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Evaluation of foamed bitumen efficiency in warm asphalt mixtures recycling
Published in Cândida Vilarinho, Fernando Castro, Mário Russo, Wastes: Solutions, Treatments and Opportunities, 2015
Cândida Vilarinho, Fernando Castro, Mário Russo
Therefore, the alkaline hydrolysis emerges as a waste treatment option, mainly because it is able to significantly reduce the volume of animal wastes and to produce sterile by-products (Tracker, 2004) which can be used for soil fertilization (Kalambura et al., 2011). The efficacy of alkaline hydrolysis on the destruction of tissue wastes, including anatomical parts, organs, placenta, blood, body fluids, specimens, human cadavers and animal carcasses has been proven in some studies (Tracker, 2004). However, conditions for destruction are reported to be 150∘C with a time of contact between three and eight hours. This work intended to study the minimal conditions for destruction of animal tissues. The behavior of animal tissues, such as pork and beef, when treated by alkaline hydrolysis was studied. The efficiency of the treatment was assessed by determination of weight losses on the materials and characterization of total organic carbon (TOC), chemical oxygen demand (COD) and biochemical oxygen demand after five days (BOD 5 ) in the effluents resulting from the alkaline hydrolysis treatment. MATERIALS AND METHODS
Fabrication and characterization of silk microfiber-reinforced methacrylated gelatin hydrogel with turnable properties
Published in Journal of Biomaterials Science, Polymer Edition, 2018
Wenqian Xiao, Yunfei Tan, Jiale Li, ChengFu Gu, Hang Li, Bo Li, Xiaoling Liao
In order to fabricate the fiber-reinforced hydrogel in this study, we first successfully prepared silk microfibers of three different lengths through a modified alkaline hydrolysis process. Moreover, a sieve method was used to solve the fiber length heterogeneity issues caused by this approach. Figure 2A–2C exihibited the microscopic morphology of the prepared short fibers, medium fibers, and long fibers, respectively. As shown, the length distributions of each kind of fiber are uniform, the length of the obtained fibers analyzed by ImageJ software were 0.15 ± 0.04 mm, 0.49 ± 0.07 mm, and 2.03 ± 0.32 mm, respectively. Statistical analysis revealed that there were remarkable differences in fiber length (p < 0.001) between all groups (Figure 2D). In the alkaline hydrolysis process, the NaOH hydrolyses amide bonds in silk fibers into a carboxylic acid and an amine. Based on previous research [27,28,34], we determined that the amount of NaOH, external heating, and alkaline hydrolysis time are three critical factors that affect the lengths of the resulting microfibers. Increasing external heating is particularly more conducive to destroying the hydrogen bonds in the crystalline regions of silk and greatly shortens the preparation time [25,27]. In our experiment, all the fibers were prepared within two minutes, confirming this method was fast and efficient to obtain the uniform silk micro-fiber. Particularly, tailoring the process parameters allowed us to increase the range of fabricated microfiber sizes (to three different groups) for further hydrogel reinforcement studies.
Modification of polyester fabrics with Zn2SnO4 nanorods for superior self-cleaning, UV-protection and antibacterial performance
Published in The Journal of The Textile Institute, 2023
In the current study, the zinc stannate nanorods was used to develop multifunctional polyester fabrics. The effect of alkaline hydrolysis of polyester fabric with sodium hydroxide in the synthesis of Zn2SnO4 nanorods was explored. SEM images, XRD and EDS patterns established the formation of the zinc stannate nanorods on the polyester fabric surface. Functional characteristics of the Zn2SnO4 treated polyester including self-cleaning, antibacterial and ultraviolet (UV) protection properties were superior compared to the treated polyester with zin oxide. It is expected the zinc stannate-treated fabrics can be used in medical textiles, protective garments, sportswear and smart textiles for healthcare benefits.
Ultrasound-Assisted Alkaline Hydrolysis of Waste Poly(Ethylene Terephthalate) in Aqueous and Non-aqueous Media at Low Temperature
Published in Indian Chemical Engineer, 2018
Chandrakant Sharad Bhogle, Aniruddha Bhalchandra Pandit
Usually, alkaline hydrolysis of PET is carried out in aqueous alkaline solution by the use of various alkalis such as sodium hydroxide, potassium hydroxide or aqueous ammonia solution. The conditions of hydrolysis to occur are quite severe in some of the studies: temperature – 250°C; pressure – 800 psi. Enzymatic hydrolysis of PET was studied by many researchers using enzymes such as cutinase [4–8], lipase [4, 6, 8, 9] and esterase [4, 10], but the rate of enzymatic hydrolysis was very slow. Recently, phase transfer catalysts (PTC) such as quaternary ammonium and phosphonium salts were used to carry out the depolymerization reaction of PET at atmospheric pressure and temperature below 150°C [11–16].