storage stability of glycethosomes. It was found that the glycethosomes had the best transdermal effect and the total skin permeation percentage of GA was 20.67%, while those of ethosomes, glycerosomes, liposomes and dispersion were 10.56%, 9.38%, 7.78% and 5.02%, respectively. And glycethosomes had effectively lipid extraction and fluidization effect on the skin stratum corneum. Compared with other traditional liposomes, glycethosomes can significantly improve the stability of vesicles and the transdermal effect of GA. Glycethosomes is promising vesicles for the delivery of GA.

Exploiting Potential Biotechnological Applications of Poly-γ-glutamic Acid Low Molecular Weight Fractions Obtained by Membrane-Based Ultra-Filtration

Since the potentialities of applications of low molecular weight poly-γ-glutamic acid (γ-PGA) chains have been so far only partially explored, the separation of diverse molecular families of them, as well as their characterization for potential bioactivity and ability to form films, were investigated. Two different approaches based on organic solvent precipitation or on ultra- and nano-filtration membrane-based purification of inexpensive commercial material were employed to obtain size-specific γ-PGA fractions, further characterized by size exclusion chromatography equipped with a triple detector array and by ultra-high-performance liquid chromatography to assess their average molecular weight and their concentration. The γ-PGA low molecular weight fractions, purified by ultra-filtration, have been shown both to counteract the desiccation and the oxidative stress of keratinocyte monolayers. In addition, they were exploited to prepare novel hydrocolloid films by both solvent casting and thermal compression, in the presence of different concentrations of glycerol used as plasticizer. These biomaterials were characterized for their hydrophilicity, thermal and mechanical properties. The hot compression led to the attainment of less resistant but more extensible films. However, in all cases, an increase in elongation at break as a function of the glycerol content was observed. Besides, the thermal analyses of hot compressed materials demonstrated that thermal stability was increased with higher γ-PGA distribution po-lymer fractions. The obtained biomaterials might be potentially useful for applications in cosmetics and as vehicle of active molecules in the pharmaceutical field.

Effect of glycerol concentration, glycerol removal method, and straw type on the quality and fertility of frozen chicken semen

The long-term semen cryopreservation is increasingly crucial for conservation of endangered livestock and poultry species. Glycerol is the most widely used cryoprotectant for freezing chicken semen. Continuous improvement in details with glycerol may help increase the fertility of post-thawed semen. Two experiments were performed in the present study to investigate the effects of glycerol concentration, removal method, and straw type on the quality of post-thawed sperm. In experiment 1, glycerol concentration (3%, 5%, 7%, 9%, 11%, and 13%) and glycerol removal method (final dilution ratio 1:1, 1:2, 1:4, 1:8, 1:16, and 1:20) combination groups were investigated for post-thawed sperm quality, residual glycerol concentration, and fertility to find the best combinations. Experiment 2 was performed to evaluate the effects of straw type (0.25 and 0.5 mL) and glycerol concentration (3%, 5%, 7%, 9%, 11%, and 13%) on the post-thawed sperm quality. Results showed that post-thawed sperm motility of 6 glycerol concentration groups were different (P < 0.01). Sperm motility of 5%, 7%, 9%, 11% and 13% was higher than that of 3% (P < 0.01). There was no difference among different concentrations of glycerol in VSL, VCL, VAP, ALH, WOB, BCF, LIN, or STR (P > 0.05). As for the glycerol removal method, sperm motility of 1:8 dilution was the highest, followed by 1:1 and 1:2, while the difference among groups was not statistically significant (P = 0.11). Glycerol concentration and removal method had no interaction effect on sperm motion parameters (P > 0.05). The highest fertility (48.70%) was found for the 5% and 1:2 combination. There was no difference for sperm motility between 0.25 and 0.5 mL straws (P > 0.05). Glycerol concentration and straw type had no interaction effect on the sperm motion parameters (P > 0.05). It can be concluded from these observations that the combination of 5% glycerol and 1:2 dilution rendered higher fertility should be suggested in practice, and that both 0.25 and 0.50 mL straws fit the present procedure.

Biodegradable films of arrowroot starch (Maranta arundinacea) incorporated with floral extract of Tabebuia impetiginosa and copper sulfate: physical and physicochemical properties, and biodegradability and antibacterial activities

Biodegradable films of arrowroot starch were incorporated with floral extract of Tabebuia impetiginosa and copper sulfate and determined to the physical, physicochemical, biodegradability and antibacterial properties. The films were produced from arrowroot starch with different concentrations of glycerol, floral extract and copper sulfate solution. Thickness, humidity, solubility, biodegradability, water vapor colorimetry, color density, transparency, FT-IR and antibacterial activity tests were performed for Escherichia coli, Staphylococcus aureus, Salmonella serovar Thyphymurium and serovar Enteritidis. The films had a thickness between 0.23-0.33 mm, humidity between 8.53-12.22%, biodegradability between 88.98-100%, water vapor between 255.79-433.57 g m2 day, L* between 4.77-22.36; a* between -1.20 to 0.30; b* between -1.89 to 0.13; color density between -0.09 to 0.180; maximum transparency of 80%, inhibition activity between 9.13-26.26 mm for E. coli, 5.83-24.14 mm for S. aureus, 13-42-19.39 mm for S. serovar Thyphymurium, and 22.14-26.89 mm for S. serovar Enteritidis. The arrowroot biodegradable films incorporated with floral extract of Tabebuia impetiginosa and copper sulfate showed good physical, physicochemical, biodegradability and potential antibacterial activity.

Effect of Plasticizer and Concentration on Characteristics of Bioplastic Based on Cellulose Acetate from Kapok (Ceiba pentandra) Fiber

The synthetic plastics that made from petroleum material have been widely used in all industrial sectors. They cause some serious problems for the environment. There are semi-synthetic plastics or biodegradable plastics which are made from natural polymers such as cellulose to mitigate this problem. Biodegradable plastics can fulfill the needs of society because they can be decomposed easily into the environment. This research used laboratory experimental methods through several processes: kapok fiber isolation, cellulose acetate production and purification, and manufacture of bioplastics. The characteristics of bioplastics was analyzed using some parameters such as density, tensile strength, elongation, Young's modulus, water absorption, biodegradability, compound group analysis using Fouier-Transform Infrared Spectrometer (FTIR) and bioplastic morphology analysis by using Scanning electrone microscopy (SEM). This study aimed to determine the effect of the plasticizer type and concentration on the bioplastics characteristics that was divided into several different concentrations of glycerol and sorbitol plasticizers (20%, 30%, and 40%). The fabrication of composite bioplastics used the cellulose acetat from kapok fiber, starch, and types of plasticizer (glycerol, and sorbitol). The results of the study showed that the addition of different plasticizers, such as glycerol and sorbitol gave distinct effects on the bioplastics product characteristics. The optimum concentration of glycerol addition affected the bioplastic characteristics with the best results were 40% concentration generate density of 0.836 g/mL, tensile strength of 0.818 MPa, water absorption value of 22.23%, and degradation plastic mass about 39.7%. The addition of sorbitol also affected the bioplastic characteristics, where the best results were 40% concentration produced bioplastic density of 0.941 g/mL, percent elongation at 3.94%, young’s modulus of 0.726 MPa, and degradarion mass of 32.05%. The morphology of bioplastic showed the high homogeneity on concentrations of 40% glycerol and 30% sorbitol.

Three-dimensional diffusion coefficient measurement by a large depth-of-field rotating point spread function.

A prominent challenge in single-molecule localization microscopy is the real-time, fast, and accurate localization of nano-objects moving in three-dimensional (3D) samples. A well-established method for 3D single-molecule localization is the double-helix pointspread-function (DH-PSF) engineering, which uses additional optical elements to make the PSF exhibit different rotation angles with different nanoparticle depths. However, the compact main lobe size, effective detection depth, and precise conversion between rotation angle and depth are necessary, posing challenges to the DH-PSF generation method. Here we generate a more compact DH-PSF using Fresnel-zone-based spiral phases, and the pure phase mask achieves high transmission efficiency. The final generated DH-PSFs have a linear rotation rate at each axial position, showing a more accurate rotation angle and depth conversion. The Cramer-Rao lower limit calculation results show that the axial depth of DH-PSF extends to ∼11µm with an axial localization precision of ∼45nm at 3000 photons and average background noise of 15. We measured the diffusion coefficient of nanospheres in different concentrations of glycerol using the generated DH-PSF. The measured results are within 6% error from the theoretical values, indicating the superior performance of the DH-PSF for nanoparticle diffusion coefficient measurements.

Effect of emulsified oil droplets and glycerol content on the physicochemical properties of Persian gum-based edible films

This work focused on the development and characterization of relatively novel edible films from Persian gum (PG) under different concentrations of glycerol and emulsified oil droplets. At 0.3% of glycerol, PG films were highly brittle for studying their mechanical properties. Higher concentrations of glycerol increased the ductility of films. The increase of oil droplet concentrations resulted in a reduction in the tensile strength, whereas, elongation at break increased. Incorporating the emulsified oil droplets resulted in a significant reduction of water solubility, swelling ability, and water vapor permeability of films. The presence of glycerol and emulsified oil droplets within the film matrix was confirmed by FTIR spectroscopy. SEM micrographs revealed that the plasticized PG films had a uniform microstructure, while, incorporating emulsified oil droplets led to relatively rough microstructure. In conclusion, PG films containing 0.9% glycerol and 1% emulsified oil droplets had desirable properties, which can be exploited for food packaging.