Umphumela we-pH ekwakhiweni kwesilinganiso
Ezimbonini zemithi, izimonyo, kanye nezempilo, impumelelo yomkhiqizo ayinqunywa nje kuphela yizithako ezisebenzayo ezisetshenziswayo, kodwa futhi nangezimo zemvelo ngaphakathi kokwakheka. Enye yemingcele ebaluleke kakhulu yi-pH, isilinganiso se-acidity noma i-alkalinity yesistimu. I-pH ingathinta ukuzinza kwezithako ezisebenzayo, ukusebenza kahle kwezilondolozi, induduzo yokusetshenziswa, ngisho nokuphepha komkhiqizo. Ngakho-ke, ukuqonda umthelela we-pH ekwakhiweni komkhiqizo kuyisisekelo esibalulekile sokuthuthukisa imikhiqizo ephephile, ezinzile, nephumelelayo.
Umqondo Oyisisekelo we-pH Nokufaneleka Kwayo Ekulungiseleleni
I-pH iyisilinganiso se-logarithmic esibonisa ukuhlushwa kwama-ion e-hydrogen (H⁺) esixazululweni. Isikali se-pH ngokuvamile sisukela ku-0–14: i-pH < 7 ine-acidic, i-pH = 7 ayithathi hlangothi, kanti i-pH > 7 iyisisekelo. Emongweni wezinhlobo zomthamo, i-pH ingaphezu nje kwenombolo; imelela izimo zamakhemikhali ezingathinta ukuncibilika, i-ionization, i-reactivity, kanye nokuzinza kwezingxenye ezahlukene zefomula.
Uhlobo ngalunye lokulungiselela—isibonelo, isiraphu, i-suspension, ukhilimu, ijeli, amaconsi amehlo, isisombululo esijovwayo, noma i-shampoo—lunezinga le-pH elihlukile. Lolu hlu lukhethwa ngokusekelwe ezintweni eziningana ezibalulekile: uhlobo lwesithako esisebenzayo, izici zezinto ezisizayo, amathuba okucasuka ezicutshini zomzimba, kanye nesidingo sokuqina ngesikhathi sokugcina.
i-pH kanye nokuzinza kwezithako ezisebenzayo
Enye yethonya elibaluleke kakhulu le-pH ekwakhiweni kwayo iwukuzinza kwamakhemikhali kwezithako ezisebenzayo. Izithako eziningi zemithi noma izithako ezisebenzayo zezimonyo zisengozini yokuwohloka ezimweni ezithile ze-pH. Isibonelo, ezinye izithako ziqhekeka kalula ngamanzi (ziqhekeka ngamanzi) ezimweni ezine-acidic kakhulu noma ezine-alkaline kakhulu. Ukusabela okuthile kwe-oxidation, i-isomerization, kanye nokuqhekeka kwezibopho nakho kungasheshiswa noma kwehliswe kuye nge-pH.
Isibonelo, i-vitamin C (i-ascorbic acid) ivame ukuzinza kakhulu ezimweni ze-acidic. Ngakho-ke, imikhiqizo ye-vitamin C serum ivame ukwakheka nge-pH ephansi ukuze kulondolozwe amandla futhi kuncishiswe i-oxidation. Ngokuphambene nalokho, izithako ezithile zingaba ezingazinzile nge-pH ephansi kakhulu futhi zidinge i-pH eseduze ne-neutral ukuze kuvinjelwe ukuwohloka.
Embonini yezemithi, i-pH nayo ithinta ukuzinza komzimba, isibonelo ekumisweni noma ekumisweni. Izinguquko ku-pH zingashintsha ukushaja kobuso bezinhlayiya, okubangela ukuba zihlangane ndawonye (ukugoqana) noma ziqine (ukungagoqina), ekugcineni kuthinte ukufana kokulungiselela kanye nomthamo wesiguli.
i-pH, i-Ionization, kanye nokuncibilika
I-pH inquma kakhulu izinga lokufakwa kwe-ion kwesithako esisebenzayo, ikakhulukazi kuma-compounds angama-acid abuthakathaka noma izisekelo ezibuthakathaka. Leli zinga lokufakwa kwe-ion lizothinta ukuncibilika emanzini. Ama-compounds amaningi ancibilika kakhulu esimweni sawo se-ionic, ngakho-ke i-pH ingalungiswa ukuze kwandiswe ukuncibilika futhi kuvinjelwe imvula.
Lo mqondo uvame ukusetshenziswa ekwakhiweni kwesisombululo somlomo noma esijovwayo. Uma umuthi ungancibiliki kahle, ukulungiswa kwe-pH kungasiza ekugcineni ukuncibilika. Kodwa-ke, izinguquko ze-pH ukuze kwandiswe ukuncibilika kumele zicabangele ezinye izingozi ezifana nokucasuka, ukungahambelani nezinto ezisizayo, noma ukwehla kokuqina.
Ngaphezu kwalokho, i-pH iphinde ithinte ukungena kwamanzi ngokusebenzisa ama-membrane ezinto eziphilayo. Ngokuvamile, amafomu angewona ama-ionic angena kalula kuma-membrane e-lipid, kuyilapho amafomu e-ionic eba nesikhathi esinzima. Lokhu kubalulekile ekwakhiweni kwangaphandle kanye nakwe-transdermal, njengoba i-pH ingathinta ukuthi isithako esisebenzayo singangena esikhumbeni kangakanani.
Umphumela we-pH ezinhlelweni zokuvikela kanye nezokulwa namagciwane
Amalungiselelo asekelwe emanzini asengozini yokungcoliswa amagciwane, adinga izithasiselo. Ukusebenza kahle kwezithasiselo ezithile kuncike kakhulu ku-pH. Ezinye izithasiselo zisebenza kahle kakhulu emazingeni e-pH ane-acidic ngoba isimo sazo esingeyona i-ionic singena kalula emangqamuzaneni amagciwane futhi siphazamise i-metabolism.
Isibonelo, i-benzoic acid kanye ne-sorbic acid zisebenza kahle kakhulu uma i-pH iphansi. Uma i-pH iphezulu kakhulu, lezi zigcina-mpilo ezimbili zizoba sesimweni se-ionic, ngaleyo ndlela zinciphise umsebenzi wazo wokulwa namagciwane. Lokhu kusho ukuthi i-pH engafanele ingabangela ukuthi izigcina-mpilo "zingasebenzi kahle," okwandisa ingozi yokukhula kwamagciwane, ukwehla kwekhwalithi, iphunga elibi, ngisho nengozi yokutheleleka kubasebenzisi.
Ngakolunye uhlangothi, ukusetshenziswa kwezilondolozi kumele kusacabangele ukuphepha kanye nokucasuka okungenzeka. Amazinga aphezulu e-pH angalimaza kakhulu ukubekezelelana kwesikhumba noma ulwelwesi lwamafinyila.
i-pH kanye nenduduzo kanye nokuphepha kokusetshenziswa
Imikhiqizo esetshenziswa emzimbeni kufanele icabangele i-pH yomzimba yendawo okuqondiswe kuyo. Isikhumba somuntu ngokuvamile sine-acid mantle ene-pH engaba ngu-4,5–5,5. Imikhiqizo esetshenziswa ngaphandle njengensipho, okhilimu, noma ama-toner ane-pH ephezulu kakhulu ingaphazamisa isithiyo semvelo sesikhumba, ibangele ukoma, ukucasuka, noma ukwenza izimo ezithile zibe zimbi kakhulu njenge-dermatitis kanye ne-acne.
Kumalungiselelo amehlo (amaconsi eso), i-pH ekahle ivame ukusondela ku-pH yezinyembezi (cishe u-7,0–7,4) ukuze kugwenywe ukucasuka. Kodwa-ke, i-pH ngezinye izikhathi ilungiswa ukuqinisekisa ukuzinza kwesithako esisebenzayo, bese isekelwa uhlelo lwe-buffer ukuze kusetshenziswe kahle. Kumalungiselelo e-parenteral (imijovo), i-pH kumele futhi ilawulwe ngokuqinile ukuze kuvinjelwe ubuhlungu ngesikhathi somjovo futhi kuvinjelwe ukulimala kwezicubu.
Ngakho-ke, ukwakheka okuhle kuvame ukuba yisivumelwane phakathi kokuqina nokubekezeleleka. Imikhiqizo ingase yakhiwe nge-pH ethile ukuze kulondolozwe ukuqina kwesithako esisebenzayo, kodwa kusazanywa ukuqinisekisa ukuthi ingaphakathi kobubanzi obungaba yingozi kumsebenzisi.
Indima Yama-Buffers Ekulondolozeni i-pH Ezinzile
Izinhlelo ze-buffer zisetshenziselwa ukugcina i-pH yomuthi ukuze ungashintshi kalula ngenxa yokuchayeka emoyeni, ekukhanyeni, ekushiseni, noma ekungcoleni okuncane ngesikhathi sokusetshenziswa. Izinguquko ku-pH ngesikhathi sokugcina zingabangela imvula, izinguquko ze-viscosity, izinguquko zombala, ngisho nokwehla kwamazinga ezithako ezisebenzayo.
Ukukhetha i-buffer kufanele kucabangele ukuhambisana nezinye izithako ezisebenzayo kanye nezinto ezisizayo. I-buffer enamandla kakhulu ingabangela ukungakhululeki ezicutshini, njengamehlo noma impumulo. Ngakho-ke, kufanele kucatshangelwe ngokucophelela uhlobo kanye namandla e-buffer.
i-pH kanye nokuzinza kwama-Emulsion nama-Gel
Kuma-emulsion (isb., okhilimu noma ama-lotion), i-pH ingathinta ukuzinza kwesistimu ye-surfactant esetshenziswayo. Amanye ama-emulsifier asebenza kahle kakhulu ku-pH ethile; izinguquko ku-pH zingabangela ukuthi i-emulsion iphuke (ukuhlukaniswa kwesigaba). Kuma-gel, i-pH ithinta ukwakheka kwenethiwekhi ye-polymer. Isibonelo, amanye ama-gelling agents, njenge-carbomer, adinga ukuncishiswa (isb., ngesisekelo) ukuze afinyelele i-viscosity ephezulu. Uma i-pH iphansi kakhulu, i-gel ingaba manzi kakhulu futhi inganikezi umuzwa ofiselekayo.
Ngaphezu kwalokho, i-pH nayo ithinta umbala kanye nephunga. Amanye amadayi azwela i-pH futhi angashintsha umbala uma i-pH ishintsha. Lokhu kuthinta umbono wabathengi ngekhwalithi yomkhiqizo.
Ukulawulwa kwe-pH enqubweni yokwenza
Empeleni, ukulawulwa kwe-pH kwenziwa ngezigaba eziningana: ukulinganisa i-pH yezinto zokusetshenziswa, ukulungisa i-pH ngesikhathi sokuxuba, ukuhlola i-pH yomkhiqizo wokugcina, kanye nokuqapha ngesikhathi sokuhlolwa kokuzinza. Imitha ye-pH elinganiswe kahle ibalulekile ukuze kube nemiphumela enembile. Ukulungiswa kwe-pH kuvame ukufezwa ngokungeza i-asidi (isb., i-citric acid noma i-lactic acid) noma isisekelo (isb., i-sodium hydroxide noma i-triethanolamine), njengoba kudingeka.
Noma kunjalo, izinguquko ze-pH akufanele zenziwe ngokungahleliwe. Ukulungisa ngokushesha kakhulu noma ngaphandle kokuhlolwa kokuhambisana kungabangela ukusabela okungafuneki, kushintshe ukuthungwa, noma kunciphise ukusebenza kahle kwezithako ezisebenzayo. Ngakho-ke, ukwakheka kwesimanje kusekelwa njalo yizifundo zangaphambi kokwakheka kanye nokuhlolwa kokuqina okulawulwayo.
Isiphetho
I-pH iyipharamitha ebalulekile ethonya cishe zonke izici zokwakheka komkhiqizo: kusukela ekuqineni nasekuncibilikeni kwesithako esisebenzayo, ukusebenza kahle kokulondoloza, ukuqina kwe-emulsion noma kwejeli, kuya ekuphepheni nasekusebenziseni kalula. Ukulungiswa kwe-pH okufanele kuwumphumela wokucabangela kwesayensi okubandakanya izakhiwo zamakhemikhali zesithako esisebenzayo, izinto ezisizayo, ukusetshenziswa okuhlosiwe, kanye nezindinganiso zekhwalithi yomkhiqizo.
Ngokuqonda ngokuphelele ithonya le-pH, abakhiqizi bangakhiqiza amalungiselelo angagcini nje ngokwelapha noma ngokusebenza kahle, kodwa futhi azinzile ngesikhathi sokugcina futhi aphephile kubasebenzisi. Ekugcineni, ukulawula i-pH akuyona nje isinyathelo sobuchwepheshe, kodwa kuyisu elibalulekile elinquma ikhwalithi nempumelelo yomkhiqizo emakethe.
