Zinthu Zomwe Zimayang'anira Kukhazikika kwa Emulsions
Mu ntchito zenizeni, kukhazikika kwa emulsion kumatanthauza kuthekera kwa madontho a gawo logawanika kuti asagwirizane. Pakati pa zoyezera kukhazikika kwa emulsion, kuchuluka kwa kuphatikizika pakati pa madontho ogawanika ndikofunikira kwambiri; zitha kudziwika poyesa momwe kuchuluka kwa madontho pa voliyumu ya unit kumasinthira pakapita nthawi. Pamene madontho mu emulsion amaphatikizana kukhala akuluakulu ndipo pamapeto pake amachititsa kusweka, liwiro la njirayi limadalira kwambiri zinthu zotsatirazi: mawonekedwe enieni a filimu yolumikizana, kugwedezeka kwa electrostatic pakati pa madontho, choletsa cha steric kuchokera ku mafilimu a polymer, kukhuthala kwa gawo lopitilira, kukula kwa madontho ndi kufalikira, chiŵerengero cha voliyumu ya gawo, kutentha, ndi zina zotero.
Mwa izi, mawonekedwe enieni a filimu yolumikizirana, kuyanjana kwa magetsi, ndi zolepheretsa za steric ndizo zofunika kwambiri.
(1) Kapangidwe ka Filimu Yoyang'ana Pamaso
Kugundana pakati pa madontho omwazikana ndiye chinthu chofunikira kwambiri kuti pakhale mgwirizano. Kugwirizana kumapitirira mosalekeza, madontho ang'onoang'ono amachepa kukhala akuluakulu mpaka emulsion itasweka. Pakagundana ndi kusakanikirana, mphamvu ya makina ya filimu yolumikizana ya madontho imakhala ngati chinthu chachikulu chomwe chimatsimikizira kukhazikika kwa emulsion. Kuti filimu yolumikizana ikhale ndi mphamvu yayikulu yamakina, iyenera kukhala filimu yogwirizana—mamolekyu ake opangidwa ndi ma surfactant omangiriridwa pamodzi ndi mphamvu zamphamvu za mbali. Filimuyo iyeneranso kukhala ndi kusinthasintha kwabwino, kotero kuti kuwonongeka komwe kumachitika chifukwa cha kugundana kwa madontho, kumatha kudzikonza yokha.
(2) Kuyanjana kwa Magetsi
Malo otsetsereka m'ma emulsions amatha kukhala ndi mphamvu zina pazifukwa zosiyanasiyana: ionization ya ma ionic surfactants, kuyamwa kwa ma ions enaake pamwamba pa madontho, kukangana pakati pa madontho ndi malo ozungulira, ndi zina zotero. Mu mafuta mu madzi (O/W) emulsions, kuyatsidwa kwa madontho kumachita gawo lofunika kwambiri poletsa kusonkhana, kuphatikizika, ndi kusweka pamapeto pake. Malinga ndi chiphunzitso cha colloid stability, mphamvu za van der Waals zimakoka madontho pamodzi; komabe madontho akayandikira kwambiri kuti pamwamba pawo pakhale zigawo ziwiri, kuponderezedwa kwa electrostatic kumalepheretsa kuyandikirana kwambiri. Mwachionekere, ngati kuponderezedwa kukuposa kukoka, madontho sakhala osavuta kugongana ndi kuphatikizika, ndipo kuponderezedwako kumakhalabe kokhazikika; apo ayi, kuponderezana ndi kusweka kumachitika.
Ponena za madzi mu mafuta (W/O) emulsions, madontho a madzi samakhala ndi mphamvu zambiri, ndipo chifukwa chakuti gawo lopitirira lili ndi dielectric constant yochepa komanso double layer yokhuthala, zotsatira za electrostatic zimangokhudza kukhazikika pang'ono.
(3) Kukhazikika kwa Steric
Pamene ma polima amagwira ntchito ngati ma emulsifier, gawo la interfacial limakhala lolimba kwambiri, ndikupanga chishango cholimba cha lyophilic kuzungulira dontho lililonse - chotchinga cha malo chomwe chimalepheretsa madontho kuti asayandikire ndikukhudzana. Chikhalidwe cha lyophilic cha ma polymer molecules chimakolanso kuchuluka kwa madzi osalekeza mkati mwa gawo loteteza, zomwe zimapangitsa kuti likhale ngati gel. Chifukwa chake, dera la interfacial limasonyeza kukhuthala kwakukulu kwa interfacial ndi viscoelasticity yabwino, zomwe zimathandiza kupewa droplet kugwirizanitsa ndikusunga bata. Ngakhale ngati pali coalescence ina, ma polymer emulsifiers nthawi zambiri amasonkhana pamalo otsika mu mawonekedwe a fibrous kapena crystalline, kukulitsa filimu ya interfacial ndikuletsa coalescence ina.
(4) Kufanana kwa Kugawa kwa Kukula kwa Madontho
Pamene voliyumu yoperekedwa ya gawo logawanika yagawika m'madontho a kukula kosiyanasiyana, dongosolo lokhala ndi madontho akuluakulu limakhala ndi malo ochepa olumikizirana ndipo motero mphamvu yocheperako yolumikizirana imakhala yotsika, zomwe zimapangitsa kuti thermodynamic ikhale yolimba kwambiri. Mu emulsion komwe madontho a kukula kwakukulu ndi ang'onoang'ono azikhala limodzi, madontho ang'onoang'ono nthawi zambiri amachepa pomwe akuluakulu amakula. Ngati kupita patsogolo kumeneku kupitirirabe popanda kuletsa, kusweka kudzachitika pamapeto pake. Chifukwa chake, emulsion yokhala ndi kufalikira kocheperako kwa madontho ofanana imakhala yokhazikika kuposa yomwe kukula kwake kwapakati ndi kofanana koma kukula kwake ndi kwakukulu.
(5) Mphamvu ya Kutentha
Kusintha kwa kutentha kungasinthe mphamvu ya interfacial, makhalidwe ndi kukhuthala kwa interfacial film, kusungunuka kwa emulsifier m'magawo awiriwa, kuthamanga kwa nthunzi ya magawo amadzimadzi, ndi kayendedwe ka kutentha kwa madontho omwazikana. Kusintha konseku kungakhudze kukhazikika kwa emulsion ndipo kungayambitse kusintha kwa gawo kapena kusweka.
Nthawi yotumizira: Novembala-27-2025