Izici, ukulungiswa kanye nokusetshenziswa kwe-cellulose ether embonini

Izinhlobo, izindlela zokulungiselela, izakhiwo kanye nezici ze-cellulose ether zabuyekezwa, kanye nokusetshenziswa kwe-cellulose ether ku-petroleum, ukwakhiwa, ukwenza iphepha, izindwangu, imithi, ukudla, izinto ze-photoelectric kanye nomkhakha wamakhemikhali wansuku zonke.Ezinye izinhlobo ezintsha zokuphuma kokunye okuphuma ku-cellulose ether okunamathemba okuthuthuka kwethulwa futhi amathuba okusebenza kwazo athuthukiswa.

Amagama angukhiye:i-cellulose ether;Ukusebenza;Isicelo;Okuphuma ku-cellulose

I-Cellulose uhlobo lwenhlanganisela ye-polymer yemvelo.Ukwakheka kwayo kwamakhemikhali kuyi-polysaccharide macromolecule ene-β-glucose engenahydrous njengendandatho yesisekelo, eneqembu elilodwa eliyinhloko le-hydroxyl kanye namaqembu amabili esibili e-hydroxyl iringi ngayinye yesisekelo.Ngokuguqulwa kwamakhemikhali, uchungechunge lwe-cellulose derivatives lungatholakala, i-cellulose ether ingenye yazo.I-cellulose ether itholakala ngokusabela kwe-cellulose ne-NaOH, bese i-etherize ngama-monomers ahlukahlukene asebenzayo njenge-methane chloride, i-ethylene oxide, i-propylene oxide, njll., ngokugeza usawoti womkhiqizo kanye ne-sodium cellulose.I-cellulose ether iyingxenye ebalulekile ye-cellulose, ingasetshenziswa kabanzi kwezokwelapha nempilo, amakhemikhali nsuku zonke, iphepha, ukudla, imithi, ukwakhiwa, izinto zokwakha kanye nezinye izimboni.Ngakho-ke, ukuthuthukiswa nokusetshenziswa kwe-cellulose ether kunokubaluleka okuhle ekusetshenzisweni okuphelele kwemithombo ye-biomass evuselelekayo, ukuthuthukiswa kwezinto ezintsha kanye nobuchwepheshe obusha.

1. Ukuhlukaniswa nokulungiswa kwe-cellulose ether

Ukuhlukaniswa kwama-cellulose ethers ngokuvamile kuhlukaniswa ngezigaba ezine ngokuya ngezakhiwo zawo ze-ionic.

1.1 I-nonionic cellulose ether

I-non-ionic cellulose ether ikakhulukazi i-cellulose alkyl ether, indlela yokulungiselela i-cellulose kanye nokusabela kwe-NaOH, bese kuba nama-monomer ahlukahlukene asebenzayo njenge-methane chloride, i-ethylene oxide, i-propylene oxide etherification reaction, bese-ke ngokugeza umkhiqizo ophumayo. usawoti kanye ne-sodium cellulose ukuthola.I-methyl cellulose ether eyinhloko, i-methyl hydroxyethyl cellulose ether, i-methyl hydroxypropyl cellulose ether, i-hydroxyethyl cellulose ether, i-cyanoethyl cellulose ether, i-hydroxybutyl cellulose ether.Ukusetshenziswa kwayo kubanzi kakhulu.

1.2 I-anionic cellulose ether

I-Anionic cellulose ether ngokuyinhloko i-carboxymethyl cellulose sodium, i-carboxymethyl hydroxyethyl cellulose sodium.Indlela yokulungiselela iwukuba ngokusabela kwe-cellulose ne-NaOH, bese i-etherify nge-monochloroacetic acid noma i-ethylene oxide, i-propylene oxide, bese ugeza usawoti womkhiqizo kanye ne-sodium cellulose ukuze uthole.

1.3 i-cationic cellulose ether

I-Cationic cellulose ether ikakhulukazi i-3 – chlorine – 2 – hydroxypropyl trimethyl ammonium chloride cellulose ether.Indlela yokulungiselela iwukusabela kwe-cellulose ne-NaOH, bese kuba i-cationic etherifying agent 3 – chlorine – 2 – hydroxypropyl trimethyl ammonium chloride noma i-ethylene oxide, i-propylene oxide kanye nokusabela kwe-etherifying, bese ngokugeza usawoti womkhiqizo nesodium. cellulose ukuthola.

1.4 IZwitterionic cellulose ether

I-Zwitterionic cellulose ether inawo womabili amaqembu e-anionic namaqembu e-cationic ochungechungeni lwamangqamuzana, indlela yokulungiselela iwukuba nge-cellulose kanye nokusabela kwe-NaOH, bese kuba ne-chloroacetic acid kanye ne-cationic etherifying agent 3 – chlorine – 2 hydroxypropyl trimethyl ammonium chloride etherification reaction, bese igezwa. ngomkhiqizo kasawoti kanye ne-sodium cellulose futhi yatholakala.

2.izakhiwo nezici ze-cellulose ether

2.1 Izici zokubukeka

I-Cellulose ether ngokuvamile imhlophe noma i-milky white, ayinambitheki, ayinabo ubuthi, inoketshezi lwempushana ene-fibrous, imunca umswakama kalula, incibilike emanzini ibe i-colloid esobala ye-viscous ezinzile.

2.2 Ukwakhiwa kwefilimu nokunamathela

I-etherification ye-cellulose ether inethonya elikhulu ezintweni zayo, njengokuncibilika, ikhono lokwenza ifilimu, amandla ebhondi kanye nokubekezelelana kukasawoti.I-Cellulose ether inamandla amakhulu emishini, ukuguquguquka, ukumelana nokushisa nokumelana nokubanda, futhi inokuhambisana okuhle nezinhlobonhlobo zama-resin nama-plasticizers, ingasetshenziswa ukwenza amapulasitiki, amafilimu, ama-varnishes, ama-adhesives, i-latex kanye nezinto zokugqoka zemithi.

2.3 Ukunyibilika

I-methyl cellulose encibilika emanzini abandayo, ayincibiliki emanzini ashisayo, kodwa futhi incibilika kwezinye izinyibilikisi eziphilayo;I-Methyl hydroxyethyl cellulose inyibilika emanzini abandayo, ayincibiliki emanzini ashisayo nasezithanjeni zemvelo.Kodwa uma isixazululo esinamanzi se-methyl cellulose ne-methyl hydroxyethyl cellulose sishisiswa, i-methyl cellulose ne-methyl hydroxyethyl cellulose izokwehla.I-Methyl cellulose idonse ku-45 ~ 60 ℃, kuyilapho i-ethyl hydroxyethyl cellulose exubile yenyuka ngo-65 ~ 80℃.Lapho izinga lokushisa lehla, imvula iyancibilika kabusha.

I-sodium hydroxyethyl cellulose ne-carboxymethyl hydroxyethyl cellulose zincibilika emanzini kunoma yiliphi izinga lokushisa, kodwa azincibiliki kuzinyibilikisi zemvelo (ngaphandle kokumbalwa).

2.4 Ukuqina

I-cellulose ether incibilika emanzini ngesimo se-colloidal, futhi i-viscosity yayo incike ezingeni le-polymerization ye-cellulose ether.Isixazululo siqukethe ama-macromolecules we-hydration.Ngenxa yokugxambukela kwama-macromolecules, indlela yokugeleza kwesisombululo ihlukile kuleyo yoketshezi lwaseNewtonian, kodwa ibonisa ukuziphatha okuhlukayo ngokushintsha kwamandla okugunda.Ngenxa yokwakheka kwe-macromolecular ye-cellulose ether, i-viscosity yesisombululo ikhula ngokushesha ngokugxila okukhulayo futhi yehla ngokushesha ngokukhuphuka kwezinga lokushisa.

2.5 Ukuwohloka

I-cellulose ether isetshenziswa esigabeni se-aqueous.Uma nje amanzi esekhona, amagciwane azokhula.Ukukhula kwamabhaktheriya kuholela ekukhiqizweni kwamabhaktheriya e-enzyme.Ibhaktheriya ye-enzyme yenza ibhondi yeyunithi ye-glucose ephelelwe amanzi engashintshiwe eduze nekhefu le-cellulose ether kanye nesisindo samangqamuzana e-polymer sehla.Ngakho-ke, uma isixazululo samanzi se-cellulose ether kufanele sigcinwe isikhathi eside, isilondolozi kufanele sengezwe kuso, ngisho noma kusetshenziswa i-antibacterial cellulose ether.

3.ukusetshenziswa kwe-cellulose ether embonini

3.1 Imboni kawoyela

I-sodium carboxymethyl cellulose isetshenziswa kakhulu ekuxhashazweni kwe-petroleum.Isetshenziselwa ukwakhiwa kodaka ukuze kwandiswe i-viscosity nokunciphisa ukulahlekelwa kwamanzi.Ingakwazi ukumelana nokungcola okuhlukahlukene kukasawoti oncibilikayo futhi ithuthukise izinga lokuthola kabusha uwoyela.

I-sodium carboxymethyl hydroxypropyl cellulose kanye ne-sodium carboxymethyl hydroxyethyl cellulose wuhlobo lwe-ejenti yokwelapha yodaka engcono yokumba nokulungisa izinto eziwuketshezi, izinga eliphezulu lokudonsa, ukumelana nosawoti, ukumelana ne-calcium, ikhono elihle le-viscosification, ukumelana nezinga lokushisa (160℃).Ilungele ukulungiswa kwamanzi ahlanzekile, amanzi olwandle kanye noketshezi lokumba lwamanzi anosawoti agcwele, ngaphansi kwesisindo se-calcium chloride ingaxutshwa ezinhlobonhlobo zokuminyana (103 ~ 1279 / cm3) uketshezi lokumba, futhi ikwenze kube ne-viscosity ethile kanye nokuhlunga okuphansi. umthamo, i-viscosity yayo kanye namandla okuhlunga angcono kune-hydroxyethyl cellulose, iyizithasiselo ezinhle zokukhiqiza uwoyela.I-sodium carboxymethyl cellulose isetshenziswa kabanzi enqubweni yokuxhashazwa kwe-petroleum ye-cellulose derivatives, ekubambeni uketshezi, uketshezi lukasimende, uketshezi lwe-fracturing nokuthuthukisa ukukhiqizwa kukawoyela kusetshenziswa, ikakhulukazi ekusetshenzisweni koketshezi lokumba kukhulu, ukukhumula okuyinhloko kanye nokuhlunga kokufika kanye ne-viscosification.

I-Hydroxyethyl cellulose isetshenziswa enqubweni yokumba, ukuqedwa kanye nokufaka usimende njengendlela yokuqinisa udaka.Ngenxa yokuthi i-hydroxyethyl cellulose ne-sodium carboxymethyl cellulose, i-guar gum uma iqhathaniswa nomphumela omuhle wokujiya, isihlabathi sokumiswa, okuqukethwe kukasawoti omningi, ukumelana nokushisa okuhle, nokumelana okuncane, ukulahlekelwa okuncane koketshezi, ibhulokhi yerabha ephukile, izici zensalela ephansi, isetshenziswe kabanzi.

3.2 Imboni yezokwakha nokuhlanganisa

Ingxube yesakhiwo sokwakha nokunamathelisa: i-sodium carboxymethyl cellulose ingasetshenziswa njenge-ejenti ebuyisela emuva, i-ejenti yokugcina amanzi, i-thickener ne-binder, ingasetshenziswa njenge-gypsum phansi kanye nosimende ophansi, udaka kanye ne-ground leveling material, i-ejenti yokugcina amanzi, i-thickener.Kuwuhlobo lwenhlanganisela yodaka olukhethekile lwamatshe kanye nodaka lwamabhulokhi kakhonkolo ane-aerated enziwe nge-carboxymethyl cellulose, engathuthukisa ukusebenza, ukugcinwa kwamanzi kanye nokumelana nokuqhekeka kodaka futhi igweme ukuqhekeka nokungena odongeni lwebhulokhi.

Izinto zokwakha zokuhlobisa ubuso: I-Cao Mingqian kanye nezinye i-methyl cellulose ezenziwe ngohlobo lwezinto zokuhlobisa ukuvikelwa kwemvelo, inqubo yayo yokukhiqiza ilula, ihlanzekile, ingasetshenziselwa udonga lwezinga eliphezulu, i-tile surface, ingasetshenziswa futhi ikholomu. , ukuhlobisa kwendawo yethebhulethi.I-Huang Jianping eyenziwe nge-carboxymethyl cellulose iwuhlobo lwe-ceramic tile sealant, enamandla okubopha okuqinile, ikhono elihle lokuguga, ayikhiqizi imifantu futhi iwa, umphumela omuhle ongangeni manzi, umbala ogqamile nonemibalabala, nomphumela omuhle kakhulu wokuhlobisa.

Ukusetshenziswa kwezingubo zokugqoka: I-Methyl cellulose ne-hydroxyethyl cellulose ingasetshenziswa njenge-stabilizer, i-thickener kanye ne-ejenti yokugcina amanzi yezingubo ze-latex, ngaphezu kwalokho, ingasetshenziswa njenge-dispersant, i-viscosifier kanye ne-ejenti yokwenza ifilimu yezingubo zikasimende ezinemibala.Ukwengeza i-cellulose ether enezincazelo ezifanele kanye ne-viscosity kupende we-latex kungathuthukisa ukusebenza kokwakhiwa kopende we-latex, kuvimbele isipatha, kuthuthukise ukuzinza kwesitoreji namandla ekhava.Inkambu eyinhloko yabathengi phesheya i-latex coatings, ngakho-ke, imikhiqizo ye-cellulose ether ngokuvamile iba yisinqumo sokuqala se-latex paint thickener.Isibonelo, i-methyl hydroxyethyl cellulose ether eguquliwe ingagcina indawo ehamba phambili ku-thickener kapende we-latex ngenxa yezindawo zayo ezinhle ezihlanganisayo.Isibonelo, ngenxa yokuthi i-cellulose ether inezici zejeli ezishisayo ezihlukile kanye nokuncibilika, ukumelana nosawoti, ukumelana nokushisa, futhi inomsebenzi ofanele ongaphezulu, ingasetshenziswa njenge-ejenti yokugcina amanzi, i-ejenti yokumiswa, i-emulsifier, i-ejenti eyenza ifilimu, i-lubricant, i-binder kanye nokuchitshiyelwa kwe-rheological. .

3.3 Imboni Yamaphepha

Izithasiselo ezimanzi zephepha: I-CMC ingasetshenziswa njenge-fiber dispersant kanye nesithuthukisi sephepha, ingangezwa ku-pulp, ngoba i-sodium carboxymethyl cellulose kanye ne-pulp kanye nezinhlayiya zokupakisha zinenani elifanayo, zingandisa ukulingana kwefayibha, zithuthukise amandla iphepha.Njenge-reinforcer engezwe ngaphakathi kwephepha, ikhulisa ukubambisana kwesibopho phakathi kwemicu, futhi ingathuthukisa amandla aqinile, ukumelana nekhefu, ukulingana kwephepha nezinye izinkomba zomzimba.I-sodium carboxymethyl cellulose ingasetshenziswa njenge-ejenti yokulinganisa ku-pulp.Ngaphezu kweziqu zayo zokulinganisa, ingasetshenziswa futhi njenge-ejenti evikelayo ye-rosin, i-AKD namanye ama-ejenti wokulinganisa.I-Cationic cellulose ether ingasetshenziswa futhi njengesihlungi sokusiza ukugcina iphepha, ithuthukise izinga lokugcinwa kwefayibha ecolekile nesigcwalisi, ingasetshenziswa futhi njengokuqinisa iphepha.

Ingcina yokunamathisela: Isetshenziselwa ukunamathisela ukucubungula iphepha lokunamathisela ingcina, ingathatha indawo kashizi, ingxenye ye-latex, ukuze uyinki wokunyathelisa ungene kalula, onqenqemeni olucacile.Ingasetshenziswa futhi njenge-pigment dispersant, i-viscosifier kanye ne-stabilizer.

I-ejenti yokulinganisa ubuso: I-sodium carboxymethyl cellulose ingasetshenziswa njenge-ejenti yokulinganisa ubuso bephepha, ithuthukise amandla ephepha, uma iqhathaniswa nokusetshenziswa kwamanje kotshwala be-polyvinyl, isitashi esiguquliwe ngemuva kokuthi amandla angaphezulu angakhuphuka cishe ngo-10%, umthamo uyancipha. cishe ngama-30%.Kuyi-ejenti ethembisayo yokulinganisa indawo yokwenza iphepha, futhi uchungechunge lwayo lwezinhlobo ezintsha kufanele luthuthukiswe ngenkuthalo.I-Cationic cellulose ether inokusebenza okungcono kokulinganisa kwendawo kunesitashi se-cationic, ayigcini nje ngokuthuthukisa amandla angaphezulu ephepha, kodwa futhi ingathuthukisa ukumuncwa kukayinki wephepha, ikhulise umphumela wokudaya, iphinde ibe i-ejenti ethembisayo yokulinganisa indawo.

3.4 Imboni yezindwangu

Embonini yendwangu, i-cellulose ether ingasetshenziswa njenge-ejenti yokulinganisa, i-ejenti yokulinganisa kanye ne-ejenti yokuqina ye-pulp yendwangu.

I-ejenti yokulinganisa: i-cellulose ether efana ne-sodium carboxymethyl cellulose, i-hydroxyethyl carboxymethyl cellulose ether, i-hydroxypropyl carboxymethyl cellulose ether nezinye izinhlobo zingasetshenziswa njenge-ejenti yokulinganisa, futhi akulula ukuwohloka nokubunjwa, ukuphrinta nokudaya, ngaphandle kokudaya, ukukhuthaza udayi kungathola umfaniswano. colloid emanzini.

I-ejenti yokulinganisa: ingathuthukisa amandla we-hydrophilic kanye ne-osmotic kadayi, ngoba ukuguqulwa kwe-viscosity kuncane, kulula ukulungisa umehluko wombala;I-Cationic cellulose ether nayo inomphumela wokudaya nemibala.

I-ejenti ejiyayo: i-sodium carboxymethyl cellulose, i-hydroxyethyl carboxymethyl cellulose ether, i-hydroxypropyl carboxymethyl cellulose ether ingasetshenziswa njenge-ejenti yokunyathelisa nokudaya ukuqina kwe-slurry, enensalela encane, izici zezinga eliphezulu lombala, ikilasi lezithasiselo zendwangu ezingaba khona kakhulu.

3.5 Imboni yamakhemikhali asekhaya

I-viscosifier eqinile: I-sodium methylcellulose emikhiqizweni yokunamathisela yezinto ezingavuthiwe eziyimpushana idlala ukuzinza kokumiswa kokuhlakazeka, kuzimonyo eziwuketshezi noma ze-emulsion ziyajiya, zihlakaze, zibe ne-homogenizing nezinye izindima.Ingasetshenziswa njenge-stabilizer ne-viscosifier.

I-Emulsifying stabilizer: yenza amafutha okugcoba, i-shampoo emulsifier, i-ejenti yokuqina kanye ne-stabilizer.I-sodium carboxymethyl hydroxypropyl cellulose ingasetshenziswa njenge-adhesive stabilizer ye-toothpaste, enezici ezinhle ze-thixotropic, ukuze umuthi wokuxubha ube nokuhleleka okuhle, ukuguqulwa kwesikhathi eside, ukunambitheka okufanayo nokuthambile.I-sodium carboxymethyl hydroxypropyl cellulose ukumelana nosawoti, ukumelana ne-asidi kuphakeme, umphumela ungcono kakhulu kune-carboxymethyl cellulose, ingasetshenziswa njengesihlanzi ku-viscosifier, i-ejenti yokuvimbela okunamathiselwe kokungcola.

I-Dispersion thickener: Ekukhiqizeni okokuhlanza, ukusetshenziswa okuvamile kwe-sodium carboxymethyl cellulose njenge-dipersant yokungcola yokuhlanza okokuhlanza, okokuhlanza okuwuketshezi kanye ne-dispersant.

3.6 Izimboni zemithi nezokudla

Embonini yezemithi, i-hydroxypropyl carboxymethyl cellulose ingasetshenziswa njengama-excipients ezidakamizwa, esetshenziswa kabanzi ekukhululweni okulawulwa kwamathambo ezidakamizwa ngomlomo kanye namalungiselelo okukhululwa okuqhubekayo, njengento evimbela ukukhululwa ukuze ulawule ukukhululwa kwezidakamizwa, njenge-coating material yokukhululwa okuqhubekayo, ama-pellets okukhululwa okuqhubekayo. , ama-capsules okukhululwa okuqhubekayo.Okusetshenziswa kakhulu i-methyl carboxymethyl cellulose, i-ethyl carboxymethyl cellulose, efana ne-MC ivame ukusetshenziswa ekwenzeni amaphilisi namaphilisi, noma amaphilisi ambozwe ngoshukela.

Ikhwalithi yekhwalithi ye-cellulose ether ingasetshenziswa embonini yokudla, ekudleni okuhlukahlukene i-ejenti yokuqina ephumelelayo, i-emulsifier, i-stabilizer, i-excipient, i-ejenti yokugcina amanzi kanye ne-ejenti yokugwedla.I-Methyl cellulose ne-hydroxypropyl methyl cellulose kuye kwaqashelwa njengezinto ezingenabungozi ze-metabolic.Ukuhlanzeka okuphezulu (99.5% noma ngaphezulu ukuhlanzeka) i-carboxymethyl cellulose ingafakwa ekudleni, njengobisi nemikhiqizo kakhilimu, izinongo, ujamu, ijeli, amathini, ama-syrups etafuleni neziphuzo.Ukuhlanzeka kwe-carboxymethyl cellulose engaphezu kuka-90% kungasetshenziswa ezicini ezihlobene nokudla, ezifana nokusetshenziswa ekuthuthweni nasekugcinweni kwezithelo ezintsha, ukugoqa kwepulasitiki kunomphumela omuhle wokulondoloza, ukungcola okuncane, akukho monakalo, izinzuzo zokukhiqiza ezitholakala kalula.

3.7 Izinto ezisebenza ngokukhanya nezikagesi

I-Electrolyte thickening stabilizer: ngenxa yokuhlanzeka okuphezulu kwe-cellulose ether, ukumelana ne-asidi enhle, ukumelana nosawoti, ikakhulukazi insimbi kanye nokuqukethwe kwensimbi esindayo kuphansi, ngakho-ke i-colloid izinzile kakhulu, ifanele ibhethri ye-alkali, ibhethri ye-zinc manganese i-electrolyte thickening stabilizer.

I-Liquid crystal materials: Kusukela ngo-1976, ukutholakala kokuqala kwe-hydroxypropyl cellulose - i-water system liquid crystal ask phase, itholakale kusixazululo esifanelekile se-organic, izinto eziningi eziphuma ku-cellulose ekugxilweni okuphezulu zingakha isisombululo se-anisotropic, isibonelo, i-hydroxypropyl cellulose kanye ne-acetate, i-propionate. , i-benzoate, i-phthalate, i-acetyxyethyl cellulose, i-hydroxyethyl cellulose, njll. Ngaphezu kokwenza i-colloidal ionic liquid crystal solution, amanye ama-ester e-hydroxypropyl cellulose nawo abonisa lesi sici.

Ama-cellulose ether amaningi abonisa izici zekristalu ye-thermotropic liquid.I-Acetyl hydroxypropyl cellulose yenza i-thermogenic cholesteric liquid crystal ngaphansi kwe-164 ℃.I-acetoxyproppropylllls lyroxes, i-trifluoroacetate hydroxypropyllls celtuleose, i-hydroxypropyllluose kanye nezinto zayo zokususelwa, i-ethyl hydroxypropylliccellulose, i-heydlylylylsiliccellulose, i-Extyl cellulose kanye ne-bulloxylesyl cellulose, njll. ., konke kukhombise i-Thermogenic CholeSteric Liquid Crystal.Amanye ama-cellulose esters afana ne-cellulose benzoate, i-p-methoxybenzoate ne-p-methylbenzoate, i-cellulose heptanate ingenza amakristalu e-thermogen cholesteric liquid.

Izinto zokufakelwa kukagesi: i-cyanoethyl cellulose etherifying agent ye-acrylonitrile, izinga layo eliphakeme le-dielectric, i-coefficient yokulahlekelwa okuphansi, ingasetshenziswa njenge-phosphorus ne-electroluminescent resin matrix kanye nokufakwa kwe-transformer.

4. Amazwi Okuvala

Ukusebenzisa ukuguqulwa kwamakhemikhali ukuze uthole okuphuma ku-cellulose ngemisebenzi ekhethekile kuyindlela ephumelelayo yokuthola ukusetshenziswa okusha kwe-cellulose, i-organic matter enkulu kunazo zonke emhlabeni.Njengenye yezinto eziphuma ku-cellulose, i-cellulose ether efana ne-physiological engenangozi, izinto ze-polymer ezincibilikayo ezingenakungcola emanzini ngenxa yezakhiwo zayo ezinhle kakhulu, isisetshenziswe ezimbonini eziningi, futhi izoba nethemba elibanzi lentuthuko.