Ka Huli Huli
Ma ke ʻano he kumu kūlohelohe, nui a hiki ke hoʻololi hou ʻia, hālāwai ʻo cellulose i nā luʻi nui i nā noi kūpono ma muli o kāna mau mea hoʻoheheʻe ʻole a kaupalena ʻia. ʻO ka crystallinity kiʻekiʻe a me nā paʻa hydrogen kiʻekiʻe i loko o ka hale cellulose e hoʻohaʻahaʻa akā ʻaʻole hoʻoheheʻe i ka wā o ke kaʻina hana, a hiki ʻole ke hoʻoheheʻe ʻia i ka wai a me ka hapa nui o nā mea hoʻoheheʻe organik. Hoʻokumu ʻia kā lākou derivatives e ka esterification a me ka etherification o nā pūʻulu hydroxyl ma nā ʻāpana anhydroglucose i ke kaulahao polymer, a e hōʻike i kekahi mau waiwai like ʻole i hoʻohālikelike ʻia me ka cellulose maoli. Hiki i ka hopena etherification o cellulose ke hoʻoulu i ka wai-soluble cellulose ethers, e like me methyl cellulose (MC), hydroxyethyl cellulose (HEC) a me hydroxypropyl cellulose (HPC), i hoʻohana nui ʻia i ka meaʻai, nā mea hoʻonaninani, i nā lāʻau lapaʻau a me nā lāʻau lapaʻau. Hiki i ka CE hiki ke hoʻoheheʻe i ka wai i nā polymers i hoʻopaʻa ʻia i ka hydrogen me nā waikawa polycarboxylic a me nā polyphenols.
He ala maikaʻi ka Layer-by-layer assembly (LBL) no ka hoʻomākaukau ʻana i nā kiʻi ʻoniʻoni lahilahi polymer composite. ʻO ka mea ma lalo nei ka wehewehe nui ʻana i ka hui LBL o ʻekolu CE like ʻole o HEC, MC a me HPC me PAA, hoʻohālikelike i kā lākou ʻano hui, a nānā i ka mana o nā mea pani i ka hui LBL. E noiʻi i ka hopena o ka pH ma ka mānoanoa kiʻiʻoniʻoni, a me nā ʻokoʻa like ʻole o ka pH i ka hoʻokumu ʻana a me ka hoʻoheheʻe ʻana, a hoʻomohala i nā waiwai absorption wai o CE/PAA.
Nā mea hoʻokolohua:
Polyacrylic acid (PAA, Mw = 450,000). ʻO ka viscosity o 2wt.% aqueous solution o hydroxyethylcellulose (HEC) he 300 mPa·s, a ʻo ke degere o ka hoʻololi ʻana he 2.5. Methylcellulose (MC, he 2wt.% aqueous solution me ka viscosity o 400 mPa·s a me kahi degere o ka hoʻololi o 1.8). Hydroxypropyl cellulose (HPC, he 2wt.% aqueous solution me ka viscosity o 400 mPa·s a me ke kēkelē o ka hoʻololi o 2.5).
Hoʻomākaukau kiʻiʻoniʻoni:
Hoʻomākaukau ʻia e ka hui ʻana o ka wai aniani ma luna o ke silika ma 25°C. ʻO ke ʻano o ka mālama ʻana i ka matrix paheʻe penei: e hoʻomoʻa i loko o ka solution acidic (H2SO4/H2O2, 7/3Vol/VOL) no 30min, a laila holoi me ka wai deionized i nā manawa he nui a lilo ka pH i kū ʻole, a maloʻo me ka nitrogen maʻemaʻe. Hana ʻia ka hui LBL me ka hoʻohana ʻana i nā mīkini ʻakomi. Hoʻopili ʻia ka substrate i loko o ka hopena CE (0.2 mg / mL) a me ka solution PAA (0.2 mg / mL), ua hoʻonā ʻia kēlā me kēia hopena no 4 min. ʻEkolu hoʻomaʻemaʻe ʻana o 1 min i kēlā me kēia i loko o ka wai deionized i hana ʻia ma waena o kēlā me kēia hoʻonā wai e wehe i ka polymer i hoʻopaʻa ʻia. Ua hoʻoponopono ʻia nā koina pH o ka ʻaha hui a me ka wai holoi i ka pH 2.0. Hōʻike ʻia nā kiʻiʻoniʻoni i hoʻomākaukau ʻia e like me (CE/PAA)n, kahi n e hōʻike ai i ka pōʻaiapuni hui. (HEC/PAA)40, (MC/PAA)30 a me (HPC/PAA)30 i hoomakaukau nui ia.
Hōʻike kiʻiʻoniʻoni:
Ua hoʻopaʻa ʻia a nānā ʻia me NanoCalc-XR Ocean Optics, a ua ana ʻia ka mānoanoa o nā kiʻiʻoniʻoni i waiho ʻia ma ke silika. Me kahi pani kīlika hakahaka e like me ke kāʻei kua, ua hōʻiliʻili ʻia ka spectrum FT-IR o ke kiʻiʻoniʻoni lahilahi ma ka substrate silicon ma kahi spectrometer infrared Nicolet 8700.
Nā pilina paʻa hydrogen ma waena o PAA a me CE:
ʻO ka hui ʻana o HEC, MC a me HPC me PAA i loko o nā kiʻiʻoniʻoni LBL. Hōʻike ʻia ka spectra infrared o HEC/PAA, MC/PAA a me HPC/PAA ma ke kiʻi. Hiki ke ʻike maopopo ʻia nā hōʻailona IR ikaika o PAA a me CES ma ka spectra IR o HEC/PAA, MC/PAA a me HPC/PAA. Hiki i ka FT-IR spectroscopy ke kālailai i ka paʻakikī paʻa hydrogen ma waena o PAA a me CES ma o ka nānā ʻana i ka neʻe ʻana o nā kaula absorption. ʻO ka hoʻopaʻa hydrogen ma waena o CES a me PAA ka mea nui ma waena o ka oxygen hydroxyl o CES a me ka hui COOH o PAA. Ma hope o ka hoʻokumu ʻia ʻana o ka paʻa hydrogen, e neʻe ka ʻulaʻula kiʻekiʻe kiʻekiʻe i ke alapine haʻahaʻa.
Ua ʻike ʻia kahi kiʻekiʻe o 1710 cm-1 no ka pauka PAA maʻemaʻe. I ka hui ʻana o ka polyacrylamide i nā kiʻiʻoniʻoni me nā CE ʻokoʻa, aia nā piko o nā kiʻi ʻoniʻoni HEC/PAA, MC/PAA a me MPC/PAA ma 1718 cm-1, 1720 cm-1 a me 1724 cm-1. Hoʻohālikelike ʻia me ka pauka PAA maʻemaʻe, ua hoʻololi ʻia nā kiʻi ʻoniʻoni HPC/PAA, MC/PAA a me HEC/PAA e 14, 10 a me 8 cm−1. ʻO ka paʻa hydrogen ma waena o ka oxygen eter a me COOH e hoʻopau i ka pilina hydrogen ma waena o nā hui COOH. ʻOi aku ka nui o nā paʻa hydrogen i hana ʻia ma waena o PAA a me CE, ʻoi aku ka nui o ka hoʻololi kiʻekiʻe o CE/PAA ma IR spectra. Loaʻa iā HPC ka pae kiʻekiʻe o ka paʻa paʻa hydrogen, ʻo PAA a me MC ma waena, a ʻo HEC ka haʻahaʻa.
ʻO ka ulu ʻana o nā kiʻi ʻoniʻoni ʻoniʻoni o PAA a me CEs:
Ua noiʻi ʻia ke ʻano hana kiʻiʻoniʻoni o PAA a me CE i ka wā o ka hui LBL me ka hoʻohana ʻana i QCM a me spectral interferometry. Maikaʻi ʻo QCM no ka nānā ʻana i ka ulu ʻana o ke kiʻiʻoniʻoni ma ke kahua i ka wā o nā pōʻai hui mua. Kūpono nā interferometers spectral no nā kiʻiʻoniʻoni i ulu ma luna o 10 mau pōʻai.
Ua hōʻike ka kiʻi ʻoniʻoni HEC/PAA i ka ulu laina i loko o ke kaʻina hui LBL, ʻoiai nā kiʻi ʻoniʻoni MC/PAA a me HPC/PAA i hōʻike i ka ulu nui i ka wā mua o ka hui ʻana a laila hoʻololi ʻia i ulu laina. Ma ka ʻāpana ulu laina, ʻoi aku ka kiʻekiʻe o ke kiʻekiʻe o ka paʻakikī, ʻoi aku ka nui o ka ulu ʻana o ka mānoanoa i kēlā me kēia pōʻai hui.
Ka hopena o ka pH solution ma ka ulu kiʻiʻoniʻoni:
Hoʻopili ka pH waiwai o ka hopena i ka ulu ʻana o ke kiʻi ʻoniʻoni polymer i hoʻopaʻa ʻia i ka hydrogen. Ma ke ʻano he polyelectrolyte nāwaliwali, e hoʻopaʻa ʻia ʻo PAA a hoʻopiʻi maikaʻi ʻole ʻia i ka piʻi ʻana o ka pH o ka hopena, a laila ke keʻakeʻa nei i ka hui paʻa hydrogen. I ka hiki ʻana o ke degere o ka ionization o PAA i kahi pae, ʻaʻole hiki iā PAA ke hoʻohui i kahi kiʻiʻoniʻoni me nā mea hoʻopaʻa hydrogen i LBL.
Ua emi ka mānoanoa kiʻiʻoniʻoni me ka piʻi ʻana o ka pH solution, a ua emi koke ka mānoanoa kiʻiʻoniʻoni ma pH2.5 HPC/PAA a me pH3.0-3.5 HPC/PAA. ʻO ka helu koʻikoʻi o HPC/PAA e pili ana i ka pH 3.5, aʻo ko HEC/PAA ma kahi o 3.0. ʻO ia ke ʻano o ka pH o ka hopena hui ma mua o 3.5, ʻaʻole hiki ke hoʻokumu ʻia ke kiʻi HPC/PAA, a ke kiʻekiʻe ka pH o ka hopena ma mua o 3.0, ʻaʻole hiki ke hoʻokumu ʻia ke kiʻi HEC/PAA. Ma muli o ke kiʻekiʻe o ka paʻa paʻa hydrogen o ka membrane HPC/PAA, ʻoi aku ka kiʻekiʻe o ka pH koʻikoʻi o ka membrane HPC/PAA ma mua o ka membrane HEC/PAA. I loko o ka paʻakai paʻakai, ʻo nā koʻikoʻi pH koʻikoʻi o nā paʻakikī i hana ʻia e HEC/PAA, MC/PAA a me HPC/PAA ma kahi o 2.9, 3.2 a me 3.7. ʻOi aku ka kiʻekiʻe o ka pH koʻikoʻi o ka HPC/PAA ma mua o ka HEC/PAA, i kūlike me ka membrane LBL.
ʻO ka hana hoʻoheheʻe wai o ka membrane CE / PAA:
He waiwai ʻo CES i nā hui hydroxyl i loaʻa iā ia ka hoʻoheheʻe wai maikaʻi a me ka paʻa wai. ʻO ka lawe ʻana i ka membrane HEC/PAA ma ke ʻano he laʻana, ua aʻo ʻia ka mana adsorption o ka membrane CE/PAA i hoʻopaʻa ʻia i ka hydrogen i ka wai i ke kaiapuni. Hōʻike ʻia e ka spectral interferometry, piʻi ka mānoanoa o ke kiʻiʻoniʻoni i ka wā e komo ai ke kiʻi i ka wai. Hoʻokomo ʻia i loko o kahi kaiapuni me ka haʻahaʻa hiki ke hoʻololi ʻia ma 25 ° C no 24 mau hola e hoʻokō ai i ka equilibrium absorption wai. Ua hoʻomaloʻo ʻia nā kiʻiʻoniʻoni i loko o kahi umu ʻūhā (40 °C) no 24 mau hola e hoʻopau loa i ka makū.
Ke piʻi aʻe ka haʻahaʻa, mānoanoa ke kiʻiʻoniʻoni. Ma kahi haʻahaʻa haʻahaʻa o 30% -50%, ua lohi ka ulu ʻana o ka mānoanoa. Ke piʻi ka haʻahaʻa ma mua o 50%, ulu wikiwiki ka mānoanoa. Ke hoʻohālikelikeʻia me ka PVPON / PAA membrane i hoʻopaʻaʻia i ka hydrogen, hiki i ka HEC / PAA membrane ke hoʻonui i ka wai mai ke kaiapuni. Ma lalo o ke kūlana o ka haʻahaʻa haʻahaʻa o 70% (25 ° C), ka mānoanoa o ka PVPON / PAA kiʻi ʻoniʻoni ma kahi o 4%, ʻoiai ʻo ka kiʻi HEC / PAA he kiʻekiʻe ma kahi o 18%. Ua hōʻike nā hualoaʻa, ʻoiai ua komo kekahi mau pūʻulu OH i loko o ka ʻōnaehana HEC/PAA i ka hoʻokumu ʻana i nā paʻa hydrogen, aia nō ka nui o nā pūʻulu OH e launa pū ana me ka wai i ke kaiapuni. No laila, loaʻa i ka ʻōnaehana HEC/PAA nā waiwai hoʻoheheʻe wai maikaʻi.
i ka hopena
(1) ʻO ka ʻōnaehana HPC/PAA me ka degere hoʻopaʻa hydrogen kiʻekiʻe loa o CE a me PAA ʻoi aku ka wikiwiki o ka ulu ʻana ma waena o lākou, ʻo MC/PAA ma waena, a ʻo HEC/PAA ka haʻahaʻa.
(2) Ua hōʻike ke kiʻi ʻoniʻoni HEC/PAA i ke ʻano ulu laina i loko o ke kaʻina hana hoʻomākaukau, ʻoiai ʻo nā kiʻi ʻelua ʻelua ʻo MC/PAA a me HPC/PAA i hōʻike i kahi ulu exponential i nā pōkole mua, a laila hoʻololi ʻia i ke ʻano ulu laina.
(3) ʻO ka ulu ʻana o ke kiʻi ʻoniʻoni CE / PAA he hilinaʻi ikaika i ka pH solution. Ke kiʻekiʻe ka pH o ka hopena ma mua o kona wahi koʻikoʻi, ʻaʻole hiki iā PAA a me CE ke hui pū i kahi kiʻiʻoniʻoni. Hiki ke hoʻoheheʻe ʻia ka membrane CE/PAA i hui ʻia i nā hopena pH kiʻekiʻe.
(4) Ma muli o ka waiwai o ka kiʻi ʻoniʻoni CE/PAA i ka OH a me COOH, ʻo ka hoʻomaʻamaʻa ʻana i ka wela e hoʻopili ai. He kūpaʻa maikaʻi ka membrane CE/PAA i hoʻopili ʻia a ʻaʻole hiki ke hoʻoheheʻe ʻia i nā hopena pH kiʻekiʻe.
(5) Loaʻa i ka kiʻi ʻoniʻoni CE / PAA ka mana adsorption maikaʻi no ka wai i loko o ke kaiapuni.
Ka manawa hoʻouna: Feb-18-2023