Journal of Composites and Biodegradable Polymers

Development of Dextran Coated Zinc Oxide Nanoparticles with Antimicrobial Properties

Wed, 17 Apr 2024 00:00:00 +0000

Dextran coated zinc oxide nanoparticles with various zinc concentration have been developed in this study. Various characterization techniques were used in order to study the physical-chemical properties of the obtained samples. The structure of the samples was investigated using X-Ray diffraction (XRD), while the morphology was studied by scanning electron microscopy (SEM). Information regarding the porosity of the samples were obtained with the aid of Brunauer-Emmett-Teller (BET) method. The results of the physico-chemical characterization depicted the obtaining of a nanocomposite with homogenous and uniform morphology. Furthermore, the antimicrobial activity of the samples was also investigated against Gram-positive bacterial strains (Staphylococcus aureus 0364, Enterococcus faecalis ATCC 29212 and Bacillus subtilis), Gram-negative bacterial strains (Pseudomonas aeruginosa 1397, Escherichia Coli ATCC 259220 and against fungal strain Candida albicans ATCC 10231. The results of the antimicrobial assay showed that the nanocomposites exhibited good inhibitory effects against all the tested microorganisms making them suitable candidates for the further development of antimicrobial agents for biomedical applications.

Recovery of Phosphors by Beneficiation Technology

Jing Guo, Bing Li, Hao Peng, Changyuan Tao — Wed, 07 Aug 2024 00:00:00 +0000

Phosphorous is indispensable in the phosphoric acid industry, fertilizers, and elemental phosphorus production due to its high economic importance. The way to successfully upgrade phosphate ore was based on a full understanding of its mineralogy, mineral surface properties, mineral distribution and liberation. Most phosphate ores are not suitable for direct use in the acidulation process because they have relatively low P₂O₅ contents and generally contain many impurities. Thus, low-grade phosphate ores must be pretreated to reach a suitable phosphate concentrate by the following beneficiation techniques: flotation, attrition scrubbing and deslming, electrostatic separations, magnetic separation, gravity separation and calcination. Flotation was predominantly used for the beneficiation of phosphate ores, while calcination could be feasibly used when the fuel energy cost was low and the water source was limited. The chemical composition and texture of phosphate ores should be considered when applying attrition scrubbing and desliming, magnetic separation and gravity separation. Commonly, some of the above technologies should be combined to obtain excellent results.

Recent Advances in Carbon Nanotube-Modified Polylactide

Tao Qiang, Shibo Jia — Mon, 12 Aug 2024 00:00:00 +0000

Polylactide (PLA) has been regarded as one of the most promising bio-based, environmentally-friendly polymers. The products derived from PLA will degrade into CO2 and H2 O ultimately after being wastes. To this extent, PLA is the really sustainable synthetic polymers, due to its nature-to-nature loop within life cycle. However, inherent brittleness, poor heat resistance, slow crystallization rate and high cost, have limited pure PLA and its composites’ potential applications. Carbon nanotubes (CNT) is one kinds of one-dimensional nano-materials with hollow structures composed of only hybrid sp² C-C bonds. CNT is identified as the most preferred candidate for space elevators, due to its excellent mechanical properties and electrical conductivity. CNT/PLA blends will exert synergistic effects of their individual component, bring breakthroughs in their structures and various properties, and open up potential application scenarios for the resultant composite materials. In this review, recent advances on fabrication methods, structure manipulation, property optimization and application scenarios of CNT/PLA composites were summarized. Especially, the effects of CNT content and pretreatment methods on the microstructures and properties of the resultant PLA composites were focused on in this review. Also, future prospective of CNT/PLA composite materials were addressed.

pH-Sensitive Biodegradability of Poly(Maleic acid-co-Malic acid-coButane-1,4-diol-co-Adipic acid) for Smart Release of Fertilizers

Wed, 20 Nov 2024 00:00:00 +0000

Poly(Maleic acid-co-Malic acid-co-Butane-1,4-diol-co-Adipic acid) was synthesized in xylene medium using Dean-Stark apparatus. Corresponding monomers were taken in stoichiometric ratios. A trace amount of anhydrous ferric chloride was added as catalyst. The reaction temperature and time were 135-140^°C and 5 hours respectively. The synthesized co-polyester was characterized by its solubility test in common organic solvents, molecular weight, FTIR-spectrum, TGA, hydrolytic test and soil burial biodegradability tests. The end group analysis and viscosity methods were used for molecular weight determination. From the hydrolytic degradation study it was found that the polyester sample remained almost intact in the acid medium but gradually degraded in the basic medium. Soil burial test reveals that the co-polyester is almost mixed with the soil within two months which indicates its biodegradability in the soil. Because of these special characteristics this co-polyester could be a future endeavor for smart release of fertilizers.