日韩乱码人妻无码中文视频,丰满少妇弄高潮了www,亚洲免费观看视频,国产高清在线a视频大全,97在线视频人妻无码

|
歡迎光(guang)臨(lin)廣州市寶萬化工(gong)有限(xian)公司(si)官網!
全國咨詢熱線:020-29087529
當前位置: 新聞動態 化工產經

表面活性劑的七大作用

時間:2024-12-10 09:40:13 來源:創始人(ren) 點擊:0

1.潤濕作用(yong) 要求(qiu):HLB:7-9

所謂潤(run)濕(shi)(shi)(shi)即(ji)固體(ti)表面吸附的(de)(de)(de)氣體(ti)為液體(ti)所取代的(de)(de)(de)現象, 能增強這(zhe)一(yi)(yi)取代能力的(de)(de)(de)物質稱為潤(run)濕(shi)(shi)(shi)劑。潤(run)濕(shi)(shi)(shi)一(yi)(yi)般分為三類? 接觸潤(run)濕(shi)(shi)(shi)一(yi)(yi)沾濕(shi)(shi)(shi)( 浸(jin)入(ru)潤(run)濕(shi)(shi)(shi)一(yi)(yi)浸(jin)濕(shi)(shi)(shi)( 鋪展(zhan)潤(run)濕(shi)(shi)(shi)一(yi)(yi)鋪展(zhan)。其中鋪展(zhan)是(shi)潤(run)濕(shi)(shi)(shi)的(de)(de)(de)最高標(biao)(biao)準, 常以鋪展(zhan)系數) 作為體(ti)系之間潤(run)濕(shi)(shi)(shi)性(xing)能的(de)(de)(de)指標(biao)(biao)。

此外, 接觸角(jiao)大小也(ye)是(shi)潤濕好壞(huai)的(de)(de)判據 使用表(biao)面(mian)活(huo)性(xing)劑(ji)可以控制液、固之(zhi)間的(de)(de)潤濕程度。農藥(yao)行業中(zhong)在(zai)粒劑(ji)及供噴粉用的(de)(de)粉劑(ji)中(zhong),有(you)的(de)(de)也(ye)含有(you)一定(ding)量的(de)(de)表(biao)面(mian)活(huo)性(xing)劑(ji),其(qi)目的(de)(de)是(shi)為了提(ti)高(gao)藥(yao)劑(ji)在(zai)受藥(yao)表(biao)面(mian)的(de)(de)附著性(xing)和沉積(ji)量,提(ti)高(gao)有(you)效(xiao)(xiao)成分(fen)在(zai)有(you)水(shui)分(fen)條件下的(de)(de)釋放速度和擴展面(mian)積(ji),提(ti)高(gao)防病、治病效(xiao)(xiao)果。

在(zai)化妝品行業中,做(zuo)為乳(ru)化劑(ji)是乳(ru)霜、乳(ru)液(ye)、潔面、卸妝等護膚產品中不可或缺的成分。

2.膠(jiao)束與增溶(rong)作用 要求:C>CMC ( HLB13~18)

表面活性劑分子(zi)締合形成膠束(shu)的最低濃(nong)度。當其濃(nong)度高(gao)于CMC值時,表面活性(xing)劑的排列成球狀、棒狀、束(shu)狀、層狀/板狀等結構。

增溶(rong)體系為熱力學(xue)平衡體系;CMC越(yue)低、締(di)合(he)數越(yue)大(da),增溶(rong)量(liang)(MAC)就越(yue)高;溫度(du)對(dui)增溶(rong)的(de)(de)影響(xiang)(xiang):溫度(du)影響(xiang)(xiang)膠束(shu)的(de)(de)形成,影響(xiang)(xiang)增溶(rong)質的(de)(de)溶(rong)解(jie),影響(xiang)(xiang)表面活性劑的(de)(de)溶(rong)解(jie)度(du) 離子型(xing)表面活性劑的溶解度隨(sui)溫(wen)度增(zeng)加而(er)急(ji)劇(ju)增(zeng)大這(zhe)一溫(wen)度稱為(wei)Krafft點, Krafft點越高(gao),其臨(lin)界膠束濃度(du)越小  。

對于聚氧乙(yi)烯型非離子表面活性(xing)劑,溫度升高到(dao)一(yi)定程度時,溶解度急劇下降并析出,溶液出現混濁,這一(yi)現象稱(cheng)為起曇,此溫度稱(cheng)為曇點(dian)。在聚氧乙烯鏈相同時,碳(tan)(tan)氫鏈越(yue)長,濁點(dian)越(yue)低;在碳(tan)(tan)氫鏈相同時,聚氧乙烯鏈越(yue)長則濁點(dian)越(yue)高。

非極(ji)性有(you)機物如苯在(zai)(zai)水中(zhong)溶(rong)(rong)解度(du)很(hen)小, 加入油(you)酸(suan)鈉等表(biao)面活性劑后, 苯在(zai)(zai)水中(zhong)的溶(rong)(rong)解度(du)大大增(zeng)加, 這稱(cheng)為(wei)增(zeng)溶(rong)(rong)作用(yong)。增(zeng)溶(rong)(rong)作用(yong)與普通的溶(rong)(rong)解概念是(shi)(shi)不(bu)同的, 增(zeng)溶(rong)(rong)的苯不(bu)是(shi)(shi)均勻(yun)分(fen)散在(zai)(zai)水中(zhong), 而是(shi)(shi)分(fen)散在(zai)(zai)油(you)酸(suan)根分(fen)子形成的膠束(shu)中(zhong)。經X射(she)線(xian)衍(yan)射(she)證實, 增(zeng)溶(rong)(rong)后各種膠束(shu)都有(you)不(bu)同程(cheng)度(du)的增(zeng)大, 而整個溶(rong)(rong)液的的依數性(xing)變(bian)化不大。

表面活(huo)性劑(ji)在(zai)水(shui)中隨著濃度(du)增大,表面上聚集的(de)活(huo)性劑(ji)分子形成(cheng)定向排列的(de)緊密單分子層(ceng),多(duo)余的(de)分子在(zai)體相(xiang)內部也(ye)三三兩(liang)兩(liang)的(de)以憎水(shui)基互相(xiang)靠攏,聚集在(zai)一起(qi)形成(cheng)膠束,這開始形成(cheng)膠束的(de)最(zui)低濃度(du)稱為臨(lin)界膠束濃度(du)。

這時溶液性質與理想性質發(fa)生偏離,在表面張力(li)對濃度繪制的(de)曲線上會出現(xian)轉折。繼續(xu)增(zeng)加活性劑(ji)濃度,表面張力(li)不(bu)再(zai)降低,而體(ti)相(xiang)中(zhong)的(de)膠束不(bu)斷(duan)增(zeng)多、增(zeng)大。

表(biao)面(mian)活(huo)性(xing)(xing)(xing)劑(ji)在溶液中分散,當(dang)達到(dao)一定濃(nong)(nong)(nong)度(du)時(shi),表(biao)面(mian)活(huo)性(xing)(xing)(xing)劑(ji)分子(zi)(zi)會(hui)從單體(單個離子(zi)(zi)或分子(zi)(zi))締合成(cheng)(cheng)為(wei)膠(jiao)態(tai)聚集(ji)物(wu),形成(cheng)(cheng)膠(jiao)團。溶液性(xing)(xing)(xing)質(zhi)隨之發生(sheng)突變,此時(shi)的(de)濃(nong)(nong)(nong)度(du),即形成(cheng)(cheng)膠(jiao)團時(shi)的(de)濃(nong)(nong)(nong)度(du),稱為(wei)臨界膠(jiao)團濃(nong)(nong)(nong)度(du)(critical micelle concentration,簡寫為(wei)CMC),表(biao)面(mian)活(huo)性(xing)(xing)(xing)劑(ji)形成(cheng)(cheng)膠(jiao)團的(de)過程稱為(wei)膠(jiao)團化作用。

表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)活性(xing)(xing)(xing)(xing)劑(ji)隨水(shui)溶(rong)(rong)液(ye)(ye)(ye)的(de)(de)(de)(de)(de)濃(nong)(nong)(nong)度(du)(du)變化(hua)(hua)在(zai)(zai)溶(rong)(rong)液(ye)(ye)(ye)中形成(cheng)(cheng)膠團(tuan)(tuan)(tuan)有一(yi)個變化(hua)(hua)的(de)(de)(de)(de)(de)過程,溶(rong)(rong)液(ye)(ye)(ye)中表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)活性(xing)(xing)(xing)(xing)劑(ji)濃(nong)(nong)(nong)度(du)(du)極(ji)低時(shi)即極(ji)稀溶(rong)(rong)液(ye)(ye)(ye)時(shi),空氣和(he)水(shui)幾乎(hu)是(shi)(shi)直接接觸著,水(shui)的(de)(de)(de)(de)(de)表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)張(zhang)力(li)(li)下(xia)降(jiang)不多,接近純水(shui)狀(zhuang)態,水(shui)中只有不多的(de)(de)(de)(de)(de)表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)活性(xing)(xing)(xing)(xing)劑(ji)分(fen)(fen)子,當(dang)稍微增(zeng)加(jia)(jia)(jia)表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)活性(xing)(xing)(xing)(xing)劑(ji)的(de)(de)(de)(de)(de)濃(nong)(nong)(nong)度(du)(du)時(shi),表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)活性(xing)(xing)(xing)(xing)劑(ji)分(fen)(fen)子就(jiu)會很快聚(ju)集(ji)到(dao)(dao)水(shui)面(mian)(mian)(mian)(mian)(mian)(mian),其對水(shui)的(de)(de)(de)(de)(de)遮蓋使水(shui)和(he)空氣的(de)(de)(de)(de)(de)接觸減少,溶(rong)(rong)液(ye)(ye)(ye)的(de)(de)(de)(de)(de)表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)張(zhang)力(li)(li)急劇(ju)下(xia)降(jiang)。而(er)在(zai)(zai)水(shui)中的(de)(de)(de)(de)(de)表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)活性(xing)(xing)(xing)(xing)劑(ji)有一(yi)部(bu)分(fen)(fen)聚(ju)集(ji)在(zai)(zai)一(yi)起,這(zhe)些(xie)表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)活性(xing)(xing)(xing)(xing)劑(ji)的(de)(de)(de)(de)(de)憎(zeng)水(shui)基(ji)互相靠在(zai)(zai)一(yi)起,開(kai)始(shi)形成(cheng)(cheng)小膠團(tuan)(tuan)(tuan),隨著表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)活性(xing)(xing)(xing)(xing)劑(ji)濃(nong)(nong)(nong)度(du)(du)逐漸增(zeng)加(jia)(jia)(jia),當(dang)表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)活性(xing)(xing)(xing)(xing)劑(ji)的(de)(de)(de)(de)(de)溶(rong)(rong)液(ye)(ye)(ye)達(da)到(dao)(dao)飽和(he)吸附時(shi),液(ye)(ye)(ye)面(mian)(mian)(mian)(mian)(mian)(mian)開(kai)始(shi)形成(cheng)(cheng)緊密排列的(de)(de)(de)(de)(de)單分(fen)(fen)子膜。當(dang)溶(rong)(rong)液(ye)(ye)(ye)的(de)(de)(de)(de)(de)濃(nong)(nong)(nong)度(du)(du)達(da)到(dao)(dao)表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)活性(xing)(xing)(xing)(xing)劑(ji)的(de)(de)(de)(de)(de)膠團(tuan)(tuan)(tuan)濃(nong)(nong)(nong)度(du)(du)時(shi),溶(rong)(rong)液(ye)(ye)(ye)的(de)(de)(de)(de)(de)表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)張(zhang)力(li)(li)降(jiang)至最低值(zhi)。如果在(zai)(zai)溶(rong)(rong)液(ye)(ye)(ye)的(de)(de)(de)(de)(de)濃(nong)(nong)(nong)度(du)(du)達(da)到(dao)(dao)臨界(jie)膠團(tuan)(tuan)(tuan)濃(nong)(nong)(nong)度(du)(du)之后(hou),再(zai)繼續增(zeng)加(jia)(jia)(jia)表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)活性(xing)(xing)(xing)(xing)劑(ji),雖然(ran)溶(rong)(rong)液(ye)(ye)(ye)的(de)(de)(de)(de)(de)濃(nong)(nong)(nong)度(du)(du)增(zeng)加(jia)(jia)(jia),但溶(rong)(rong)液(ye)(ye)(ye)的(de)(de)(de)(de)(de)表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)張(zhang)力(li)(li)幾乎(hu)不再(zai)下(xia)降(jiang),此(ci)時(shi)溶(rong)(rong)液(ye)(ye)(ye)中的(de)(de)(de)(de)(de)膠團(tuan)(tuan)(tuan)數(shu)目和(he)聚(ju)集(ji)數(shu)增(zeng)加(jia)(jia)(jia),溶(rong)(rong)液(ye)(ye)(ye)體系(xi)是(shi)(shi)由膠團(tuan)(tuan)(tuan)組成(cheng)(cheng)的(de)(de)(de)(de)(de),納米粉(fen)體合成(cheng)(cheng)所利用(yong)的(de)(de)(de)(de)(de)微反應器就(jiu)是(shi)(shi)此(ci)時(shi)的(de)(de)(de)(de)(de)膠團(tuan)(tuan)(tuan),然(ran)后(hou)體系(xi)漸漸向形成(cheng)(cheng)液(ye)(ye)(ye)晶狀(zhuang)態變化(hua)(hua)。表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)活性(xing)(xing)(xing)(xing)劑(ji)的(de)(de)(de)(de)(de)水(shui)溶(rong)(rong)液(ye)(ye)(ye)在(zai)(zai)濃(nong)(nong)(nong)度(du)(du)達(da)到(dao)(dao)CMC時(shi),表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)活性(xing)(xing)(xing)(xing)劑(ji)會隨其濃(nong)(nong)(nong)度(du)(du)的(de)(de)(de)(de)(de)增(zeng)加(jia)(jia)(jia)形成(cheng)(cheng)膠團(tuan)(tuan)(tuan),這(zhe)一(yi)現(xian)象體現(xian)在(zai)(zai)表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)活性(xing)(xing)(xing)(xing)劑(ji)的(de)(de)(de)(de)(de)表(biao)(biao)(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)(mian)張(zhang)力(li)(li)與濃(nong)(nong)(nong)度(du)(du)曲(qu)線(r-1gc曲(qu)線)上出(chu)現(xian)轉折點(dian),而(er)溶(rong)(rong)液(ye)(ye)(ye)的(de)(de)(de)(de)(de)其他物理化(hua)(hua)學性(xing)(xing)(xing)(xing)質出(chu)現(xian)非理想性(xing)(xing)(xing)(xing)。

對于(yu)離(li)子型表面(mian)活性劑,其形(xing)成的(de)膠團帶(dai)有較高(gao)的(de)電(dian)荷,由于(yu)靜電(dian)引力(li)的(de)作用,在膠團周圍會吸引_些反離(li)子,使(shi)一部分正、負電(dian)荷互相(xiang)抵消。但在膠團形(xing)成高(gao)電(dian)荷后,反離(li)子形(xing)成的(de)離(li)子霧的(de)阻滯力(li)大大增(zeng)加,利用這一點可以調整納米粉體的(de)分散性。由于(yu)這兩(liang)個原因,使(shi)得溶液的(de)當量電(dian)導在CMC之后隨濃度的(de)增(zeng)加迅速(su)下(xia)降,因此(ci),該(gai)點也被(bei)用于(yu)測量表面(mian)活性劑的(de)臨(lin)界膠束(shu)濃度。

離(li)子型(xing)(xing)表面活性劑膠(jiao)(jiao)團(tuan)(tuan)的(de)(de)(de)結(jie)構為球形膠(jiao)(jiao)團(tuan)(tuan),由(you)內核(he)、外殼和擴散雙電層組成(cheng),離(li)子型(xing)(xing)表面活性劑的(de)(de)(de)內核(he)由(you)類似(si)于液(ye)態烴疏水的(de)(de)(de)碳(tan)氫鏈(lian)構成(cheng),其(qi)直(zhi)徑(jing)約l~2.8nm。由(you)于鄰近(jin)極性基-CH2-帶有(you)(you)一定的(de)(de)(de)極性,內核(he)的(de)(de)(de)周圍仍有(you)(you)部(bu)分水分子存在,因此膠(jiao)(jiao)團(tuan)(tuan)內核(he)中還含有(you)(you)較多的(de)(de)(de)滲透水,此時(shi),這(zhe)種-CH2-基團(tuan)(tuan)并不完全是加入(ru)液(ye)態的(de)(de)(de)碳(tan)氫鏈(lian)組成(cheng)的(de)(de)(de)內核(he),而是作為非液(ye)態膠(jiao)(jiao)團(tuan)(tuan)外殼的(de)(de)(de)一部(bu)分。

膠(jiao)(jiao)團(tuan)(tuan)(tuan)的外(wai)(wai)殼也稱為膠(jiao)(jiao)團(tuan)(tuan)(tuan)-水(shui)的“界(jie)面(mian)”或(huo)者(zhe)表(biao)面(mian)相(xiang)。膠(jiao)(jiao)團(tuan)(tuan)(tuan)的外(wai)(wai)殼并非指膠(jiao)(jiao)團(tuan)(tuan)(tuan)與水(shui)的宏(hong)觀界(jie)面(mian),而是指膠(jiao)(jiao)團(tuan)(tuan)(tuan)與單體(ti)水(shui)溶液之間的一(yi)(yi)層(ceng)區(qu)域。對于(yu)離(li)子(zi)(zi)型表(biao)面(mian)活性劑膠(jiao)(jiao)團(tuan)(tuan)(tuan),此外(wai)(wai)殼由(you)膠(jiao)(jiao)團(tuan)(tuan)(tuan)雙電層(ceng)的最內層(ceng)Stern層(ceng)(或(huo)固定吸附層(ceng))組成,其厚約0.2~0.3nm。在(zai)膠(jiao)(jiao)團(tuan)(tuan)(tuan)外(wai)(wai)殼中不僅有表(biao)面(mian)活性劑的離(li)子(zi)(zi)頭及(ji)固定的一(yi)(yi)部分反(fan)離(li)子(zi)(zi),而且由(you)于(yu)離(li)子(zi)(zi)的水(shui)化,膠(jiao)(jiao)團(tuan)(tuan)(tuan)外(wai)(wai)殼還包括水(shui)化層(ceng)。膠(jiao)(jiao)團(tuan)(tuan)(tuan)的外(wai)(wai)殼并非一(yi)(yi)個光(guang)滑的面(mian),而是一(yi)(yi)個“粗糙”不平的面(mian)。這是由(you)于(yu)表(biao)面(mian)活性劑單體(ti)分子(zi)(zi)的熱運動,引起膠(jiao)(jiao)團(tuan)(tuan)(tuan)外(wai)(wai)殼的波動所致。

在非水(shui)(油(you)性(xing))介質中,油(you)性(xing)分子占(zhan)大多數(shu),表(biao)面(mian)活(huo)性(xing)劑(ji)親(qin)水(shui)基團在膠(jiao)(jiao)團內(nei)部構(gou)成(cheng)(cheng)極性(xing)基內(nei)核,而由疏水(shui)的(de)(de)碳氫鏈構(gou)成(cheng)(cheng)膠(jiao)(jiao)團的(de)(de)外殼,所形成(cheng)(cheng)的(de)(de)膠(jiao)(jiao)團與(yu)(yu)常規膠(jiao)(jiao)團相反,因此稱之(zhi)為反膠(jiao)(jiao)團,與(yu)(yu)之(zhi)對應,在水(shui)中的(de)(de)膠(jiao)(jiao)束叫正膠(jiao)(jiao)團。圖4為表(biao)面(mian)活(huo)性(xing)劑(ji)在非水(shui)溶液(ye)中形成(cheng)(cheng)的(de)(de)反膠(jiao)(jiao)團模型。近年來反膠(jiao)(jiao)團被廣泛用于納(na)米藥物載體的(de)(de)合成(cheng)(cheng)和制備中,例如,親(qin)水(shui)性(xing)藥物的(de)(de)包(bao)覆。

3.乳化(hua)作用(yong)

表(biao)面(mian)(mian)活(huo)性(xing)劑分子中(zhong)親(qin)(qin)水(shui)和親(qin)(qin)油(you)基團對油(you)或水(shui)的(de)綜(zong)合親(qin)(qin)合力。根據經驗,將表(biao)面(mian)(mian)活(huo)性(xing)劑的(de)HLB值(zhi)范圍(wei)限定(ding)在0-40,非離子型的(de)HLB值(zhi)在0-20。

混合加和性:HLB=(HLBa Wa+HLBb /Wb) / (Wa+Wb)    理(li)論計算:HLB=∑(親水基(ji)團(tuan)HLB值)+∑(親油基(ji)團(tuan)HLB)-7    HLB:3-8 W /O型乳化劑:Tween;一價(jia)皂HLB:8-16 O/W型乳化劑:Span;二價(jia)皂

一(yi)種或幾種液(ye)(ye)(ye)體以(yi)大于10-7m直徑的(de)液(ye)(ye)(ye)珠分(fen)(fen)(fen)散(san)(san)在另(ling)一(yi)不(bu)相(xiang)混(hun)溶的(de)液(ye)(ye)(ye)體之中(zhong)形(xing)成(cheng)(cheng)的(de)粗(cu)分(fen)(fen)(fen)散(san)(san)體系稱為(wei)乳(ru)(ru)(ru)(ru)狀(zhuang)(zhuang)(zhuang)液(ye)(ye)(ye)。要(yao)(yao)使它穩定存在必須加乳(ru)(ru)(ru)(ru)化劑。根(gen)據乳(ru)(ru)(ru)(ru)化劑結構的(de)不(bu)同可以(yi)形(xing)成(cheng)(cheng)以(yi)水為(wei)連續相(xiang)的(de)水包油乳(ru)(ru)(ru)(ru)狀(zhuang)(zhuang)(zhuang)液(ye)(ye)(ye)(O/W),或以(yi)油為(wei)連續相(xiang)的(de)油包水乳(ru)(ru)(ru)(ru)狀(zhuang)(zhuang)(zhuang)液(ye)(ye)(ye)(W/O)。有(you)時為(wei)了破(po)壞乳(ru)(ru)(ru)(ru)狀(zhuang)(zhuang)(zhuang)液(ye)(ye)(ye)需加入(ru)另(ling)一(yi)種表面(mian)活性劑,稱為(wei)破(po)乳(ru)(ru)(ru)(ru)劑,將(jiang)乳(ru)(ru)(ru)(ru)狀(zhuang)(zhuang)(zhuang)液(ye)(ye)(ye)中(zhong)的(de)分(fen)(fen)(fen)散(san)(san)相(xiang)和分(fen)(fen)(fen)散(san)(san)介質分(fen)(fen)(fen)開(kai)。例如原油中(zhong)需要(yao)(yao)加入(ru)破(po)乳(ru)(ru)(ru)(ru)劑將(jiang)油與水分(fen)(fen)(fen)開(kai)。

4.起(qi)泡(pao)和消(xiao)泡(pao)作用

表面(mian)活(huo)性(xing)劑(ji)在(zai)(zai)醫藥(yao)(yao)行(xing)業也(ye)有廣(guang)泛應用(yong)(yong)(yong)。在(zai)(zai)藥(yao)(yao)劑(ji)中,一些揮發油(you)脂(zhi)溶(rong)(rong)性(xing)纖維素、甾體激素等(deng)許多難溶(rong)(rong)性(xing)藥(yao)(yao)物(wu)利用(yong)(yong)(yong)表面(mian)活(huo)性(xing)劑(ji)的(de)增溶(rong)(rong)作用(yong)(yong)(yong)可(ke)形成(cheng)透(tou)明溶(rong)(rong)液及增加(jia)濃度(du);藥(yao)(yao)劑(ji)制(zhi)備過程(cheng)中,它是不(bu)可(ke)缺(que)少的(de)乳化劑(ji)、潤濕劑(ji)、助懸劑(ji)、起(qi)泡(pao)劑(ji)和消泡(pao)劑(ji)等(deng)。“泡(pao)”就是由液體薄(bo)膜(mo)包圍著(zhu)氣體。有的(de)表面(mian)活(huo)性(xing)劑(ji)和水可(ke)以形成(cheng)一定強度(du)的(de)薄(bo)膜(mo),包圍著(zhu)空氣而形成(cheng)泡(pao)沫(mo)(mo),用(yong)(yong)(yong)于(yu)浮游選礦、泡(pao)沫(mo)(mo)滅火和洗滌去(qu)污等(deng),這種(zhong)活(huo)性(xing)劑(ji)稱為起(qi)泡(pao)劑(ji)。也(ye)有時要使(shi)用(yong)(yong)(yong)消泡(pao)劑(ji),在(zai)(zai)制(zhi)糖、制(zhi)中藥(yao)(yao)過程(cheng)中泡(pao)沫(mo)(mo)太多,要加(jia)入適當的(de)表面(mian)活(huo)性(xing)劑(ji)降低薄(bo)膜(mo)強度(du),消除氣泡(pao),防止事故。

5.助(zhu)懸作用

在(zai)農藥行業,可(ke)濕(shi)性(xing)(xing)粉劑、乳(ru)油(you)及濃乳(ru)劑都需要(yao)有(you)(you)(you)一定量的(de)表面活(huo)性(xing)(xing)劑,如可(ke)濕(shi)性(xing)(xing)粉劑中原藥多為有(you)(you)(you)機化(hua)合物,具有(you)(you)(you)憎(zeng)水性(xing)(xing),只有(you)(you)(you)在(zai)表面活(huo)性(xing)(xing)劑存在(zai)的(de)條件下,降低水的(de)表面張力(li),藥粒才(cai)有(you)(you)(you)可(ke)能被水所(suo)潤濕(shi),形成(cheng)水懸液(ye)。

表面活性(xing)劑用于礦石(shi)的(de)浮選,就(jiu)是運用助浮作(zuo)用。攪拌并(bing)從(cong)池(chi)底(di)鼓(gu)氣,帶有(you)(you)有(you)(you)效礦粉的(de)氣泡聚集(ji)表面,收集(ji)并(bing)滅泡濃(nong)縮,從(cong)而達到了富集(ji)的(de)目的(de)。不含礦石(shi)的(de)泥(ni)砂、巖石(shi)留在池(chi)底(di),定時(shi)(shi)清除。當礦砂表面有(you)(you)5%被捕集(ji)劑覆蓋(gai)時(shi)(shi),就(jiu)使表面產(chan)生憎水性(xing),它會附在氣泡上一起升到液(ye)面,便于收集(ji)。選擇合適的(de)捕集(ji)劑,使它的(de)親水基團只吸在礦砂的(de)表面,憎水基朝向水。

6.消毒、殺菌

在醫藥行業(ye)中可(ke)作為殺菌劑和消(xiao)毒(du)(du)劑使(shi)用,其殺菌和消(xiao)毒(du)(du)作用歸結于(yu)它(ta)們與細菌生物膜蛋白(bai)質(zhi)的強烈相互作用使(shi)之變性或(huo)失去功能(neng),這些(xie)消(xiao)毒(du)(du)劑在水中都有比較大的溶(rong)解度(du),根據(ju)使(shi)用濃度(du),可(ke)用于(yu)手術(shu)前(qian)皮(pi)膚消(xiao)毒(du)(du)、傷口或(huo)粘(zhan)膜消(xiao)毒(du)(du)、器械(xie)消(xiao)毒(du)(du)和環境消(xiao)毒(du)(du);

7.去垢、洗滌作用

去(qu)除油(you)脂污(wu)(wu)垢(gou)(gou)(gou)是一個比較(jiao)復(fu)雜的(de)過程,它與(yu)上面(mian)(mian)提到的(de)潤濕(shi)、起泡等(deng)(deng)作用均有(you)關(guan)。洗(xi)(xi)滌劑(ji)中(zhong)通常要加入多種輔助(zhu)成(cheng)分,增加對(dui)(dui)被清洗(xi)(xi)物(wu)體的(de)潤濕(shi)作用,又要有(you)起泡、增白、占領清潔表(biao)面(mian)(mian)不被再次污(wu)(wu)染等(deng)(deng)功能。其(qi)中(zhong)作為主要成(cheng)分的(de)表(biao)面(mian)(mian)活(huo)性(xing)(xing)劑(ji)的(de)去(qu)污(wu)(wu)過程是:水的(de)表(biao)面(mian)(mian)張力大,對(dui)(dui)油(you)污(wu)(wu)潤濕(shi)性(xing)(xing)能差,不容易把油(you)污(wu)(wu)洗(xi)(xi)掉。加入表(biao)面(mian)(mian)活(huo)性(xing)(xing)劑(ji)后,憎水基(ji)團朝向織物(wu)表(biao)面(mian)(mian)和吸附在污(wu)(wu)垢(gou)(gou)(gou)上,使(shi)污(wu)(wu)垢(gou)(gou)(gou)逐步(bu)脫離表(biao)面(mian)(mian)。污(wu)(wu)垢(gou)(gou)(gou)懸在水中(zhong)或隨泡沫浮到水面(mian)(mian)后被去(qu)除,潔凈(jing)表(biao)面(mian)(mian)被表(biao)面(mian)(mian)活(huo)性(xing)(xing)劑(ji)分子占領。

最后(hou)要說明的(de)是,表面活(huo)性(xing)劑(ji)(ji)起(qi)作(zuo)用,并(bing)不單單是因為某一方(fang)面的(de)作(zuo)用,很多(duo)情況下是多(duo)種因素共同作(zuo)用。如在造紙工(gong)業中可以用作(zuo)蒸(zheng)煮劑(ji)(ji)、廢紙脫墨劑(ji)(ji)、施(shi)膠(jiao)劑(ji)(ji)、樹脂(zhi)障(zhang)礙控制劑(ji)(ji)、消(xiao)泡劑(ji)(ji)、柔(rou)軟(ruan)劑(ji)(ji)、抗靜電劑(ji)(ji)、阻垢劑(ji)(ji)、軟(ruan)化劑(ji)(ji)、除油劑(ji)(ji)、殺(sha)菌滅藻劑(ji)(ji)、緩蝕劑(ji)(ji)等。


轉載自:化工好料到

來源:表面活性劑發展中心

在線客服
聯系方式

熱線電話

020-29087529

上班時間

周一到周五

二維碼