Tenebrio molitor Larvae-Based Magnetic Polyurea Employed as Crude Oil Spill Removal Tool.

Renewable resources constitute an extremely rich and varied set of molecules and polymers produced by natural biological activities. Within the applications of these polymers, a very important application is the use of these materials as a sorber for oils or oil spills. The advantage of these nanocomposites is the fact that they integrate different component materials and their properties into a single component material. They have several applications, ranging from environmental remediation to the development of advanced medical applications. This work proposed using magnetic polyurea composites based on an animal substrate from Tenebrio molitor larvae to perform oil spill clean-up operations under a magnetic field in the presence of 1% and 3% of magnetite to be tested as magnetic crude oil sorber. The obtained materials were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Scanning Differential Calorimetry (DSC), and Low-Field Nuclear Magnetic Resonance (LF-NMR 1H). The sorber material is simple to prepare and inexpensive. The use of magnetite as a magnetic charge allowed for the efficient removal of oil from water with about 28 g of oil per gram of sorber. These results are very promising and encouraging for future environmental recovery studies involving magnetite and sustainable polymers.

Oil Spill Sorber Based on Extrinsically Magnetizable Porous Geopolymer.

Environmental impacts are increasingly due to the human polluting activities. Therefore, there is a need to develop technologies capable of removing contamination and driving the impacted environment as close as possible to its inherent characteristics. One of the major problems still faced is the spill of oil into water. Therefore, to solve the environmental problem, this work shows the use of magnetically modified geopolymer materials as an oil remover from water with a magnet's aid. The results obtained were outstanding since the average intrinsic oil removal capability (IORC) was 150 g/g. The presented IORC is the largest found in the materials produced by our research group, constituting an extremely encouraging result, mainly because of the ease of preparing the magnetic geopolymer system. Furthermore, the low cost of production and the material's capability to be reused as filler of polymer or even cementitious matrices allows us to project that this nanocomposite can be widely used, constituting an economically viable alternative for more efficient environmental recovery processes.

Poly (butylene succinate) and derivative copolymer filled with Dendranthema grandiflora biolarvicide extract.

Dengue is the most important infectious disease in the world and is a severe public health problem. The chikungunya is an arbovirus, in many cases, increased, which is transmitted by the same transmitter dengue vector, Aedes aegypti. The symptoms of both diseases are similar, and infections can be lethal. Although there is no preventive vaccine against any of the two diseases, therefore, it is extremely important to control the mosquito. The eggs of A. aegypti are very resistant and hatch into larvae, which later give rise to mosquitoes in any container with water. Natural plant extracts have come from active substances with larvicidal activity against A. aegypti. However, they tend to be highly hydrophobic and need some strategy to improve its affinity for water. Because of these factors, this research aims to synthesize and characterize polymeric materials with properties suitable for the release of hydrophobic principles with larvicidal action. The synthesized polymers are poly (butylene succinate) (PBS) and PBS block copolymer with polyethylene glycol (PEG). The synthesized polymers were characterized by nuclear magnetic resonance, thermal analysis simultaneous, differential scanning calorimetry, Fourier transform infrared spectroscopy, and diffraction of X-rays analysis. The analysis results showed that the synthesized materials have chemical composition and properties suitable for use in the controlled release of actives substances. Systems were prepared using the Dendranthema grandiflora extract, which has larvicidal activity was incorporated via fusion to polymers, to evaluate its release in aqueous media. The results proved that higher amounts of PEG in the copolymer chain speed up the delivery of the larvicidal extract. Besides that, the larvicidal extract concentration required to cause death larvae of A. aegypti was achieved from the first minutes of dissolution tests, indicating that the materials developed are promising tool to fight dengue and chikungunya. This new system is a vital tool for eliminating vectors, potentially contributing to saving millions of lives worldwide.

Biodegradation of Vulcanized SBR: A Comparison between Bacillus subtilis, Pseudomonas aeruginosa and Streptomyces sp.

Rubber residues present harmful impacts on health and environment, besides wasting valuable and huge amounts of rubber. Biological recycling technique is focused here to minimize this problem. A comparison of the biodegradation effect caused by Bacillus subtilis, Pseudomonas aeruginosa, and Streptomyces sp., separately, on vulcanized SBR-rubber during 4 weeks is reported. The surface and molecular analyses were studied by FTIR-ATR, TGA, DSC, TC and SEM/EDS, in addition to the contact angle and crosslinking tests. B. subtilis, P. aeruginosa, and Streptomyces sp. evoked after 4 weeks a loss in v-SBR crosslinks by 17.15, 10.68 and 43.39% and also in the contact angle with water by 14.10, 12.86 and 15.71%, respectively., if compared to Control samples. FTIR findings indicate that the polymeric chain has been partially consumed causing C-C bonds scission indicating the biodegradation and bio-devulcanization phenomena. The bacterial strains caused a carbon loss by 9.15, 5.97 and 4.55% after one week and 16.09, 16.79 and 18.13% after four weeks for B. subtilis, P. aeruginosa, and Streptomyces sp. mediums, respectively. DSC and EDS results are also promising and highlighting Streptomyces sp. strain as the most effective biodegradative one as an alternative and natural mean of degrading vulcanized rubber residues.

The biodegradative effect of Tenebrio molitor Linnaeus larvae on vulcanized SBR and tire crumb.

The overall world consumption rate of rubber tends to increase by an average of 2.8% per year in the period between 2017 and 2025. Rubber residues represent a severe problem to both health and environment due to their cross-linked structure that offers a prolonged degradation rate. A good solution to eliminate this problem is recycling and recovery, aiming at the production of new materials. The tire crumb can be recycled by chemical/biological recovery, where the elastomer is devulcanized, or by physical recovery, where the three-dimensional network is transformed into small fragments. In this study, we investigated the bio-degradation effect caused by Mealworms (the larvae of Tenebrio molitor Linnaeus) on vulcanized SBR-rubber and tire crumb as a desulphurization method. The surface modifications of both rubbers were studied by instrumental techniques: FTIR-ATR, TGA, XRD, and SEM. The cross-linking degree of the rubber was determined via circular condensation method. The obtained results show that the Tenebrio molitor could survive after three weeks of direct contact with SBR-rubber and tire crumb as the only alimentation. There was a declining effect of cross-linking degree by increasing the contact time between the rubbers and larvae. The FTIR results indicate surface/chemical modifications of the rubbers and the SEM results show the free sulfur after it was released in the form of sulfur flower-like. Also, the TGA results highlight a difference in the degrading behavior and residues of the treated and non-treated rubbers. Therefore, the reported results were promising, demonstrating the biodegradation effect caused by the Tenebrio molitor mealworms, highlighting an alternative and natural mean of degrading vulcanized rubber residues.