表面活性劑(surfactant)，是(shi)指具(ju)有固定的(de)親水(shui)親油基(ji)團(tuan)(tuan)，在溶液的(de)表(biao)(biao)面(mian)能定向(xiang)排列，并能使表(biao)(biao)面(mian)張力(li)顯著(zhu)下降的(de)物質。表(biao)(biao)面(mian)活(huo)性(xing)(xing)(xing)劑(ji)(ji)的(de)分子(zi)結構(gou)具(ju)有兩親性(xing)(xing)(xing)：一(yi)端為(wei)親水(shui)基(ji)團(tuan)(tuan)，另(ling)一(yi)端為(wei)憎水(shui)基(ji)團(tuan)(tuan)；親水(shui)基(ji)團(tuan)(tuan)常(chang)為(wei)極性(xing)(xing)(xing)的(de)基(ji)團(tuan)(tuan)，如羧(suo)酸、磺(huang)酸、硫酸、氨基(ji)或胺(an)(an)基(ji)及其鹽，也(ye)可是(shi)羥基(ji)、酰胺(an)(an)基(ji)、醚鍵等(deng)(deng)；而憎水(shui)基(ji)團(tuan)(tuan)常(chang)為(wei)非極性(xing)(xing)(xing)烴鏈，如8個碳原子(zi)以上烴鏈。表(biao)(biao)面(mian)活(huo)性(xing)(xing)(xing)劑(ji)(ji)分為(wei)離(li)(li)子(zi)型表(biao)(biao)面(mian)活(huo)性(xing)(xing)(xing)劑(ji)(ji)和非離(li)(li)子(zi)型表(biao)(biao)面(mian)活(huo)性(xing)(xing)(xing)劑(ji)(ji)等(deng)(deng)。

    增(zeng)(zeng)(zeng)溶(rong)(rong)(rong)(rong)：要(yao)求：C>CMC(HLB13~18)臨界膠(jiao)(jiao)束(shu)濃度(du)(du)(du)(CMC)：表(biao)(biao)面活(huo)性劑(ji)分子締(di)合(he)(he)形成膠(jiao)(jiao)束(shu)的最低濃度(du)(du)(du)。當(dang)其濃度(du)(du)(du)高于CMC值時(shi)(shi)，表(biao)(biao)面活(huo)性劑(ji)的排列成球狀(zhuang)、棒(bang)狀(zhuang)、束(shu)狀(zhuang)、層狀(zhuang)/板狀(zhuang)等(deng)結構。增(zeng)(zeng)(zeng)溶(rong)(rong)(rong)(rong)體系為熱力學(xue)平衡(heng)體系；CMC越(yue)(yue)(yue)(yue)低、締(di)合(he)(he)數(shu)越(yue)(yue)(yue)(yue)大(da)，增(zeng)(zeng)(zeng)溶(rong)(rong)(rong)(rong)量(liang)(MAC)就(jiu)越(yue)(yue)(yue)(yue)高；溫(wen)度(du)(du)(du)對增(zeng)(zeng)(zeng)溶(rong)(rong)(rong)(rong)的影響(xiang)(xiang)：溫(wen)度(du)(du)(du)影響(xiang)(xiang)膠(jiao)(jiao)束(shu)的形成，影響(xiang)(xiang)增(zeng)(zeng)(zeng)溶(rong)(rong)(rong)(rong)質的溶(rong)(rong)(rong)(rong)解(jie)，影響(xiang)(xiang)表(biao)(biao)面活(huo)性劑(ji)的溶(rong)(rong)(rong)(rong)解(jie)度(du)(du)(du)Krafft點(dian)：離(li)子型表(biao)(biao)面活(huo)性劑(ji)的溶(rong)(rong)(rong)(rong)解(jie)度(du)(du)(du)隨溫(wen)度(du)(du)(du)增(zeng)(zeng)(zeng)加而急劇增(zeng)(zeng)(zeng)大(da)這(zhe)一(yi)溫(wen)度(du)(du)(du)稱為Krafft點(dian)，Krafft點(dian)越(yue)(yue)(yue)(yue)高，其臨界膠(jiao)(jiao)束(shu)濃度(du)(du)(du)越(yue)(yue)(yue)(yue)小曇(tan)點(dian)：對于聚氧(yang)乙烯(xi)型非離(li)子表(biao)(biao)面活(huo)性劑(ji)，溫(wen)度(du)(du)(du)升高到一(yi)定程度(du)(du)(du)時(shi)(shi)，溶(rong)(rong)(rong)(rong)解(jie)度(du)(du)(du)急劇下(xia)降(jiang)并析出，溶(rong)(rong)(rong)(rong)液出現(xian)混濁(zhuo)(zhuo)，這(zhe)一(yi)現(xian)象稱為起(qi)曇(tan)，此溫(wen)度(du)(du)(du)稱為曇(tan)點(dian)。在聚氧(yang)乙烯(xi)鏈(lian)(lian)相同時(shi)(shi)，碳氫(qing)(qing)鏈(lian)(lian)越(yue)(yue)(yue)(yue)長(chang)，濁(zhuo)(zhuo)點(dian)越(yue)(yue)(yue)(yue)低；在碳氫(qing)(qing)鏈(lian)(lian)相同時(shi)(shi)，聚氧(yang)乙烯(xi)鏈(lian)(lian)越(yue)(yue)(yue)(yue)長(chang)則(ze)濁(zhuo)(zhuo)點(dian)越(yue)(yue)(yue)(yue)高。

    乳化(hua)作用：親水(shui)(shui)親油平衡值(zhi)(zhi)(HLB)：表(biao)面(mian)活性(xing)劑分(fen)子中親水(shui)(shui)和(he)親油基團(tuan)對油或水(shui)(shui)的綜(zong)合親合力。根據經驗，將表(biao)面(mian)活性(xing)劑的HLB值(zhi)(zhi)范圍限定在(zai)(zai)0-40，非離子型的HLB值(zhi)(zhi)在(zai)(zai)0-20。混(hun)合加和(he)性(xing)：HLB=(HLBaWa+HLBb/Wb)/(Wa+Wb)理論計算：HLB=∑(親水(shui)(shui)基團(tuan)HLB值(zhi)(zhi))+∑(親油基團(tuan)HLB)-7HLB：3-8W/O型乳化(hua)劑：Tween；一價皂(zao)HLB：8-16O/W型乳化(hua)劑：Span；二價皂(zao)。

    潤濕作用(yong)：要求：HLB：7-9。使(shi)用(yong)表面活性(xing)劑(ji)可(ke)以(yi)控(kong)制液(ye)、固之(zhi)間的潤濕程度(du)。農藥(yao)(yao)行業(ye)中(zhong)在粒劑(ji)及供噴(pen)粉用(yong)的粉劑(ji)中(zhong)，有(you)的也含有(you)一定量(liang)的表面活性(xing)劑(ji)，其目的是(shi)為了提(ti)高藥(yao)(yao)劑(ji)在受藥(yao)(yao)表面的附著性(xing)和沉積(ji)量(liang)，提(ti)高有(you)效(xiao)成分(fen)在有(you)水分(fen)條件下的釋放速度(du)和擴展面積(ji)，提(ti)高防病(bing)、治病(bing)效(xiao)果。在化(hua)妝(zhuang)品行業(ye)中(zhong)，做為乳(ru)化(hua)劑(ji)是(shi)乳(ru)霜、乳(ru)液(ye)、潔面、卸(xie)妝(zhuang)等護膚產品中(zhong)不可(ke)或缺的成分(fen)。

    助懸作用：在(zai)農藥行業，可(ke)濕(shi)性(xing)粉劑、乳(ru)油及濃乳(ru)劑都需要有一定量的表(biao)面(mian)(mian)活性(xing)劑，如可(ke)濕(shi)性(xing)粉劑中原藥多(duo)為有機化合物，具有憎(zeng)水(shui)(shui)性(xing)，只有在(zai)表(biao)面(mian)(mian)活性(xing)劑存在(zai)的條件下，降低水(shui)(shui)的表(biao)面(mian)(mian)張力，藥粒才(cai)有可(ke)能被水(shui)(shui)所潤濕(shi)，形成(cheng)水(shui)(shui)懸液；

    起泡(pao)和消泡(pao)作用：表面活(huo)性劑在(zai)醫(yi)藥行業也有廣泛應(ying)用。在(zai)藥劑中(zhong)，一些揮發油(you)脂(zhi)溶性纖維素、甾體激素等許多難溶性藥物利用表面活(huo)性劑的增溶作用可形(xing)成透(tou)明溶液及增加(jia)濃度；藥劑制(zhi)備過程中(zhong)，它(ta)是不可缺少的乳化(hua)劑、潤濕(shi)劑、助懸劑、起泡(pao)劑和消泡(pao)劑等。

    消(xiao)毒(du)(du)(du)、殺菌：在(zai)醫藥(yao)行業(ye)中可(ke)作(zuo)為殺菌劑(ji)和消(xiao)毒(du)(du)(du)劑(ji)使用(yong)，其(qi)殺菌和消(xiao)毒(du)(du)(du)作(zuo)用(yong)歸結(jie)于(yu)它(ta)們與(yu)細菌生物(wu)膜蛋白質(zhi)的強烈相互作(zuo)用(yong)使之變性或失去功能，這(zhe)些消(xiao)毒(du)(du)(du)劑(ji)在(zai)水(shui)中都(dou)有比較大的溶解度，根據使用(yong)濃度，可(ke)用(yong)于(yu)手術前皮(pi)膚消(xiao)毒(du)(du)(du)、傷(shang)口或粘膜消(xiao)毒(du)(du)(du)、器械消(xiao)毒(du)(du)(du)和環(huan)境消(xiao)毒(du)(du)(du)；

    去垢(gou)、洗滌作用：去除油脂(zhi)污(wu)垢(gou)是一個(ge)比較復(fu)雜的過程，它(ta)與上面提(ti)到的潤濕、起泡等作用均有關(guan)。

資訊來源： 供應(ying)商  揚州晨(chen)化新(xin)材料(liao)股(gu)份有(you)限公司