表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)活(huo)(huo)(huo)性劑(ji)降低水溶(rong)液的表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)張力(li)是(shi)由于表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)活(huo)(huo)(huo)性劑(ji)分(fen)(fen)子(zi)不(bu)斷取代(dai)表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)的水分(fen)(fen)子(zi)，隨著表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)活(huo)(huo)(huo)性劑(ji)分(fen)(fen)子(zi)不(bu)斷取代(dai)水分(fen)(fen)子(zi)，表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)張力(li)逐漸降低，最終(zhong)在表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)達到飽和，此(ci)時的張力(li)為(wei)平(ping)衡表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)張力(li)，而在表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)活(huo)(huo)(huo)性劑(ji)分(fen)(fen)子(zi)達到飽和前的表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)張力(li)為(wei)動態表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)張力(li)。

用(yong)(yong)最大(da)泡(pao)壓法(fa)測定(ding)了磺(huang)酸鹽型(xing)雙子表(biao)面(mian)(mian)活性劑(ji)1，3-丙二醇雙子琥珀酸二異辛酯(zhi)磺(huang)酸鈉（GSS362）在(zai)不同溫度和濃度下(xia)的動(dong)態(tai)表(biao)面(mian)(mian)張力(li)；采用(yong)(yong)Rosen模型(xing)對動(dong)態(tai)表(biao)面(mian)(mian)張力(li)進(jin)行(xing)了表(biao)征(zheng)，同時(shi)用(yong)(yong)Ward-Tordai方程(cheng)對GSS362的吸附機理(li)進(jin)行(xing)了探討(tao)。實驗結果表(biao)明，GSS362的濃度越(yue)大(da)，動(dong)態(tai)表(biao)面(mian)(mian)張力(li)降低(di)得越(yue)快，且介平(ping)衡值越(yue)接(jie)近平(ping)衡值；溫度升(sheng)高(gao)有利于(yu)GSS362在(zai)新鮮表(biao)面(mian)(mian)的吸附；GSS362在(zai)新鮮表(biao)面(mian)(mian)的吸附前(qian)期為(wei)(wei)擴散控制吸附，吸附后期為(wei)(wei)混合動(dong)力(li)控制吸附。

實驗部分

試劑和儀器

GSS362：經(jing)測定(ding)表面張力(li)曲線無最低點，說明不含(han)高(gao)活(huo)性雜質；實驗用(yong)水均(jun)為二(er)次(ci)去離子水經(jing)亞沸(fei)重(zhong)蒸(zheng)處理(li)。

JK99C型全自動表面張力儀（測量精度0.05 mN/m）：上海中晨數字技(ji)術設備(bei)有限公司；SHA-C型水浴恒溫(wen)振蕩器(qi)（控溫(wen)精度±0.5℃）：金壇市恒豐(feng)儀器(qi)廠；BP100型動態表面張力儀：德國(guo)Kruss公司。

表面性能的測定

系(xi)列濃度表(biao)面活性劑(ji)水溶(rong)液的配制

待測GSS362溶液(ye)的(de)濃度(du)范圍設(she)定(ding)為1×10-6～1×10-2mol/L。首(shou)先配制一定(ding)量(liang)濃度(du)為1×10-2mol/L的(de)GSS362水(shui)溶液(ye)作為母液(ye)備用(yong)，然后移取適(shi)量(liang)母液(ye)逐級稀釋(shi)，得到(dao)一系(xi)列不同(tong)濃度(du)的(de)溶液(ye)，在設(she)定(ding)溫(wen)度(du)的(de)振蕩水(shui)浴鍋中恒溫(wen)30 min。

靜(jing)態表面(mian)張(zhang)力的測定

采用JK99C型表(biao)面(mian)張力(li)儀由低濃度(du)至(zhi)高濃度(du)測定恒溫(wen)后(hou)系列溶(rong)液的(de)(de)表(biao)面(mian)張力(li)（γ），做γ-lgc（c為濃度(du)）曲線。測試(shi)均(jun)在(zai)帶有恒溫(wen)夾套的(de)(de)玻璃杯中進行，外接數(shu)控超級(ji)恒溫(wen)槽(cao)，溫(wen)度(du)控制在(zai)預(yu)設(she)溫(wen)度(du)，溫(wen)度(du)選擇為20，30，40℃。

動態(tai)表(biao)面張力的(de)測定

用BP100型動(dong)(dong)態表(biao)面張力儀由低(di)濃度至(zhi)高濃度測(ce)定恒溫后(hou)系列溶液的(de)動(dong)(dong)態表(biao)面張力。測(ce)試均(jun)在(zai)帶有恒溫夾套的(de)玻璃杯中進行，外接數(shu)控(kong)超級恒溫槽(cao)，溫度控(kong)制在(zai)預設溫度，溫度選擇20，30，40℃。

結果與討論

GSS362水溶液表面張(zhang)力(li)的測定

不同溫度下GSS362水溶液的靜(jing)態表(biao)(biao)面(mian)張(zhang)力見圖1，介(jie)平衡表(biao)(biao)面(mian)張(zhang)力與平衡表(biao)(biao)面(mian)張(zhang)力見表(biao)(biao)1。

圖1不同溫度下GSS362水溶液的靜態(tai)表面張力(li)

表1不同(tong)溫度下的介(jie)平(ping)衡(heng)表面張力與(yu)平(ping)衡(heng)表面張力

圖2不(bu)同溫度下GSS362的(de)動態表面張力

由(you)圖2可知，不同濃(nong)度(du)下，GSS362溶液(ye)動(dong)態(tai)(tai)(tai)表(biao)(biao)面(mian)(mian)(mian)(mian)張(zhang)力下降的(de)趨勢不一樣，濃(nong)度(du)較(jiao)低時（lgc=-4.52），圖1的(de)靜態(tai)(tai)(tai)表(biao)(biao)面(mian)(mian)(mian)(mian)張(zhang)力遠低于溶劑(ji)表(biao)(biao)面(mian)(mian)(mian)(mian)張(zhang)力，而測(ce)得的(de)溶液(ye)動(dong)態(tai)(tai)(tai)表(biao)(biao)面(mian)(mian)(mian)(mian)張(zhang)力等(deng)于溶劑(ji)表(biao)(biao)面(mian)(mian)(mian)(mian)張(zhang)力，因為，在濃(nong)度(du)較(jiao)低時，溶液(ye)相中表(biao)(biao)面(mian)(mian)(mian)(mian)活性劑(ji)分子(zi)濃(nong)度(du)較(jiao)低，分子(zi)擴散至表(biao)(biao)面(mian)(mian)(mian)(mian)的(de)速(su)率較(jiao)慢，因而動(dong)態(tai)(tai)(tai)表(biao)(biao)面(mian)(mian)(mian)(mian)張(zhang)力降低需要較(jiao)長(chang)時間。

在(zai)lgc=-3.00時，可(ke)看出較完整(zheng)的(de)動態(tai)表(biao)(biao)(biao)面(mian)(mian)(mian)張(zhang)力(li)降(jiang)低曲線(xian)，開(kai)始時表(biao)(biao)(biao)面(mian)(mian)(mian)張(zhang)力(li)接(jie)近溶劑的(de)表(biao)(biao)(biao)面(mian)(mian)(mian)張(zhang)力(li)，隨時間的(de)延(yan)長(chang)(chang)表(biao)(biao)(biao)面(mian)(mian)(mian)張(zhang)力(li)先快(kuai)速下降(jiang)，降(jiang)至一(yi)定數值后，降(jiang)幅趨(qu)緩(huan)，在(zai)一(yi)段(duan)時間內(nei)基本(ben)保持不變。因為(wei)氣/液界面(mian)(mian)(mian)新生成時，GSS362尚未在(zai)表(biao)(biao)(biao)面(mian)(mian)(mian)吸(xi)附，界面(mian)(mian)(mian)張(zhang)力(li)為(wei)溶劑的(de)表(biao)(biao)(biao)面(mian)(mian)(mian)張(zhang)力(li)，隨著(zhu)時間的(de)延(yan)長(chang)(chang)，表(biao)(biao)(biao)面(mian)(mian)(mian)活(huo)性劑分(fen)子開(kai)始在(zai)表(biao)(biao)(biao)面(mian)(mian)(mian)吸(xi)附，氣/液界面(mian)(mian)(mian)張(zhang)力(li)降(jiang)低，隨著(zhu)吸(xi)附的(de)進行，表(biao)(biao)(biao)面(mian)(mian)(mian)逐步趨(qu)于飽和，表(biao)(biao)(biao)面(mian)(mian)(mian)活(huo)性劑分(fen)子在(zai)表(biao)(biao)(biao)面(mian)(mian)(mian)吸(xi)附的(de)速率下降(jiang)，因而動態(tai)表(biao)(biao)(biao)面(mian)(mian)(mian)張(zhang)力(li)下降(jiang)速率變慢，趨(qu)于平衡。

而(er)表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)活(huo)(huo)性劑(ji)分(fen)子(zi)在表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)達(da)到(dao)(dao)飽和吸(xi)附(fu)量還需要進一步的(de)(de)吸(xi)附(fu)與定向排列過程(cheng)，因(yin)而(er)觀察(cha)到(dao)(dao)動(dong)態(tai)表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)張(zhang)(zhang)力(li)(li)曲線中(zhong)的(de)(de)張(zhang)(zhang)力(li)(li)值較(jiao)對應(ying)濃(nong)度(du)(du)(du)下的(de)(de)靜態(tai)表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)張(zhang)(zhang)力(li)(li)值高(gao)。而(er)水溶(rong)液(ye)(ye)(ye)中(zhong)GSS362濃(nong)度(du)(du)(du)較(jiao)高(gao)時(shi)(shi)（c＞cmc，cmc為臨界膠束濃(nong)度(du)(du)(du)），表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)活(huo)(huo)性劑(ji)分(fen)子(zi)很快吸(xi)附(fu)到(dao)(dao)表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)，開始測定時(shi)(shi)，新生成的(de)(de)氣(qi)/液(ye)(ye)(ye)界面(mian)(mian)(mian)(mian)(mian)吸(xi)附(fu)較(jiao)多的(de)(de)表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)活(huo)(huo)性劑(ji)分(fen)子(zi)，因(yin)而(er)動(dong)態(tai)表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)張(zhang)(zhang)力(li)(li)低(di)于溶(rong)劑(ji)的(de)(de)表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)張(zhang)(zhang)力(li)(li)，且隨著(zhu)濃(nong)度(du)(du)(du)的(de)(de)增加，初(chu)始動(dong)態(tai)表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)張(zhang)(zhang)力(li)(li)降低(di)。當c＞cmc時(shi)(shi)，為表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)活(huo)(huo)性劑(ji)膠束溶(rong)液(ye)(ye)(ye)，在溶(rong)液(ye)(ye)(ye)表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)上吸(xi)附(fu)的(de)(de)表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)活(huo)(huo)性劑(ji)分(fen)子(zi)達(da)到(dao)(dao)飽和，達(da)到(dao)(dao)平(ping)衡張(zhang)(zhang)力(li)(li)并保持不變。膠束似(si)乎(hu)不具備表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)活(huo)(huo)性，事(shi)實上膠束存在時(shi)(shi)表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)活(huo)(huo)性劑(ji)溶(rong)液(ye)(ye)(ye)表(biao)(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)的(de)(de)吸(xi)附(fu)情況(kuang)比無(wu)膠束時(shi)(shi)復雜得多。

從分子角度(du)看，溶液中(zhong)(zhong)存在(zai)(zai)膠束(shu)形成和分離的(de)過程，從而(er)導致了(le)(le)溶液中(zhong)(zhong)表(biao)(biao)面活性(xing)(xing)劑單體(ti)在(zai)(zai)體(ti)相和表(biao)(biao)面間的(de)傳遞過程，即(ji)在(zai)(zai)表(biao)(biao)面活性(xing)(xing)劑的(de)膠束(shu)溶液中(zhong)(zhong)，單體(ti)與膠束(shu)都參與了(le)(le)動態吸附。