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Nanoparticles — Preparation and Applications
Published in Max Donbrow, Microcapsules and Nanoparticles in Medicine and Pharmacy, 2020
More recently, attempts have been made to use the process of polymerization in an organic continuous phase for the production of polyalkylcyanoacrylate nanoparticles. Poly-methylcyanoacrylate,49-52 polyethylcyanoacrylate,49,52 and polybutylcyanoacrylate49,52 nanoparticles were produced using cyclohexane, isooctane, chloroform, dichlormethane, n-pentane, rc-hexane, butanol, toluol, castor oil, and/or isopropyl myristate as the organic phase. Polysorbate 2049 and 81,52 Arlacel A®,49 sodium dioctylsulfosuccinate,51 poly-hydroxyethylen-4-laurylether,52 sorbitan monolaurate,52 sorbitan monopalmitate,52 sorbitan monostearate,52 sorbitan trioleate,50 and Cremophor RH 40®50 were used as the emulsifiers. The drugs used were doxorubicin,49 fluorescein,49 triamcinolone,50 pilocarpine,52 and timolol.52 The drugs are dissolved in a small amount of water that is solubilized by the surfactants in the organic phase. For this solubilization, higher amounts of surfactants are required than by polymerization in an aqueous phase. The monomers are then either added directly to52 or dissolved in organic solvents.49,51 Upon contact of the monomer molecules with the solubilized water molecules, the polymerization is initiated (Figure 1).
1,4-Dioxane Chemistry, Uses, and Occurrence
Published in Thomas K.G. Mohr, William H. DiGuiseppi, Janet K. Anderson, James W. Hatton, Jeremy Bishop, Barrie Selcoe, William B. Kappleman, Environmental Investigation and Remediation, 2020
Food additives have been regulated in the United States and Europe for their 1,4-dioxane content. The U.S. Food Chemicals Codex restricts residual 1,4-dioxane content in polysorbates to 10 mg/kg. Polysorbate 60 [polyoxyethylene (20) sorbitan monostearate] is an emulsifier used in ice cream, frozen custard, ice milk, fruit sherbet, and other frozen desserts. Polysorbate 60 is used alone or in combination with polysorbate 65 and/or polysorbate 80. Polysorbates have been found to contain trace levels of 1,4-dioxane and ethylene oxide as impurities, which result from the production processes used for polysorbates (FDA, 1999). Polysorbate 60 and polysorbate 80, which are produced from the polymerization of polyoxyethylene, have historically been found to contain 1,4-dioxane (Birkel et al., 1979). Levels of 1,4-dioxane in these compounds have been reported to range from 5 to 6 ppm (mg/L) (ATSDR, 2004).
Polyethylene Wax: Uses, Characterization, and Identification
Published in Andreea Irina Barzic, Neha Kanwar Rawat, A. K. Haghi, Imidic Polymers and Green Polymer Chemistry, 2021
Senem Yetgin, Mehmet Gonen, Sevdiye Atakul Savrik, Devrim Balkose
The present study aims the characterization and identification of a commercial PE wax which is used for pigment masterbatch preparation by comparing with paraffin wax, sorbitan monostearate (Span 60), and myristic acid.
Microcapsule synthesis and evaluation on fatigue and healing of microcapsule-based asphalt by the entropy and TOPSIS method
Published in International Journal of Pavement Engineering, 2022
Yongdan Wang, Ruixin Zhai, Bowei Sun, Jingwen Liu, Peiwen Hao
Raw materials for microcapsules’ synthesis include: urea and formaldehyde solution for shell, triethanolamine and citric acid as the initiator, OP-10, SDBS (sodium dodecyl benzene sulphonate), SDS (sodium dodecyl sulphate), Span-60 as emulsifier alternatives. OP-10 (octylphenol polyoxyethylene ether-10) is a type of hydrophilic emulsifier with favourable wettability, diffusion, anti-static electricity. Span-60 (sorbitan monostearate) is one of the non-ionic surfactants that are used as emulsifying agents in the preparation of emulsions, creams, and ointments for pharmaceutical and cosmetic use. The core applied for microcapsules is refined waste engine oil (rWEO), which is obtained from Xi'an Boyuan waste oil recovery Co., Ltd. The basic properties of rWEO are given in Table 1. Asphalt is from SK energy CO., Ltd. The basic properties are given in Table 2.