Lauric acid

Methanol (Optima grade), formic acid (Optima grade), ammonium acetate, hexane, acetonitrile, and ammonium hydroxide were purchased from Fisher Scientific (Fair Lawn, NJ, USA). Oxalyl chloride, oleic acid, erucic acid, petroselaidic acid, heptane HPLC grade, methyl-tert-butyl-ether HPLC grade, isopropanol HPLC grade, acetic acid, and anhydrous dichloromethane were from Sigma Aldrich (St Louis, MO, USA). N, N-dimethylformamide, heptadecanoic acid, and eicosanoic acid were purchased from Aldrich Chemical Company (Milwaukee, WI, USA). Lauric acid, myristic acid, palmitic acid, stearic acid, and docosanoic acid were purchased from Acros Organics (New Jersey, USA). Elaidic acid was from MP Biomedical Inc. (Solon, OH, USA) and linoleamide was purchased from Enzo Life Sciences (Ann Arbor, MI, USA). Stearoyl ethanolamine, oleoylglycine, linoleoylglycine, palmitoylglycine, arachidonoylglycine, and arachidoylglycine were purchased from Cayman Chemicals (Ann Arbor, MI, USA). 1 monopalmitoyl-rac-glycerol (MAG) and tristearin (TAG) were from Sigma (St. Louis, MO) 99% purity and 1,2-dipalmitoyl-rac-glycerol (DAG) was from MP Biomedicals (Solon, Ohio).

As previously reported [19 , 20 ], fatty acids and PLL were used to synthesize fatty acid-PLLs. The saturated fatty acids used were caproic acid (C₆, Sigma-Aldrich), caprylic acid (C₈, Acros Organics), capric acid (C₁₀, Sigma-Aldrich), lauric acid (C₁₂, Acros Organics), myristic acid (C₁₄, Acros Organics), and palmitic acid (C₁₆, Acros Organics), whereas the unsaturated fatty acids used were palmitoleic acid (C_16:1, Fluka), oleic acid (C_18:1, Sigma-Aldrich), and linoleic acid (C_18:2, Sigma-Aldrich). The cationic α-PLL (Alamanda Polymers; molecular mass around 21,000 Da) is a polypeptide composed of repeated structural units of 100 lysine residues and PLL was analyzed by gas chromatography and nuclear magnetic resonance for molecular mass determination and polydispersity index.
Each fatty acid was activated by ethyl chloroformate (ECF), which acts as a coupling agent by activating the carboxylic group of the fatty acids. The intermediate compound was linked to the ε-amine group of the lysine residue through amide-bond formation [21 (link)]. This was then purified by dialysis in buffer solutions and lyophilized for analysis. Thus, the final compounds were called fatty acid-PLLs. For example, lauric acid linked to PLL was called lauryl-PLL (see Figure 1).

Paraffin (P), palmitic acid (PA), and stearic acid (SA) were acquired from Merck Chemical, Aldrich, and TEKKIM, respectively, while amyristic acid (MA) and lauric acid were obtained (LA) from Acros Organics. Molecular and structural formulas of fatty acids are summarized in Table 1. Figure 1 shows chemical structures of the fatty acids and image of the PCMs used in this study. Epoxy and epoxy hardener behave as the auxiliary.
The ELT rubber powder (also can be called as tire rubber powder, rubber powder or regenerated tire rubber) provided from UN-SAL (Turkey) was used as a composite matrix. The properties of the ELT rubber powder sample as indicated in the certificate analysis of the products are presented in Table 2.
The particle size distribution analyses of ELT rubber powder used in this study were determined by laser diffraction particle size analyser (Malvern-Mastersizer 3000). According to the particle size distribution analyses presented in Figure 2, the ELT rubber powder has a median grain size (d50) of 381μm and d90 value of 717μm.

To synthesize ⁶⁴Cu-incorporated iron oxide (⁶⁴Cu-IO) NPs, we purchased the reagents acetylacetone, sodium acetate, copper chloride, benzyl ether, iron acetylacetonate, lauric acid, dodecylamine, cyclohexane, ammonia hydroxide, and tetraethylorthosilicate from Alfa Aesar. In addition, reagents 1,2-hexadicanediol and igepal CO-520 were purchased from Sigma Aldrich (Burlington, MA, USA). ⁶⁴Cu was supplied by Korea Institute of Radiological & Medical Sciences.