中英文對照翻譯---表面活性

1、<p>　　關(guān)鍵詞：非離子表面活性劑 希夫堿 吸附 表面張力 緩蝕 緩蝕速率 緩蝕效率</p><p>　　a b s t r a c t</p><p>　　A novel series of self-assembled nonionic Schiff base amphiphiles was synthesized and their chemical structures

2、 were confirmed using elemental analysis, FTIR spectroscopy and 1H NMR spectra. The surface activities of these amphiphiles were determined based on the data of surface and interfacial tension, critical micelle concentr

3、ation, effectiveness, efficiency, maximum surface excess and minimum surface area. Thermodynamics of adsorption and micellization processes of these amphiphiles in their</p><p><b>　　摘要</b></p&

4、gt;<p>　　一種新型系列自組裝非離子型兩親Schiff堿被合成，它們的化學(xué)結(jié)構(gòu)用元素分析法確定，紅外光譜和核磁共振氫譜。這些兩親分子的表面活性的確定要基于表面張力和界面張力、臨界膠束濃度，效果，效率，最大和最小表面積的數(shù)據(jù)。他們的方案也計算了吸附熱力學(xué)和這些兩親分子膠束化過程。表面狀況數(shù)據(jù)和熱力學(xué)數(shù)據(jù)顯示它們對在界面吸附有較大的傾向。 用失重法和析氫技術(shù)評價不同劑量（400-10ppm）的合成的兩親分子作為鋁（3S

5、R）的緩蝕劑在酸性介質(zhì)（4N HCl）中的緩蝕效果。腐蝕實驗表明合成的非離子型席夫堿是有效的緩蝕劑。表面活性和緩蝕性能與緩蝕劑的化學(xué)結(jié)構(gòu)有關(guān)。</p><p>　　1. Introduction</p><p>　　Ferrous, nonferrous metals and their alloys are extensively used in industry. To remove

6、unwanted scale and salt deposits or mill scales formed during manufacture, metals are immersed in acid solutions, which are known as an acid pickling bath. After the scale is removed, the metal may be subjected to attack

7、 by the acids. In order to reduce the degree of metal attack and rate of consumption of the acid, corrosion inhibitors are added to the pickling solutions Hydrochloric and sulphuric acids are </p><p><b&g

8、t;　　概括</b></p><p>　　黑色金屬，有色金屬及其合金被廣泛應(yīng)用于工業(yè)中。要除去金屬在生產(chǎn)過程中形成的未知污垢和鹽垢或銑垢，金屬要浸泡在酸液中，也就是我們常說的酸洗浴。除去垢之后，金屬可能會受到酸的腐蝕。為了降低金屬受腐蝕的程度和酸液的消耗速率，我們需要在酸洗液中添加緩蝕劑。鹽酸和硫酸是酸洗浴中最常用的酸[1,2].很多商業(yè)緩蝕劑組成中都含有醛和胺 [3,4]。選擇緩蝕劑要考慮的兩個因素

9、是：一，它們能夠很方便的由相關(guān)原料合成；二，它們含有帶電子的苯環(huán)或者是有電負(fù)性原子，如含有芳香環(huán)的席夫堿[5,6]。據(jù)報道，席夫堿類緩蝕劑對鐵、銅鋁都有效緩蝕效果[7–9]。這些物質(zhì)通常能有效地吸附在金屬表面。吸附取決于金屬的性質(zhì)和緩蝕劑的化學(xué)結(jié)構(gòu)[10]。自組裝單層膜是緩蝕的一種便捷方法，膜的化學(xué)組成和自組裝單分子膜的厚度可通過設(shè)計吸附劑的合成實現(xiàn)。一些研究機(jī)構(gòu)已經(jīng)開發(fā)了應(yīng)用于實際的自組裝膜緩蝕劑[11–14]。實驗結(jié)果發(fā)現(xiàn)，結(jié)果發(fā)現(xiàn)

10、，含有雜原子化合物的致密自組裝單層能有效阻止某些電化學(xué)過程，從而能夠作為有效的緩蝕劑。在本項目的研究中，不同的自組裝緩蝕劑由含有不同分子量聚乙二醇鏈端基合成的席夫堿制備。表征這些化合物對鋁合金緩蝕效</p><p>　　2. Experimental procedures</p><p>　　2.1. Synthesis of Schiff bases</p><p&g

11、t;　　0.5 mol of anisaldehyde was condensed with 0.5 mol of p-aminobenzoic acid in the presence of 250 mL of ethyl alcohol as a solvent. The reaction mixture was refluxed for 6 h and then left overnight until the product w

12、as precipitated. The product was washed by petroleum ether and recrystallized from ethanol. The final product was dried under vacuum at 40 ?C [15]. The produced Schiff base was denoted as SB and the chemical structure wa

13、s represented in Scheme 1.</p><p>　　Scheme 1. Chemical structure of the synthesized Schiff base.</p><p>　　Scheme 2. Chemical structure of the synthesized nonionic Schiff base.</p><p&g

14、t;<b>　　2.實驗步驟</b></p><p><b>　　2.1.合成席夫堿</b></p><p>　　0.5mol的茴香醛和0.5mol的對氨基苯甲酸以250mL的無水乙醇做溶劑。反應(yīng)混合物回流6小時，放置過夜直到產(chǎn)物沉淀出來。用石油醚洗滌，再用乙醇重結(jié)晶。最終產(chǎn)物在40?C真空干燥。合成的席夫堿記為SB，化學(xué)結(jié)構(gòu)式如方案1表示。&l

15、t;/p><p>　　方案1.合成席夫堿的化學(xué)結(jié)構(gòu)</p><p>　　方案 2. 合成非離子型的席夫堿的化學(xué)結(jié)構(gòu)式</p><p>　　2.2. Synthesis of nonionic Schiff bases amphiphiles</p><p>　　Polyethylene glycol monoalkanoate of differ

16、ent molecular weights (400, 1000, 2000 and/or 3000, where, n = 9, 45 and/or 68) and different alkyl chain lengths (R = 10: decanoate; 16: hexadecanoate 8: octadecanoate and/or oleate) were esterified by the synthesized S

17、chiff base SB in equimolar ratio in xylene as a solvent and p-toluene sulfonic acid (0.01wt.%) as a dehydrating agent [16]. The reaction was continued until complete removal of the water of the reaction. Vacuum distillat

18、ion was performed</p><p>　　2.2. 非離子型兩性席夫堿的合成</p><p>　　等摩爾比的不同分子量的聚乙二醇（400,1000,2000和/或3000 ，n=9.45和/或68）和不同鏈長的單鏈烷烴（R=10：癸酸；16；棕櫚酸；18：硬脂酸和/或油酸）縮合的聚乙二醇酯與已合成的席夫堿在以二甲苯為溶劑，對甲苯磺酸（0.01wt.%）做干燥劑[16] 的條件

19、下進(jìn)行酯化反應(yīng)。反應(yīng)持續(xù)到體系水分完全除去。真空蒸餾除去未反應(yīng)的物料和溶劑，方案2 .記非離子型席夫堿產(chǎn)物為SB-PEG-鏈烷酸（R），列在表1中。</p><p>　　2.3. Structural analysis</p><p>　　The elemental analyses were performed for the synthesized surfactants using

20、Vario Elementar instrument for elemental analysis, Fourier-transform infrared spectrophotometer for FTIR spectra and Bruker model DRX-300 NMR spectrometer with TMS as an internal standard for 1H NMR spectra. The results

21、 were represented in Table 1.</p><p><b>　　2.3. 結(jié)構(gòu)分析</b></p><p>　　用Vario元素分析儀對合成的表面活性劑做元素分析，用傅里葉變換紅外光譜儀做紅外光譜及用布魯克模型的DRX - 300核磁共振以TMS內(nèi)部標(biāo)準(zhǔn)核磁共振光譜。結(jié)果列在表1中。</p><p>　　2.4. Sur

22、face and interfacial tension measurements</p><p>　　Surface tension measurements were made for freshly prepared inhibitors solutions in a concentration range of 0.1–0.0001M/L at 25 ?C using a Du-Nuoy Tensiome

23、ter-Kruss-K100. Also, interfacial tension measurements were made for inhibitors–oil systems [17].</p><p>　　2.4.表面張力和界面張力測定</p><p>　　表面張力的測試是用Du-Nuoy Tensiometer-Kruss-K100在25?C測濃度范圍分布在0.1–0.000

24、1M/L的新制備的緩蝕劑溶液。此外，界面張力測量在緩蝕劑-油的體系中進(jìn)行[17]。</p><p>　　2.5. Weight loss determination</p><p>　　Aluminum coupons of 10cm2 were used for weight loss measurement. Different concentrations of the inhibi

25、tors (400–10 ppm) in 4N HCl solution were used at 25 ?C. Coupons were placed in the corrodent–inhibitor systems and removed at 1 h interval for 4 h. The tested specimens were washed with distilled water and ethanol then

26、dried and weighted. The difference in the weight was taken as the weight loss in mg. The percentage inhibitor efficiency was calculated as [18]</p><p>　　%Efficiency = [Wb ?W / Wb]</p><p>　　Where

27、 Wb and W are the weight loss of aluminum specimens without and with inhibitors, respectively.The corrosion rates were calculated according to the following formula:</p><p>　　Cr (mpy) = KW /ATD</p>&l

28、t;p>　　where K is the constant, A the area, T the time,W the weight loss in mg and D is the density.</p><p>　　2.5. 失重法的測定</p><p>　　用10cm2的鋁片做失重法實驗。4N HCl溶液在25?C下加入不同濃度范圍(400–10 ppm)的緩蝕劑。將鋁片置于

29、腐蝕劑-抑制劑體系中，在1~4小時內(nèi)取出。測試的樣品用蒸餾水和乙醇洗滌后，干燥，稱重。重量的變化就是質(zhì)量損失，用mg表示。緩蝕劑效率百分比的計算方式[18]：</p><p>　　緩蝕效率%=[Wb ?W / Wb] </p><p>　　式中，Wb 和W分別代表鋁片樣本在有緩蝕劑和沒緩蝕劑時的重量損失。</p><p>　　緩蝕速率的計算由下面公式計算：</

30、p><p>　　Cr (mpy) = KW /ATD</p><p>　　式中，K為常數(shù)，A是面積，T是時間，W是質(zhì)量損失mg，D是密度。</p><p>　　2.6. Hydrogen gas evolution technique</p><p>　　In the gas evolution measurement, the corrosio

31、n rates of aluminum were investigated by the hydrogen evolution rate with the inhibitors concentrations of 400, 200, 100, 50, 25 and 10ppm and 4N HCl solution without inhibitors. The hydrogen evolved is a function of the

32、 corrosion reaction and it displaced the fluid in the gasometeric setup, which is read directly. Experiments performed without inhibitors recorded the highest volume of hydrogen gas evolved [19]. The percentage efficienc

33、y was calculat</p><p>　　%Efficiency =[Vb ? V / Vb ]</p><p>　　where Vb and V are the volumes of hydrogen evolved without and with inhibitors, respectively.</p><p><b>　　2.6. 析氫技

34、術(shù)</b></p><p>　　在氣體析出實驗測試中，用氣體的變化速率考察鋁在含加有濃度為400,200,100,50,25和10 ppm緩蝕劑以及沒加緩蝕劑的4N HCl溶液中的腐蝕速率。氫氣的析出速度是腐蝕反應(yīng)速度的反函數(shù)，在氣體定量分析法中用氫氣的析出代替液體的變化，可以直接讀取數(shù)據(jù)。實驗表明沒有加緩蝕劑的氫氣析出體積為最大值[19]。腐蝕速率用下式計算：</p><p>

35、;　　%效率=[Vb ? V / Vb ]</p><p>　　其中，Vb 表示沒加緩蝕劑的氫氣體積，V表示有緩蝕劑的氫氣體積。</p><p>　　3. Results and discussion</p><p>　　3.1. The surface activity</p><p>　　3.1.1. Effect of hydropho

36、bic chain length (nonpolar chain)</p><p>　　Fig. 1 represents the relation between the surface tension and ?log concentration of the synthesized nonionic Schiff base amphiphiles containing similar polyethylen

37、e 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 b

38、e observed that increasing the number of methylene groups along the hydrophobic chains from 10 to 18 units decreases</p><p>　　where, Γmax and NAV are the maximum surface excess and Avogadro’s number, respec

39、tively.</p><p>　　Increasing the maximum surface excess values indicates the increasing of adsorbed molecules at the interface, hence the area available for eachmolecule will decrease. That causes the compact

40、ing of surfactant molecules at the interface to form denser layer. The values of critical micelle concentration, effectiveness, maximum surface excess and minimum surface area of the Schiff base nonionic amphiphiles were

41、 listed in Table 2.</p><p><b>　　3.結(jié)果與討論</b></p><p><b>　　3.1. 表面活性</b></p><p>　　3.1.1. 疏水鏈（非極性鏈）長度的影響</p><p>　　Fig. 1表示表面張力與合成的包含相同分子量聚乙二醇(n=45 E

42、O 單元)的非離子型兩親席夫堿濃度直接的聯(lián)系。很明顯，表面張力具有非離子型表面活性劑的特征，出現(xiàn)了相對較高的表面張力值。隨著從10到18增加疏水鏈上的亞甲基數(shù)，臨界膠束濃度逐漸降低[17]。這種影響在前人的著作中已經(jīng)有了解釋[20,21]，是由于疏水鏈（非極性相）和水相（極性相）存在斥力，這種斥力迫使在空氣/水界面形成分子吸附和在大部分溶液中形成膠束以減小它。含有PEO-2000和油酸做疏水鏈的席夫堿(Table 2) 最低臨界膠束濃度

43、為0.156mM/L，其中提到的上述原因，也是為了在油酸鏈增加不飽和點的排斥程度。緩蝕率的值(π cmc) 隨著增加疏水基的鏈長逐漸降低，它說明表面活性劑分子在界面的累積量增加。最大累積值是臨界膠束濃度下的最低表面張力，最大值為 SB-2000-oleate 的分子數(shù)在44 mN/m時的值。效率值也是最大剩余表面，是兩親分子在空氣/水界面上的聚集程度的一個明確的說明。最大剩余面積值的計算表明，從SB-2000-decanoate到SB-

44、2000-oleate增加趨勢，表示表面張力前臨界膠</p><p>　　式中Γmax表示最大剩余面積，NAV 表示阿伏伽德羅數(shù)。最大剩余面積的增加是表示界面分子吸附的增加，因此每個分子的可用區(qū)域減少。表面活性劑分子間的壓迫力使得在相界面形成致密的膜層。臨界膠束濃度，緩蝕效率，最大剩余表面和最低的非離子型兩親席夫堿最小表面區(qū)域的值分別列于表2。</p><p>　　3.1.2. Effec

45、t of polyethylene oxide content (polar chains)</p><p>　　Fig. 2 represents the effect of ethylene oxide contents on the surface activities of the synthesized nonionic Schiff base amphiphiles at constant hydro

46、phobic chain length (16 methylene groups). It is clear that increasing the number of ethylene oxide units within the nonionic moiety from 9 to 45 and 68 EO units increases the hydrophilic characters of these molecules, w

47、hich increases their critical micelle concentrations and also their surface tension values. Increasing of the CMC values can be r</p><p>　　3.1.2. 聚環(huán)氧乙烷含量的影響（極性鏈）</p><p>　　Fig. 2 表示已合成的非離子型席夫堿的疏水

48、鏈長為常數(shù)（16亞甲基組）時，環(huán)氧乙烷對表面活性的影響。 很明顯，在非離子基團(tuán) 中從9到45和68增加環(huán)氧乙烷的單元數(shù)這些分子的親水性也增強(qiáng)，它增加了它們的臨界膠束濃度和表明張力值。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。最大臨界膠束濃度值的得出是在聚環(huán)氧乙烷鏈最長（n=68）時濃度為1.2 mM/L下。另一方面，非離子型席夫堿兩親分子S

49、B-n- 16的緩蝕效果(πCMC) 隨著非離子基團(tuán)的長度（n）的增加而逐漸變大（這里的n = 9, 45和 68）[22,23]。緩蝕效果(πCMC)和緩蝕效率(pC20)的值說明隨著疏水鏈長度的增加，它們有增多的趨勢。表面張力降低的最大值是 SB-400-palmitate 。最大多余表面值(Γmax)說明席夫堿兩親分子的較低表面濃度有較高的環(huán)氧乙烷含量。SB-400-16 (Table 2)的最大多余表面值最大。相反，最低表面積(

50、A min)值隨著增加非離子鏈長而增大，最大值是SB-3000-16 (T</p><p>　　3.1.3. Thermodynamics of adsorption and micellization</p><p>　　The micellization and adsorption processes of the amphiphile molecules are occurred

51、instantly. But, in common, 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, bo

52、th 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 micellizati</p><p>　　3

53、.1.3.吸附熱力學(xué)和膠束</p><p>　　膠束的形成和兩親分子的吸附過程是瞬間發(fā)生的。但是，一般的一個過程可能比起另一個更為主要。兩個過程中任何一個做主要的都有這一過程的熱力學(xué)變量。研究兩親分子，吸附和熱力學(xué)函數(shù)的計算都基于Rosen 理論[24]和Table 2的表面活性數(shù)據(jù)。膠束自由能變和吸附的負(fù)值表面這兩個過程在25?C 是自發(fā)進(jìn)行的。此外，ΔG mic 隨著增加疏水鏈長度逐漸下降的。但是，ΔGads

54、 的負(fù)值比ΔGmic 稍有增加。ΔGmic 和Gads下降的最大值是SB-2000-oleate分別為?12.04和12.11 kJ/mol 。這表明，這些兩親分子的膠束趨勢比吸附趨勢大。吸附趨勢是指水相和疏水鏈之間的作用，它迫使兩親分子在相界面。這些兩親分子在界面的存在降低了不同階段相互作用。</p><p>　　3.2. Corrosion inhibition efficiency</p>&

55、lt;p>　　3.2.1. Effect of alkyl chain length</p><p>　　Fig. 3 represents the variation of corrosion inhibition efficiency of the synthesized nonionic Schiff bases amphiphiles containing constant ethylene oxi

56、de content (n = 45 EO units). It is clear that the inhibition efficiency increased by increasing the number of repeated methylene groups in the hydrophobic chains. Schiff base polyethylene glycol ABA-2000 showed the maxi

57、mum corrosion inhibition efficiency at 55.28%. Comparison between the corrosion rate of the different hydrophobic chains (Fig. 3</p><p>　　(Amin =110.01A2). Since, the hydrogen evolution and weight loss techn

58、iques were used to assure the accuracy and the reproducibility of the results. Figs. 3 and 4 showed that the inhibition efficiency of the two techniques is highly comparable having very close values. The invariability co

59、nfirms the accuracy of the inhibitors efficiency values. 3.2.緩蝕效果</p><p>　　3.2.1. 烷基鏈長的影響</p><p>　　Fig. 3代表以環(huán)氧乙烷含量(n = 45 EO units)做為常量的非離子席夫堿兩親分子的緩蝕效率變化情況。顯然，緩蝕效率隨著疏水鏈上亞甲基的重復(fù)數(shù)目的增加而增大。聚乙二醇脫落酸- 2

60、000席夫堿的緩蝕效率在55.28%時達(dá)到最大。比較不同疏水鏈的緩蝕速率(Fig. 3)得出如下趨勢：油酸>硬脂酸>棕櫚>癸酸。那種行為能別解釋為兩個因素。第一，這些緩蝕劑在相界面的表面活性。第二，疏水鏈越長彼此相鄰能很容易地重疊。由烷基鏈形成一個緊密的非極性層。這層膜對著侵蝕介質(zhì)，因此能很好的起到隔離作用而是腐蝕過程停止。這些鏈的盤曲（以飽和鏈為例）或/和不飽和點（以油酸衍生物為例）的存在增加了上述的重疊。這種影響明

61、顯出現(xiàn)在硬脂酸和油酸衍生物中(SB-2000-18 and SB-2000-oleate)。增加吸附趨勢（在吸附自由能條件下，ΔGads, Table 2)使緩蝕劑分子移向金屬/腐蝕介質(zhì)的界面，在這里緩蝕劑分子是一個屏障，因此腐蝕過程穩(wěn)步下降[25]。此外，Table 2也說明每個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。這使得分子直觀的在侵蝕介質(zhì)中作為一</p><p>　　3.2

62、.2. Effect of polyethylene oxide chain length</p><p>　　Fig. 5 represents the variation of corrosion inhibition efficiencies of nonionic Schiff base amphiphiles bearing different ethylene oxide contents (mole

63、cular weights = 400, 1000, 2000 and 3000) at constant hydrophobic chain (for palmitate derivative). The corrosion inhibition efficiency was increased by decreasing the PEO content. Higher PEO content increases the hydrop

64、hilicity of the synthesized inhibitors. Hence, inhibitor molecules tend to migrate to the bulk of the aqueous medium , which dec</p><p>　　3.2.2. 聚環(huán)氧乙烷鏈長度的影響</p><p>　　Fig. 5表示不同含量（分子量=400, 1000,

65、2000 和 3000）環(huán)氧乙烷的非離子型席夫堿兩親分子以疏水鏈為常量（棕櫚酸酯衍生物）的緩蝕效率的變化。緩蝕效率隨著據(jù)環(huán)氧乙烷含量的減少而增加。已合成的席夫堿中較高含量的聚環(huán)氧乙烷含量增加了它的親水性。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。這可以從吸附自由能的值(Table 2)看出。因此，它們在金屬表面的積累減少。這也說明了它們作為緩蝕劑的低效率。相反，這些含有低含量PEO的衍生物因為其較高的疏水性而具

66、有較高的表面活性。那引導(dǎo)這些分子在金屬/溶液界面累積。因此，它們的緩蝕效率提高[18]。</p><p>　　3.2.3. Effect of inhibitor doses</p><p>　　Fig. 6 represents the dose effect of the synthesized corrosion inhibitor on their corrosion inhibi

67、tion efficiency for aluminum alloy in acidic medium at 25 ?C. It is clear that at higher inhibitor dose (400 ppm), ηappears in the lowest values. Decreasing the doses to 200 and 100ppm increases the inhibition efficienci

68、es to higher extent, till reaches its maximum value around 100 ppm. Meanwhile, further decrease in the inhibitor concentrations (50, 25 and 10 ppm) turns the efficiencies to lower va</p><p>　　3.2.3.緩蝕劑劑量的影響&

69、lt;/p><p>　　Fig. 6表示已合成的緩蝕劑對鋁合金在25?C時酸性介質(zhì)中緩釋效果的劑量影響。很顯然，緩蝕劑在較高劑量（400 ppm）時η出現(xiàn)了最低值。以200和100ppm降低劑量，緩蝕效率增加更大的程度，直到達(dá)到約100 ppm的最高值。同時，進(jìn)一步減少緩蝕劑濃度（50,25和10ppm），緩蝕效率達(dá)到更低值，但是仍舊比400ppm時高。緩蝕劑可以合理解釋為膠束和這些緩蝕劑（兩親分子）膠束的形成。緩蝕

70、劑在低劑量（10,25和50ppm）時，分子由于其兩親特性吸附在相界面，并參與到金屬表面單層膜的形成，因此而緩蝕效率增加。150ppm被認(rèn)為是一個關(guān)鍵劑量，是由于金屬表面完全被緩蝕劑分子覆蓋，這里出現(xiàn)了最大緩蝕效率。那是因為在此濃度形成了膠束。在降低緩蝕劑濃度時緩蝕效果增加的實現(xiàn)是因為分子機(jī)理而非形成膠束。</p><p>　　3.2.4. Corrosion inhibition mechanism</p

71、><p>　　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

72、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 t

73、he maximum η values at 100 ppm. Then, the efficiency decreased gradually by i</p><p>　　3.2.4. 緩蝕機(jī)理</p><p>　　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。該吸附過程的不同決定參數(shù)幾乎全部取決于這些抑制劑的化學(xué)結(jié)構(gòu)。吸附過程發(fā)生了物理變化或化學(xué)變化. Fig. 6表明緩蝕效率

74、隨著緩蝕劑劑量的增加而增大，最大η值為100 ppm.之后，緩蝕效率隨著緩蝕劑的濃度在200或 400 ppm.時增加而逐漸減小。這表明低濃度時在金屬/溶液界面形成了簡單的緩蝕劑膜。膜的密度在100 ppm以下時隨著劑量的增加而增大。在較高濃度時η的降低表明，沒有形成連續(xù)的膜是由于在較高濃度時形成了膠束[19]。這一結(jié)論能由Fig. 7得出。只形成了一個S型證明在金屬表面形成了單層的緩蝕劑分子膜。筆者認(rèn)為，從研究結(jié)果可以得出結(jié)論，較長的