Enhanced lithium host performance of multi-walled carbon nanotubes through acidic functionalization for lithium-sulfur batteries.

Carbon nanotubes (CNTs) have been explored as a potential cathode material for lithium-sulfur (Li-S) batteries owing to their unique structure. However, traditional CNTs exhibit poor dispersion properties when preparing electrodes. The non-uniform distribution of the conductive agents hinders the formation of enough sites for sulfur loading, which results in the aggregation of sulfur/Li2S and severe polarization. In this study, we propose the acidic functionalization of CNTs in the cathode structure as a practical solution for mitigating the poor dispersion and polysulfide shuttling in lithium-sulfur batteries. Multiwalled CNTs were functionalized by oxidation through acidic treatment using sulfuric, nitric, and mixed acids. The cathode prepared with a mixture of sulfuric and nitric acids showed a coulombic efficiency of 99 % after 100 cycles, with a discharge capacity of 743 mAh g-1. These findings demonstrate the effectiveness of the acidic functionalization of CNTs as a promising approach for enhancing the electrochemical performance and commercial viability of lithium-sulfur batteries.

Amylase and Cellulase Production from Newly Isolated Bacillus subtilis Using Acid Treated Potato Peel Waste.

Species belonging to the genus Bacillus produce many advantageous extracellular enzymes that have tremendous applications on a commercial scale for the textile, detergent, feed, food, and beverage industries. This study aimed to isolate potent thermo-tolerant amylolytic and cellulolytic bacterium from the local environment. Using the Box-Behnken design of response surface methodology, we further optimized the amylase and cellulase activity. The isolate was identified by 16S rRNA gene sequencing as Bacillus subtilis QY4. This study utilized potato peel waste (PPW) as the biomaterial, which is excessively being dumped in an open environment. Nutritional status of the dried PPW was determined by proximate analysis. All experimental runs were carried out in 250 mL Erlenmeyer flasks containing acid treated PPW as a substrate by the thermos-tolerant Bacillus subtilis QY4 incubated at 37 °C for 72 h of submerged fermentation. Results revealed that the dilute H2SO4 assisted autoclaved treatment favored more amylase production (0.601 IU/mL/min) compared to the acid treatment whereas high cellulase production (1.269 IU/mL/min) was observed in the dilute acid treatment and was found to be very effective compared to the acid assisted autoclaved treatment. The p-value, F-value, and coefficient of determination proved the significance of the model. These results suggest that PPW could be sustainably used to produce enzymes, which offer tremendous applications in various industrial arrays, particularly in biofuel production.

Improving the Mould and Blue-Stain-Resistance of Bamboo through Acidic Hydrolysis.

Bamboo is much more easily attacked by fungus compared with wood, resulting in shorter service life and higher loss in storage and transportation. It has been long accepted that the high content of starch and sugars in bamboo is mainly responsible for its low mould resistance. In this paper, acetic acid, propionic acid, oxalic acid, citric acid, and hydrochloric acid were adopted to hydrothermally hydrolyze the starch in bamboo, with the aims to investigate their respective effect on the mould and blue-stain resistance of bamboo, and the optimized citric acid in different concentrations were studied. The starch content, glucose yields, weight loss, and colour changes of solid bamboo caused by the different acidic hydrolysis were also compared. The results indicated that weak acidic hydrolysis treatment was capable of improving mould-resistant of bamboo. The mould resistance increased with the increased concentration of citric acid. Bamboo treated with citric acid in the concentration of 10% could reduce the infected area ranging to 10-17%, the growth rating of which could reach 1 resistance. The content of soluble sugar and starch remained in bamboo decreased significantly from 43 mg/g to 31 mg/g and 46 mg/g to 23 mg/g, respectively, when the citric acid concentration varied from 4% to 10%. Citric acid treatments of 10% also caused a greatest surface colour change and weight loss. The results in this study demonstrated citric acid treatment can effectively reduce the starch grain and soluble sugars content and improve mould resistance of bamboo, which can be attributed to the reduction of starch grain and soluble carbohydrates (such as glucose, fructose, and sucrose, etc.) in bamboo.

An approach to change the basic polymer composition of the milled Fomes fomentarius fruiting bodies.

BACKGROUND: Chitin and its derivative chitosan are readily exploited, especially in food, cosmetic, pharmaceutical, biomedical, chemical, and textile industries. The biopolymers are currently recovered from the crustacean shells after purification from the large amount of proteins and minerals. The key problems are centered around a lot of chemical waste and allergenic potential of the heat-stable remaining proteins. Fungi can be considered as an alternative eco-friendlier source of the chitin and chitosan due to the lower level of inorganic materials and absence of the allergenic proteins. RESULTS: The work presents a new chemical assay to change the composition of the milled Fomes fomentarius fruiting bodies. A gradual 13-fold increase of the chitin amount accompanied by 14-fold decrease of the glucan content was obtained after repetitive alkali-acidic treatment. Raw material contained mainly chitin with 30% degree of deacetylation. After the first and second alkali treatment, the polymer was defined as chitosan with comparable amounts of N-acetyl-D-glucosamine and D-glucosamine units. The last treated samples showed an increase of the chitin amount to 80%, along with typical for the natural tinder fibers degree of deacetylation and three-dimensional fibrous hollow structure. CONCLUSIONS: A new approach allowed a gradual enrichment of the pulverized Fomes fomentarius fruiting bodies with chitin or chitosan, depending on the extraction conditions. High stability and fibrous structure of the fungal cell walls with a drastically increased chitin ratio let us suggest a possibility of the targeted production of the chitin-enriched fungal material biotechnologically under eco-friendly conditions.

Data about modification of structural and physicochemical properties of palm kernel expeller dietary fibres with carboxymethylation, acidic treatment, hydroxypropylation and enzymatic hydrolysis combined with heating.

The data presented in this article are related to the research article entitled "Effects of carboxymethylation, acidic treatment, hydroxypropylation and enzymatic hydrolysis combined with heating on structural and physicochemical properties of palm kernel expeller dietary fibres." This article describes the effects of carboxymethylation, acidic treatment, hydroxypropylation and enzymatic hydrolysis combined with heating on the structural and physicochemical properties of palm kernel expeller dietary fibres (PKEDF). Our data is made publicly available to the potential re-use of palm kernel expeller in food and other industries. Moreover, this dataset provides a reference about how to improve physicochemical and functional properties of dietary fiber.

Surface modification of α-chitin using an acidic treatment followed by ultrasonication: Measurements of their sorption properties.

The biopolymer α-chitin is a promising raw source that can be used as a low-cost material for environmental applications. Nevertheless, its low surface properties and high crystallinity limit its use. Recent developments include surface modification as one of the most promising strategies for the application of α-chitin. To this end, we used an acidic treatment, followed by ultrasonication, to modify the α-chitin surface and improve its sorption characteristics to achieve the above goal. Structural analysis and measurement of the physicochemical properties (chemical structure and thermal degradation) of α-chitin, before and after surface modification, indicated no significant changes. However, specific surface area, morphology, surface charge, crystallinity and study of the sorption of methylene blue (MB) from aqueous solution demonstrated surface modification. It was established that the SBET of modified α-chitin increased to 110.7 m2/g and the crystallinity index decreased to 48%. Interestingly, the modified α-chitin could easily adsorb organic dye from an aqueous solution. The experimental adsorption capacity of the resulting α-chitin after surface modification reached the value of about 95 mg/g.

Acidic Pre-Conditioning Enhances the Stem Cell Phenotype of Human Bone Marrow Stem/Progenitor Cells.

A deeper understanding of the detailed mechanism of in vivo tissue healing is necessary for the development of novel regenerative therapies. Among several external factors, environmental pH is one of the crucial parameters that greatly affects enzyme activity and cellular biochemical reactions involving tissue repair and homeostasis. In this study, in order to analyze the microenvironmental conditions during bone healing, we first measured the pH in vivo at the bone healing site using a high-resolution fiber optic pH microsensor directly in femur defects and tooth extraction sockets. The pH was shown to decrease from physiological 7.4 to 6.8 during the initial two days of healing (inflammatory phase). In the same initial stages of the inflammatory phase of the bone healing process, mesenchymal stem cells (MSCs) are known to migrate to the healing site to contribute to tissue repair. Therefore, we investigated the effect of a short-term acidic (pH 6.8) pre-treatment on the stemness of bone marrow-derived MSCs (BMSCs). Interestingly, the results showed that pre-treatment of BMSCs with acidic pH enhances the expression of stem cell markers (OCT-4, NANOG, SSEA-4), as well as cell viability and proliferation. On the other hand, acidic pH decreased BMSC migration ability. These results indicate that acidic pH during the initial stages of bone healing is important to enhance the stem cell properties of BMSCs. These findings may enable the development of novel methods for optimization of stem cell function towards tissue engineering or regenerative medicine.

Low pH treatment of starch industry effluent with bacteria from leaf debris for methane production.

Cornstarch industry generates a huge amount of acidic effluent, that is, 5-11 M3 /Mt grinding, with a high load of chemical oxygen demand, 6000-19000 mg/L. The acidic effluent requires neutralization making the treatment process expensive. Methanogenesis under the acidic environment (pH 5-5.5) can reduce the cost of operation as well as treatment time. This research focuses on the evaluation of the optimum condition of COD reduction and methane generation simultaneously from leaf debris sludge using Box-Behnken model. Three 1 L bioreactors were seeded with 5000-10000 mg/L inoculum and operated at different pH 4.0-7.0 for 72 hr up to 10 cycles. The production of methane was found maximum 2980 ml after treating the wastewater from the starch industry at pH 5.57 and 9612.9 mg biomass load at 62.4 hr. The high reduction rate of around 97% shows there is ample opportunity for further research on low pH treatment of waste along with recovery as methane. PRACTITIONER POINTS: The low pH tolerant methanogenic bacteria are promising and are isolable from various natural resources. The low pH tolerant methanogens was able to remove 97% COD from starch industry effluent at pH 5.57. The recovery of methane was 2980 ml from 9612 mg/L COD which is at per with present treatment system thus provides cost effective alternatives.

Data on the effects of cellulase hydrolysis, acid treatment and particle size distribution on physicochemical and functional properties of coconut (cocos nucifera L) cake dietary fibres.

The data presented in this article are related to the research article entitled "Physicochemical and functional properties of coconut (Cocos nucifera L) cake dietary fibres: Effects of cellulase hydrolysis, acid treatment and particle size distribution" [1]. This article describes the effect of acidic treatment, cellulase hydrolysis and particle size distribution on the monosaccharide composition, X-ray diffraction, Fourier-transformed infrared and spectroscopy surface area of coconut cake dietary fiber. The field data set is made publicly available to the potential re-use of coconut cake or other plants by-products.

Physicochemical and functional properties of coconut (Cocos nucifera L) cake dietary fibres: Effects of cellulase hydrolysis, acid treatment and particle size distribution.

Effects of cellulase hydrolysis, acid treatment and particle size distribution on the structure, physicochemical and functional properties of coconut cake dietary fiber (DCCDF) were studied. Results showed that both the cellulase hydrolysis and acid treatment contributed to the structural modification of DCCDF as evident from XRD, FT-IR and SEM analysis. Moreover, the cellulase hydrolysis enhanced soluble carbohydrate content, water holding capacity (WHC) and swelling capacity (WSC), α-amylase inhibition activity (α-AAIR), glucose dialysis retardation index (GDRI) and cation-exchange capacity (CEC) of DCCDF; but it had undesirable effects on colour, oil holding capacity (OHC) and emulsifying capacity (EC). On other hand, acid treatment decreased the WHC, WSC and GDRI, but improved the colour, CEC, OHC and emulsion stability of DCCDF. Furthermore, the WHC, WSC and EC of DCCDF increased as the particle size reduced from 250 to 167 µm, while the GDRI, OHC, α-AAIR and emulsion stability decreased with decreasing particle size.

Effects of Limited Hydrolysis and High-Pressure Homogenization on Functional Properties of Oyster Protein Isolates.

In this study, the effects of limited hydrolysis and/or high-pressure homogenization (HPH) treatment in acid conditions on the functional properties of oyster protein isolates (OPI) were studied. Protein solubility, surface hydrophobicity, particle size distribution, zeta potential, foaming, and emulsifying properties were evaluated. The results showed that acid treatment led to the dissociation and unfolding of OPI. Subsequent treatment such as limited proteolysis, HPH, and their combination remarkably improved the functional properties of OPI. Acid treatment produced flexible aggregates, as well as reduced particle size and solubility. On the contrary, limited hydrolysis increased the solubility of OPI. Furthermore, HPH enhanced the effectiveness of the above treatments. The emulsifying and foaming properties of acid- or hydrolysis-treated OPI significantly improved. In conclusion, a combination of acid treatment, limited proteolysis, and HPH improved the functional properties of OPI. The improvements in the functional properties of OPI could potentiate the use of oyster protein and its hydrolysates in the food industry.