I-Polytetrafluoroethylene (i-polytetrafluoroethylene) cishe iyona fluoropolymer esetshenziswa kakhulu ngoba inezici eziningana ezenza ibe yinto efanelekile yokusetshenziswa okubanzi. Iguquguquka kakhulu kunezinye izipayipi ezifanayo futhi ingamelana cishe nawo wonke amakhemikhali ezimboni.
Ibanga lokushisa licishe libe ngu-330°F kuya ku-500°F, okuhlinzeka ngebanga lokushisa elibanzi kakhulu phakathi kwama-fluoropolymers. Ngaphezu kwalokho, inezakhiwo zikagesi ezinhle kakhulu kanye nokuvuleka okuphansi kwamagnetic. I-Ptfe tube iyipayipi lelebhu elisetshenziswa kakhulu kanye nezicelo lapho ukumelana namakhemikhali kanye nobumsulwa kubalulekile khona.I-PTFEine-coefficient ephansi kakhulu yokungqubuzana futhi ingenye yezinto "ezishelelayo" ezaziwayo kakhulu
Izici:
I-resin ye-PTFE emsulwa engu-100%
Uma kuqhathaniswa namapayipi e-FEP, PFA, HP PFA, UHP PFA, ETFE, ECTFE, aguquguqukayo kakhulu e-fluoropolymer
Ayisebenzi ngamakhemikhali, imelana cishe nawo wonke amakhemikhali ezimboni kanye nezinyibilikisi
Ububanzi bokushisa obubanzi
Ukungena okuphansi
Ukuqeda okubushelelezi okunamathelayo
Isilinganiso sokungqubuzana esiphansi kakhulu
Ukusebenza kahle kakhulu kagesi
Ayishisi
Akunabo ubuthi
Izicelo:
ilebhu
Inqubo yamakhemikhali
Ukuhlaziya kanye nemishini yenqubo
Ukuqapha ukukhishwa komoya
Izinga lokushisa eliphansi
izinga lokushisa eliphezulu
Ugesi
i-ozone
Isakhiwo sama-molecule e-PTFE
I-Polytetrafluoroethylene (PTFE) yenziwa yi-polymerization yama-molecule amaningi e-tetrafluoroethylene
Lo mdwebo olula we-PTFE awubonisi isakhiwo se-molecule esinezinhlangothi ezintathu. Ku-poly(ethylene) elula yama-molecule, umgogodla we-carbon we-molecule uxhunywe kuphela ngama-athomu e-hydrogen, futhi lolu chungechunge luguquguquka kakhulu - ngokuqinisekile aluyona i-molecule eqondile.
Kodwa-ke, ku-polytetrafluoroethylene, i-athomu ye-fluorine eqenjini le-CF2 inkulu ngokwanele ukuphazamisa i-athomu ye-fluorine eqenjini eliseduze. Kufanele ukhumbule ukuthi i-athomu ngayinye ye-fluorine inama-electron amathathu aphumayo.
Umphumela walokhu ukucindezela ukujikeleza kwesibopho esisodwa sekhabhoni nekhabhoni. Ama-athomu e-fluorine avame ukuhlelwa ngendlela yokuthi abe kude ngangokunokwenzeka nama-athomu e-fluorine aseduze. Ukujikeleza kuvame ukubandakanya ukushayisana kwe-lone-pair phakathi kwama-athomu e-fluorine kuma-athomu e-carbon aseduze - okwenza ukujikeleza kube kubi kakhulu.
Amandla axoshayo avala i-molecule ibe yisimo senduku, kanti ama-athomu e-fluorine ahlelwe ngendlela ejikelezayo emnene kakhulu—ama-athomu e-fluorine ahlelwe ngendlela ejikelezayo ezungeze umgogodla we-carbon. Lawa ma-lead strips azocindezelwa ndawonye njengamapensela amade, amancane ebhokisini.
Lolu hlelo lokuxhumana oluseduze lunethonya elibalulekile emandleni aphakathi kwama-molecule, njengoba uzobona
Amandla aphakathi kwama-molecule kanye nendawo yokuncibilika kwe-PTFE
Iphuzu lokuncibilika kwe-polytetrafluoroethylene licashunwe njengo-327°C. Lokhu kuphakeme kakhulu kule polymer, ngakho-ke kumele kube namandla amakhulu e-van der Waals phakathi kwama-molecule.
Kungani abantu bethi amandla e-van der Waals ku-PTFE abuthakathaka?
Amandla okusabalala kwe-van der Waals abangelwa ama-dipole ashintshashintshayo okwesikhashana akhiqizwa lapho ama-electron aku-molecule ehambahamba. Ngenxa yokuthi i-molecule ye-PTFE inkulu, ungalindela amandla amakhulu okusabalala ngoba kunama-electron amaningi angahamba.
Isimo esijwayelekile ukuthi lapho i-molecule inkulu, amandla okuhlakazeka ayanda
Kodwa-ke, i-PTFE inenkinga. I-Fluorine ayisebenzi kahle kakhulu. Ivame ukubopha ama-electron ebhondini le-carbon-fluorine ndawonye ngokuqinile, kangangokuthi ama-electron awakwazi ukuhamba njengoba ucabanga. Sichaza ibhondi le-carbon-fluorine njengengenalo i-polarization eqinile.
Amandla e-Van der Waals ahlanganisa nokusebenzisana kwe-dipole-dipole. Kodwa ku-polytetrafluoroethylene (PTFE), i-molecule ngayinye izungezwe ungqimba lwama-athomu e-fluorine ashajwe kabi kancane. Kulokhu, okuwukuphela kokuxhumana okungenzeka phakathi kwama-molecule ukuxoshwa okuhambisanayo!
Ngakho-ke amandla okusabalala abuthakathaka kunalokho ocabanga, futhi ukusebenzisana kwe-dipole-dipole kuzobangela ukuxoshwa. Akumangalisi ukuthi abantu bathi amandla e-van der Waals ku-PTFE abuthakathaka kakhulu. Ngeke uthole amandla okuxoshwa empeleni, ngoba ithonya lamandla okusabalala likhulu kunelokusebenzisana kwe-dipole-dipole, kodwa umphumela ophelele ukuthi amandla e-van der Waals azothambekela ekubeni buthaka.
Kodwa i-PTFE inezinga lokuncibilika eliphezulu kakhulu, ngakho-ke amandla ahlanganisa ama-molecule kumele abe namandla kakhulu.
I-PTFE ingaba kanjani nendawo yokuncibilika ephezulu?
I-PTFE ikristali kakhulu, ngalomqondo kunendawo enkulu, ama-molecule ahlelwe ngendlela ejwayelekile kakhulu. Khumbula, ama-molecule e-PTFE angacatshangwa njengezinduku ezinde. Lezi zinsika zizohlanganiswa eduze.
Lokhu kusho ukuthi nakuba i-molecule ye-ptfe ingakwazi ukukhiqiza ama-dipole amakhulu esikhashana, ama-dipole angasetshenziswa kahle kakhulu.
Ngakho-ke ingabe amandla e-van der Waals ku-PTFE abuthakathaka noma aqinile?
Ngicabanga ukuthi nobabili ningaba neqiniso! Uma amaketanga e-polytetrafluoroethylene (PTFE) ehlelwe ngendlela yokuthi kungabikho ukuxhumana okuseduze kakhulu phakathi kwamaketanga, amandla aphakathi kwawo azoba buthakathaka kakhulu futhi iphuzu lokuncibilika lizoba liphansi kakhulu.
Kodwa emhlabeni wangempela, ama-molecule asondelene kakhulu. Amandla e-Van der Waals angase angabi namandla njengoba engaba nawo, kodwa isakhiwo se-PTFE sisho ukuthi azizwa umphumela omkhulu, ekhiqiza izibopho eziqinile phakathi kwama-molecule kanye namaphuzu aphezulu okuncibilika.
Lokhu kuphambene namanye amandla, njenge-dipole-dipole interaction force, encishiswa kuphela izikhathi ezingu-23, noma kabili ibanga elincishiswa izikhathi ezingu-8.
Ngakho-ke, ukupakisha okuqinile kwama-molecule anjengenduku ku-PTFE kukhulisa ukusebenza kahle kokuhlakazeka
Izakhiwo ezinganamatheli
Yingakho amanzi namafutha kunganamatheli ebusweni be-PTFE, futhi kungani ungathosa amaqanda epanini elimbozwe yi-PTFE ngaphandle kokunamathela epanini.
Udinga ukucabangela ukuthi yimaphi amandla angalungisa amanye ama-molecule ebusweni be-I-PTFEKungafaka uhlobo oluthile lwesibopho samakhemikhali, amandla e-van der Waals noma isibopho se-hydrogen
Ukubopha kwamakhemikhali
Isibopho se-carbon-fluorine sinamandla kakhulu, futhi akunakwenzeka ukuthi amanye ama-molecule afinyelele uchungechunge lwe-carbon ukuze abangele noma yikuphi ukusabela kokushintshana kwenzeke. Akunakwenzeka ukuthi isibopho samakhemikhali senzeke
amabutho e-van der Waals
Sibonile ukuthi amandla e-van der Waals ku-PTFE awanamandla kakhulu, futhi azokwenza i-PTFE ibe nephuzu lokuncibilika eliphezulu, ngoba ama-molecule asondelene kakhulu kangangokuthi anokuxhumana okuphumelelayo kakhulu.
Kodwa kuhlukile kwamanye ama-molecule aseduze nobuso be-PTFE. Ama-molecule amancane kakhulu (njengama-molecule amanzi noma ama-molecule kawoyela) azoba nenani elincane lokuxhumana nobuso, futhi kuzokhiqizwa inani elincane kuphela lokukhanga kwe-van der Waals.
I-molecule enkulu (njengeprotheni) ngeke ibe nesimo senduku, ngakho-ke akukho ukuxhumana okwanele okusebenzayo phakathi kwayo nendawo ukuze kunqotshwe ukuthambekela okuphansi kokuhlukaniswa kwe-PTFE.
Noma ngabe yikuphi, amandla e-van der Waals phakathi kobuso be-PTFE nezinto ezizungezile mancane futhi awasebenzi kahle.
Izibopho ze-hydrogen
Ama-molecule e-PTFE angaphezulu ahlanganiswe ngokuphelele ngama-athomu e-fluorine. Lawa ma-athomu e-fluorine ane-electronegative kakhulu, ngakho-ke wonke athwala izinga elithile lokushaja okungekuhle. I-fluorine ngayinye inama-elektroni amabili aphumayo amathathu.
Lezi yizimo ezidingekayo ekwakhekeni kwezibopho ze-hydrogen, njenge-lone pair ku-fluorine kanye ne-athomu ye-hydrogen emanzini. Kodwa lokhu kusobala ukuthi ngeke kwenzeke, ngaphandle kwalokho kuzoba nokukhangana okunamandla phakathi kwama-molecule e-PTFE nama-molecule amanzi, futhi amanzi azonamathela ku-PTFE.
Isifinyezo
Ayikho indlela ephumelelayo yokuthi amanye ama-molecule anamathele ngempumelelo ebusweni be-PTFE, ngakho-ke inobuso obunganamatheli.
Ukungqubuzana okuphansi
I-coefficient of friction ye-PTFE iphansi kakhulu. Lokhu kusho ukuthi uma unomphezulu ombozwe nge-ptfe, ezinye izinto zizoshelela kalula kuwo.
Ngezansi kunesifinyezo esifushane salokho okwenzekayo. Lokhu kuvela ephepheni lika-1992 elinesihloko esithi "Ukungqubuzana Nokugqokwa Kwe-Polytetrafluoroethylene".
Ekuqaleni kokushelela, ubuso be-PTFE buyaphuka bese isisindo sidluliselwa noma kuphi lapho sishelela khona. Lokhu kusho ukuthi ubuso be-PTFE buzoguga.
Njengoba ukushelela kuqhubeka, amabhlogo avuleka aba amafilimu amancane.
Ngesikhathi esifanayo, ubuso be-PTFE buyakhishwa ukuze bakhe ungqimba oluhlelekile.
Zombili izindawo ezithintanayo manje zinama-molecule e-PTFE ahlelwe kahle angashelelana
Lokhu okungenhla ukwethulwa kwe-polytetrafluoroethylene, i-polytetrafluoroethylene ingenziwa ibe imikhiqizo ehlukahlukene, sikhethekile ekwenzeni i-ptfe tube,abakhiqizi bepayipi le-ptfe, wamukelekile ukuxhumana nathi
Usesho oluhlobene nepayipi le-ptfe:
Isikhathi sokuthunyelwe: Meyi-05-2021