【正文】 筆者認(rèn)為， 從研究結(jié)果可以得出結(jié)論，較長 的 疏水鏈和較短的聚環(huán)氧乙烷鏈增加了緩蝕劑緩蝕效率。 . Corrosion inhibition mechanism The mechanism of the inhibition processes of the corrosion inhibitors under consideration is mainly the adsorption one. The process of adsorption is governed by different parameters depend almost on the chemical structure of these inhibitors. The adsorption process is occurred either physically or chemically. Fig. 6 indicates that the inhibition efficiency increased by increasing the doses of the used inhibitors until the maximum η values at 100 ppm. Then, the efficiency decreased gradually by increasing the inhibitor concentration to 200 or 400 ppm. That indicates the formation of neat layer of inhibitors at the metal/solution interface at the lower concentrations. The density of this layer increases by increasing the dose to 100 ppm. The decrease inη at higher doses indicates that the adsorption is not in successive layers due to the formation of the micelles at higher concentrations [19]. That conclusion can be interpreted from Fig. 7. The formation of only one Sshape proves the formation of one layer of the inhibitor molecules at the metal surface. On conclusion, from the results of the study it could be concluded that longer hydrophobic chains and shorter polyethylene oxide chains increases the corrosion inhibition efficiencies of the corrosion inhibitors. Also, it can be concluded that the inhibition mechanism is a physical one and there is a critical concentration for the inhibitors to produce the maximum efficiency. . 緩蝕機(jī)理 本文認(rèn)為緩蝕劑的抑制腐蝕過程的機(jī)理主要是在吸附作用。 很顯然，緩蝕劑 在較高劑量（ 400 ppm） 時(shí) η出現(xiàn) 了 最低值。因此，緩蝕劑分子趨向于遷移到大部分水介質(zhì)，從而降低相界面的吸附趨勢。 此外， Table 2也說明每個(gè)緩蝕劑分子在相界面的平均面積 (Amin)隨著它們鏈上亞甲基的增加而增加。那種行為能別解釋為兩個(gè)因素。這表明，這些兩親分子的膠束趨勢比吸附趨 勢大。 . Thermodynamics of adsorption and micellization The micellization and adsorption processes of the amphiphile molecules are occurred instantly. But, in mon, one process may be predominating than the other one. The predominance of any of the two processes is governed by the thermodynamic variables of this process. In the investigated amphiphiles, both adsorption and micellization thermodynamic functions were calculated based on the methodology of Rosen [24]and using the surface activity data in Table 2. The free energy changes of micellization and adsorption showed negative sign indicating the spontaneously of the two processes at 25 ?C. Also, Δ Gmic decreased gradually by increasing the hydrophobic chain lengths. But, Δ Gads has slight increase in negativity than Δ Gmic. The maximum depression in Δ Gmic and Δ Gads was observed at ? and kJ/mol for SB2020oleate, respectively. That showed the higher tendency of these amphiphiles towards adsorption rather than micellization. The tendency towards adsorption is refereed to the interaction between the aqueous phases and the hydrophobic chains which pumps the amphiphile molecules to the interface. The presence of these amphiphiles at the interface decreases the different in phase interactions. 膠束的形成和兩親分子的吸附過程是瞬間發(fā) 生的。 臨界膠束濃度值的增大指明在兩親分子和水分子之間形成了氫鍵 (HBs).氫鍵增加了這些兩親分子在空氣 /水界面吸附，這也逐漸增加了臨界膠束濃度值。最大 剩余面積值的計(jì)算表明，從 SB2020decanoate 到 SB2020oleate 增加趨勢，表示表面張力前臨界膠束濃度區(qū)域的斜率范圍。 3. Results and discussion . The surface activity . Effect of hydrophobic chain length (nonpolar chain) Fig. 1 represents the relation between the surface tension and ?log concentration of the synthesized nonionic Schiff base amphiphiles containing similar polyethylene glycol content (n=45 EO units) at 25 ?C. It is clear that the surface tension profile has the characteristics of the nonionic surfactants. That appeared in the relatively higher surface tension values. Also, it could be observed that increasing the number of methylene groups along the hydrophobic chains from 10 to 18 units decreases the critical micelle concentrations gradually [17]. That effect was explained in a previous work [20,21] due to the repulsion occurred between the hydrophobic chains (nonpolar phase) and the water phase (polar phase), which forced the molecules to adsorb at the air– water interface and to micellize in the bulk of their solutions in order to decrease that repulsion. While, the lowest critical micelle concentration was found at base containing PEO2020 and the hydrophobic chains is oleate (Table 2), which referred to the above reasons and also to the unsaturation sites in the oleate chain which increases the repulsion extent. The effectiveness (π cmc) values showed gradual decrease by increasing the hydrophobic chain length indicating the increasing of accumulated surfactant molecules at the interface. The maximum accumulation was indicated by the lowest surface tension depression at the critical micelle concentration and was recorded for SB2020oleate molecules at 44 mN/m . The effectiveness values as well as the maximum surface excess considered as a clear description for the accumulation extent of amphiphiles molecules at the ai