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Hanyar kunnawa ta jiki da sinadarai
Hanyar kunnawa ta jiki da sinadarai tana nufin hanyar shirya kayan pozzed ta hanyar haɗa hanyoyin kunnawa biyu na sama. Gabaɗaya, ana fara kunna sinadarai ne da farko, sannan kuma ana yin aikin jiki. Da farko soak cellulose a cikin 68% ~ 85% H3PO4 bayani a 85 ℃ na 2h, sa'an nan carbonized shi a cikin muffle tanderun for 4h, sa'an nan kunna shi da CO2. Ƙayyadadden yanki na carbon da aka kunna da aka samu ya kai 3700m2 · g-1. Yi ƙoƙarin yin amfani da sisal fiber a matsayin albarkatun kasa, kuma kunna fiber carbon da aka kunna (ACF) da aka samu ta H3PO4 kunnawa sau ɗaya, mai zafi da shi zuwa 830 ℃ a ƙarƙashin kariya ta N2, sannan amfani da tururin ruwa azaman mai kunnawa don kunnawa na biyu. Ƙayyadadden yanki na ACF da aka samu bayan 60min kunnawa ya inganta sosai.
Halayen aikin tsarin pore na kunnawacarbon
Hanyoyin siffanta aikin carbon da aka yi amfani da su da yawa ana nuna su a cikin Tebur 2. Za'a iya gwada fasalin tsarin pore na kayan daga bangarori biyu: nazarin bayanai da nazarin hoto.
Ci gaban bincike na fasahar inganta tsarin pore na carbon da aka kunna
Ko da yake kunna carbon yana da wadataccen pores da ƙaƙƙarfan yanki na musamman, yana da kyakkyawan aiki a fannoni da yawa. Duk da haka, saboda da fadi da albarkatun kasa selectivity da hadaddun shirye-shirye yanayi, ƙãre kayayyakin kullum da disadvantages na m pore tsarin, daban-daban takamaiman surface area, disordered pore size rarraba, da iyaka surface sinadaran Properties. Saboda haka, akwai rashin amfani kamar babban sashi da kunkuntar daidaitawa a cikin tsarin aikace-aikacen, wanda ba zai iya biyan bukatun kasuwa ba. Sabili da haka, yana da mahimmanci a aikace don ingantawa da daidaita tsarin da inganta ingantaccen amfani da shi. Hanyoyin da aka saba amfani da su don ingantawa da daidaita tsarin pore sun haɗa da ka'idojin sinadarai, haɗakar polymer, da tsarin kunnawa catalytic.
Fasahar sarrafa sinadarai
Chemical tsarin fasaha yana nufin aiwatar da sakandare kunnawa (gyara) na porous kayan samu bayan kunnawa da sinadaran reagents, eroding na asali pores, fadada da micropores, ko kara samar da sabon micropores ƙara da takamaiman surface yankin da pore tsarin na kayan. Gabaɗaya magana, ƙãre samfurin daya kunnawa ne gaba ɗaya nutsewa a cikin 0.5 ~ 4 sau na sinadaran bayani daidaita pore tsarin da kuma ƙara takamaiman surface area. Ana iya amfani da kowane irin acid da alkali mafita azaman reagents don kunnawa na biyu.
Acid surface hadawan abu da iskar shaka gyara fasaha
Acid surface oxidation gyare-gyare hanya ce da aka saba amfani da ita. A yanayin da ya dace, acid oxidants na iya wadatar da pores a cikin carbon da aka kunna, inganta girman ramin sa, da kuma toshe pores. A halin yanzu, bincike na cikin gida da na waje ya fi mayar da hankali kan gyare-gyaren inorganic acid. HN03 oxidant ne da aka saba amfani dashi, kuma malamai da yawa suna amfani da HN03 don gyara carbon da aka kunna. Tong Li et al. [28] gano cewa HN03 na iya ƙara abun ciki na oxygen-dauke da oxygen da nitrogen-dauke da kungiyoyin ayyuka a saman da kunna carbon da inganta adsorption sakamako na mercury.
Gyaran carbon da aka kunna tare da HN03, bayan gyare-gyare, takamaiman yanki na carbon da aka kunna ya ragu daga 652m2 · g-1 zuwa 241m2 · g-1, matsakaicin girman pore ya karu daga 1.27nm zuwa 1.641nm, da ƙarfin adsorption na benzophenone. a simulated man fetur ya karu da 33.7%. Canza itace mai kunna carbon tare da 10% da 70% maida hankali na HN03, bi da bi. Sakamakon ya nuna cewa takamaiman yanki na carbon da aka kunna tare da 10% HN03 ya karu daga 925.45m2 · g-1 zuwa 960.52m2 · g-1; bayan gyare-gyare tare da 70% HN03, ƙayyadadden yanki ya ragu zuwa 935.89m2 · g-1. Yawan cirewar Cu2+ ta hanyar kunna carbon da aka gyara tare da ƙima biyu na HN03 sun kasance sama da 70% da 90%, bi da bi.
Don carbon da aka kunna da aka yi amfani da shi a cikin filin talla, tasirin tallan ya dogara ba kawai akan tsarin pore ba amma har ma akan abubuwan sinadarai na farfajiyar adsorbent. Tsarin pore yana ƙayyade takamaiman yanki da ƙarfin tallan carbon da aka kunna, yayin da kaddarorin sinadarai na saman ke shafar hulɗar tsakanin carbon da aka kunna da adsorbate. A ƙarshe an gano cewa gyare-gyaren acid na carbon da aka kunna ba zai iya daidaita tsarin pore kawai a cikin carbon da aka kunna ba kuma ya share pores da aka katange, amma kuma yana ƙara yawan abun ciki na kungiyoyin acidic a saman kayan da haɓaka polarity da hydrophilicity na farfajiya. . Ƙarfin adsorption na EDTA ta hanyar carbon da aka kunna ta HCI ya karu da 49.5% idan aka kwatanta da wancan kafin gyara, wanda ya fi na HNO3 gyara.
Canja wurin kasuwancin da aka kunna carbon tare da HNO3 da H2O2 bi da bi! Ƙayyadaddun wurare na musamman bayan gyare-gyare sun kasance 91.3% da 80.8% na waɗanda kafin gyara, bi da bi. Sabbin ƙungiyoyin ayyuka masu ɗauke da iskar oxygen kamar carboxyl, carbonyl da phenol an ƙara su zuwa saman. Ƙarfin adsorption na nitrobenzene ta HNO3 gyare-gyare shine mafi kyau, wanda shine sau 3.3 kafin gyare-gyare. An gano cewa karuwa a cikin abun ciki na ƙungiyoyi masu aiki na oxygen a cikin carbon da aka kunna bayan gyare-gyaren acid ya haifar da karuwa a yawan adadin saman. maki masu aiki, wanda ke da tasiri kai tsaye akan inganta ƙarfin tallan tallan tallan.
Idan aka kwatanta da inorganic acid, akwai 'yan rahotanni kan gyare-gyaren kwayoyin acid na carbon da aka kunna. Kwatanta tasirin gyare-gyaren kwayoyin acid akan kaddarorin tsarin pore na carbon da aka kunna da kuma tallan methanol. Bayan gyare-gyare, ƙayyadaddun wuri na musamman da jimlar ƙarar ƙura na carbon da aka kunna ya ragu. Mafi ƙarfin acidity, mafi girma raguwa. Bayan gyare-gyare tare da oxalic acid, tartaric acid da citric acid, ƙayyadaddun yanki na carbon da aka kunna ya ragu daga 898.59m2 · g-1 zuwa 788.03m2 · g-1, 685.16m2 · g-1 da 622.98m2 · g-1 bi da bi. Koyaya, microporosity na carbon da aka kunna ya karu bayan gyare-gyare. Microporosity na carbon da aka kunna tare da citric acid ya karu daga 75.9% zuwa 81.5%.
Oxalic acid da tartaric acid gyare-gyare suna da amfani ga adsorption na methanol, yayin da citric acid yana da tasirin hanawa. Koyaya, J.Paul Chen et al. [35] gano cewa kunna carbon da aka gyara tare da citric acid na iya haɓaka adsorption na ions jan karfe. Lin Tang et al. [36] gyaggyara kunna carbon da aka kunna tare da formic acid, oxalic acid da aminosulfonic acid. Bayan gyare-gyare, an rage ƙayyadaddun yanki da ƙarar pore. Ƙungiyoyin ayyuka masu ɗauke da iskar oxygen kamar 0-HC-0, C-0 da S=0 an kafa su akan saman samfurin da aka gama, kuma tashoshi marasa daidaituwa da fararen lu'ulu'u sun bayyana. Matsakaicin adsorption na acetone da isopropanol shima ya karu sosai.
Fasahar gyara maganin alkaline
Wasu malaman kuma sun yi amfani da maganin alkaline don yin kunnawa na biyu akan carbon da aka kunna. Haɓaka carbon mai kunnawa na tushen kwal na gida tare da maganin Na0H na yawa daban-daban don sarrafa tsarin pore. Sakamakon ya nuna cewa ƙananan ƙwayar alkali yana taimakawa wajen haɓaka pore da fadadawa. An sami sakamako mafi kyau lokacin da yawan taro ya kasance 20%. Carbon da aka kunna yana da takamaiman yanki na musamman (681m2 · g-1) da ƙarar pore (0.5916cm3 · g-1). Lokacin da yawan taro na Na0H ya wuce 20%, an lalata tsarin pore na carbon da aka kunna kuma sigogin tsarin pore sun fara raguwa. Wannan shi ne saboda babban taro na maganin Na0H zai lalata kwarangwal na carbon kuma yawancin pores za su rushe.
Ana shirya babban aiki mai kunna carbon ta hanyar haɗakar da polymer. Abubuwan da suka riga sun kasance sune guduro mai furfural da barasa na furfuryl, kuma ethylene glycol shine wakili na samar da pore. An sarrafa tsarin pore ta hanyar daidaita abubuwan da ke cikin polymers guda uku, kuma an samo wani abu mai laushi tare da girman rami tsakanin 0.008 da 5 μm. Wasu malaman sun tabbatar da cewa fim din polyurethane-imide (PUI) na iya zama carbonized don samun fim din carbon, kuma ana iya sarrafa tsarin pore ta hanyar canza tsarin kwayoyin halitta na polyurethane (PU) prepolymer [41]. Lokacin da PUI ya yi zafi zuwa 200 ° C, PU da polyimide (PI) za a samar. Lokacin da zafin zafin zafin jiki ya tashi zuwa 400 ° C, PU pyrolysis yana haifar da iskar gas, wanda ya haifar da samuwar tsarin pore akan fim ɗin PI. Bayan carbonization, ana samun fim ɗin carbon. Bugu da ƙari, hanyar haɗakarwa ta polymer kuma na iya inganta wasu kaddarorin jiki da na injiniya na kayan zuwa wani ɗan lokaci
Fasahar kunna kunnawa catalytic
Fasahar kunna kunna katalytic shine haƙiƙanin haɗin hanyar kunna sinadari da hanyar kunna gas mai zafi. Gabaɗaya, ana ƙara abubuwan sinadarai a cikin albarkatun ƙasa azaman masu haɓakawa, kuma ana amfani da masu haɓakawa don taimakawa tsarin carbonization ko kunnawa don samun kayan carbon mai ƙyalli. Gabaɗaya magana, karafa gabaɗaya suna da tasirin catalytic, amma tasirin catalytic ya bambanta.
A haƙiƙa, yawanci babu takamaiman iyaka tsakanin ƙa'idodin kunna sinadarai da ƙa'idodin kunnawa mai ƙarfi na kayan porous. Wannan saboda duka hanyoyin suna ƙara reagents yayin aiwatar da carbonization da kunnawa. Takamaiman rawar waɗannan reagents yana ƙayyade ko hanyar ta kasance cikin nau'in kunnawa na catalytic.
Tsarin kayan carbon mai ƙyalƙyali da kansa, kayan aikin jiki da na sinadarai na mai kara kuzari, yanayin halayen kuzari da kuma hanyar ɗorawa mai ƙara kuzari na iya samun tasiri daban-daban na tasirin ƙa'ida. Yin amfani da gawayin bituminous azaman albarkatun ƙasa, Mn(N03)2 da Cu(N03)2 azaman masu haɓakawa na iya shirya kayan da ba su da ƙarfi waɗanda ke ɗauke da ƙarfe oxides. Adadin da ya dace na ƙarfe oxides zai iya inganta porosity da ƙarar pore, amma tasirin tasirin ƙarfe daban-daban ya ɗan bambanta. Cu (N03) 2 na iya inganta ci gaban pores a cikin kewayon 1.5 ~ 2.0nm. Bugu da kari, karfe oxides da inorganic salts kunshe a cikin albarkatun kasa toka suma za su taka rawar gani a cikin kunnawa tsari. Xie Qiang et al. [42] sun yi imanin cewa halayen kunnawa na abubuwa kamar calcium da baƙin ƙarfe a cikin kwayoyin halitta na iya inganta ci gaban pores. Lokacin da abun ciki na waɗannan abubuwa biyu ya yi yawa, adadin matsakaici da manyan pores a cikin samfurin yana ƙaruwa sosai.
Kammalawa
Ko da yake kunna carbon, kamar yadda mafi yadu amfani da kore porous carbon abu, ya taka muhimmiyar rawa a cikin masana'antu da kuma rayuwa, shi har yanzu yana da babban damar inganta albarkatun kasa fadada, farashin ragewa, ingancin inganta, makamashi inganta, rayuwa tsawo da kuma ƙarfi inganta. . Nemo high quality-da arha kunna carbon raw kayan, tasowa tsabta da ingantaccen kunna carbon samar da fasaha, da kuma ingantawa da kuma tsara pore tsarin na kunna carbon bisa daban-daban aikace-aikace filayen zai zama wani muhimmin al'amari ga inganta ingancin kunna carbon kayayyakin da kuma inganta. da high quality-ci gaba da kunna carbon masana'antu.
Lokacin aikawa: Agusta-27-2024