Ka Moolelo Noiʻi
Ma ke ʻano he kumuwaiwai kūlohelohe, nui a hiki ke hoʻohou hou ʻia, loaʻa i ka cellulose nā pilikia nui i nā noi hana ma muli o kona mau waiwai hoʻoheheʻe ʻole a me ka palena o ka solubility. ʻO ke kiʻekiʻe o ka crystallinity a me nā pilina hydrogen kiʻekiʻe i loko o ke ʻano cellulose e hoʻohaʻahaʻa ia akā ʻaʻole e hoʻoheheʻe ʻia i ka wā o ke kaʻina hana, a ʻaʻole hiki ke hoʻoheheʻe ʻia i ka wai a me ka hapa nui o nā mea hoʻoheheʻe organik. Hoʻopuka ʻia kā lākou mau derivatives e ka esterification a me ka etherification o nā hui hydroxyl ma nā ʻāpana anhydroglucose i loko o ke kaulahao polymer, a e hōʻike i kekahi mau waiwai like ʻole i hoʻohālikelike ʻia me ka cellulose kūlohelohe. Hiki i ka hopena etherification o ka cellulose ke hoʻopuka i nā ethers cellulose wai-soluble he nui, e like me ka 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 wai-soluble ke hana i nā polymers hydrogen-bonded me nā polycarboxylic acids a me polyphenols.
ʻO ka ʻākoakoa papa-ma-papa (LBL) kahi ʻano hana kūpono no ka hoʻomākaukau ʻana i nā kiʻiʻoniʻoni lahilahi composite polymer. ʻO ka mea ma lalo nei e wehewehe nui ana i ka ʻākoakoa LBL o ʻekolu mau CE like ʻole o HEC, MC a me HPC me PAA, e hoʻohālikelike ana i kā lākou ʻano ʻākoakoa, a kālailai i ka mana o nā mea pani ma ka ʻākoakoa LBL. E noiʻi i ka hopena o ka pH ma ka mānoanoa o ka kiʻiʻoniʻoni, a me nā ʻokoʻa like ʻole o ka pH ma ka hoʻokumu ʻana a me ka hoʻoheheʻe ʻana o ka kiʻiʻoniʻoni, a hoʻomohala i nā waiwai omo wai o CE/PAA.
Nā Mea Hoʻokolohua:
ʻO ka waikawa Polyacrylic (PAA, Mw = 450,000). ʻO ka mānoanoa o ka hopena wai 2wt.% o ka hydroxyethylcellulose (HEC) he 300 mPa·s, a ʻo ke kekelē o ka pani ʻana he 2.5. ʻO Methylcellulose (MC, kahi hopena wai 2wt.% me ka mānoanoa o 400 mPa·s a me ke kekelē o ka pani ʻana o 1.8). ʻO Hydroxypropyl cellulose (HPC, kahi hopena wai 2wt.% me ka mānoanoa o 400 mPa·s a me ke kekelē o ka pani ʻana o 2.5).
Hoʻomākaukau kiʻiʻoniʻoni:
Hoʻomākaukau ʻia e ka hui ʻana o ka papa kristal wai ma luna o ka silicon ma 25°C. ʻO ke ʻano hana o ka matrix slide penei: e hoʻomohu i loko o ka hopena waikawa (H2SO4/H2O2, 7/3Vol/VOL) no 30min, a laila holoi me ka wai deionized i nā manawa he nui a hiki i ka pH ke lilo i neutral, a maloʻo hope me ka naikokene maʻemaʻe. Hana ʻia ka hui ʻana o LBL me ka hoʻohana ʻana i nā mīkini hana. Ua hoʻomohu ʻia ke substrate i loko o ka hopena CE (0.2 mg/mL) a me ka hopena PAA (0.2 mg/mL), ua hoʻomohu ʻia kēlā me kēia hopena no 4 min. ʻEkolu mau hoʻomohu holoi o 1 min i loko o ka wai deionized i hana ʻia ma waena o kēlā me kēia hoʻomohu hoʻonā e wehe i ka polymer i hoʻopaʻa ʻole ʻia. Ua hoʻoponopono ʻia nā waiwai pH o ka hopena hui a me ka hopena holoi i ka pH 2.0. Ua hōʻailona ʻia nā kiʻiʻoniʻoni i hoʻomākaukau ʻia ʻo (CE/PAA)n, kahi e hōʻike ai ʻo n i ke kaʻina hana hui. Ua hoʻomākaukau nui ʻia (HEC/PAA)40, (MC/PAA)30 a me (HPC/PAA)30.
ʻAno Kiʻiʻoniʻoni:
Ua hoʻopaʻa ʻia a kālailai ʻia nā spectra reflectance kokoke i ka maʻamau me NanoCalc-XR Ocean Optics, a ua ana ʻia ka mānoanoa o nā kiʻiʻoniʻoni i waiho ʻia ma luna o ka silicon. Me kahi substrate silicon hakahaka ma ke ʻano he kua, ua hōʻiliʻili ʻia ka spectrum FT-IR o ka kiʻiʻoniʻoni lahilahi ma luna o ka substrate silicon ma kahi spectrometer infrared Nicolet 8700.
Nā pilina pilina hydrogen ma waena o PAA a me CE:
ʻO ka hoʻākoakoa ʻana o HEC, MC a me HPC me PAA i loko o nā kiʻiʻoniʻoni LBL. Hōʻike ʻia nā 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 i nā spectra IR o HEC/PAA, MC/PAA a me HPC/PAA. Hiki i ka spectroscopy FT-IR ke kālailai i ka paʻakikī o ka pilina hydrogen ma waena o PAA a me CES ma ka nānā ʻana i ka neʻe ʻana o nā hui absorption hiʻohiʻona. ʻO ka pilina hydrogen ma waena o CES a me PAA e hana nui ʻia ma waena o ka oxygen hydroxyl o CES a me ka hui COOH o PAA. Ma hope o ka hoʻokumu ʻia ʻana o ka pilina hydrogen, neʻe ka ʻulaʻula piko e hohola ana i ke kuhikuhi alapine haʻahaʻa.
Ua ʻike ʻia kahi piko o 1710 cm-1 no ka pauka PAA maʻemaʻe. I ka wā i hoʻākoakoa ʻia ai ka polyacrylamide i loko o nā kiʻiʻoniʻoni me nā CE like ʻole, ua loaʻa nā piko o nā kiʻiʻoniʻoni HEC/PAA, MC/PAA a me MPC/PAA ma 1718 cm-1, 1720 cm-1 a me 1724 cm-1, kēlā me kēia. Ke hoʻohālikelike ʻia me ka pauka PAA maʻemaʻe, ua neʻe nā lōʻihi piko o nā kiʻiʻoniʻoni HPC/PAA, MC/PAA a me HEC/PAA e 14, 10 a me 8 cm−1, kēlā me kēia. ʻO ka pilina hydrogen ma waena o ka ether oxygen a me COOH e hoʻopau i ka pilina hydrogen ma waena o nā hui COOH. ʻO ka nui o nā pilina hydrogen i hoʻokumu ʻia ma waena o PAA a me CE, ʻo ka nui o ka neʻe ʻana o ka piko o CE/PAA ma nā spectra IR. Loaʻa iā HPC ke kiʻekiʻe kiʻekiʻe o ka paʻakikī o ka pilina hydrogen, aia ʻo PAA a me MC ma waena, a ʻo HEC ka haʻahaʻa loa.
Ke ʻano ulu o nā kiʻiʻoniʻoni hui pū ʻia o PAA a me CE:
Ua noiʻi ʻia ke ʻano hana ʻoniʻoni o PAA a me CE i ka wā o ka ʻākoakoa ʻana o LBL me ka hoʻohana ʻana iā QCM a me ka interferometry spectral. He kūpono ʻo QCM no ka nānā ʻana i ka ulu ʻana o ke kiʻiʻoniʻoni ma kahi i nā pōʻaiapuni ʻākoakoa mua. He kūpono nā interferometers spectral no nā kiʻiʻoniʻoni i ulu ʻia ma luna o 10 mau pōʻaiapuni.
Ua hōʻike ke kiʻiʻoniʻoni HEC/PAA i kahi ulu linear ma o ke kaʻina hana hōʻuluʻulu LBL, ʻoiai ua hōʻike nā kiʻiʻoniʻoni MC/PAA a me HPC/PAA i kahi ulu exponential i nā pae mua o ka hōʻuluʻulu ʻana a laila ua hoʻololi ʻia i ulu linear. Ma ka ʻāpana ulu linear, ʻo ke kiʻekiʻe o ke kekelē o ka complexation, ʻo ka nui o ka ulu ʻana o ka mānoanoa i kēlā me kēia pōʻaiapuni hōʻuluʻulu.
Ka hopena o ka pH o ka hopena ma ka ulu ʻana o ka ʻili:
Hoʻopilikia ka waiwai pH o ka hopena i ka ulu ʻana o ka ʻili hui polymer i hoʻopaʻa ʻia i ka hydrogen. Ma ke ʻano he polyelectrolyte nāwaliwali, e hoʻohuihui ʻia ʻo PAA a hoʻopiʻi maikaʻi ʻole ʻia i ka piʻi ʻana o ka pH o ka hopena, a laila e pale ana i ka hui ʻana o ka hydrogen bond. I ka hiki ʻana o ke kekelē o ka ionization o PAA i kekahi pae, ʻaʻole hiki iā PAA ke hōʻuluʻulu i loko o kahi ʻili me nā mea hoʻokipa hydrogen bond ma LBL.
Ua emi ka mānoanoa o ke kiʻiʻoniʻoni me ka piʻi ʻana o ka pH o ka hopena, a ua emi koke ka mānoanoa o ke kiʻiʻoniʻoni ma ka pH2.5 HPC/PAA a me ka pH3.0-3.5 HPC/PAA. ʻO ke kiko koʻikoʻi o HPC/PAA ma kahi o pH 3.5, ʻoiai ʻo HEC/PAA ma kahi o 3.0. ʻO ke ʻano kēia, i ka wā e ʻoi aku ai ka pH o ka hopena hui ma mua o 3.5, ʻaʻole hiki ke hoʻokumu ʻia ke kiʻiʻoniʻoni HPC/PAA, a i ka wā e ʻoi aku ai ka pH o ka hopena ma mua o 3.0, ʻaʻole hiki ke hoʻokumu ʻia ke kiʻiʻoniʻoni HEC/PAA. Ma muli o ke kiʻekiʻe o ka paʻa hydrogen o ka membrane HPC/PAA, ʻoi aku ka kiʻekiʻe o ka waiwai pH koʻikoʻi o ka membrane HPC/PAA ma mua o ka membrane HEC/PAA. I ka hopena paʻakai ʻole, ʻo nā waiwai pH koʻikoʻi o nā paʻakikī i hoʻokumu ʻia e HEC/PAA, MC/PAA a me HPC/PAA ma kahi o 2.9, 3.2 a me 3.7, kēlā me kēia. ʻOi aku ke kiʻekiʻe o ka pH koʻikoʻi o HPC/PAA ma mua o ko HEC/PAA, kahi e kūlike me ko ka membrane LBL.
Ka hana omo wai o ka membrane CE/PAA:
Waiwai ʻo CES i nā hui hydroxyl no laila he maikaʻi ka omo ʻana o ka wai a me ka paʻa ʻana o ka wai. Ma ka lawe ʻana i ka membrane HEC/PAA ma ke ʻano he laʻana, ua aʻo ʻia ka hiki ke adsorption o ka membrane CE/PAA i hoʻopaʻa ʻia i ka hydrogen i ka wai i loko o ke kaiapuni. Hōʻike ʻia e ka interferometry spectral, piʻi ka mānoanoa o ka ʻili i ka wā e omo ai ka ʻili i ka wai. Ua waiho ʻia i loko o kahi kaiapuni me ka haʻahaʻa hiki ke hoʻololi ʻia ma 25°C no 24 mau hola e hoʻokō ai i ke kaulike omo wai. Ua hoʻomaloʻo ʻia nā ʻili i loko o ka umu vacuum (40°C) no 24 hola e hoʻopau loa i ka makū.
I ka piʻi ʻana o ka makū, mānoanoa ka ʻili. Ma kahi haʻahaʻa o ka makū o 30%-50%, lohi iki ka ulu ʻana o ka mānoanoa. Ke ʻoi aku ka makū ma mua o 50%, ulu wikiwiki ka mānoanoa. Ke hoʻohālikelike ʻia me ka membrane PVPON/PAA i hoʻopaʻa ʻia me ka hydrogen, hiki i ka membrane HEC/PAA ke omo i ka wai hou aku mai ke kaiapuni. Ma lalo o ke kūlana o ka makū pili o 70% (25°C), ʻo ka laulā mānoanoa o ka ʻili PVPON/PAA ma kahi o 4%, ʻoiai ʻo ka ʻili HEC/PAA he kiʻekiʻe e like me 18%. Ua hōʻike nā hopena ʻoiai ua komo kekahi mau hui OH i loko o ka ʻōnaehana HEC/PAA i ka hoʻokumu ʻana o nā pilina hydrogen, aia nō ka nui o nā hui OH e launa pū ana me ka wai i ke kaiapuni. No laila, he maikaʻi nā waiwai omo wai o ka ʻōnaehana HEC/PAA.
i ka hopena
(1) ʻO ka ʻōnaehana HPC/PAA me ke kekelē hoʻopaʻa hydrogen kiʻekiʻe loa o CE a me PAA ka mea ulu wikiwiki loa ma waena o lākou, aia ʻo MC/PAA ma waena, a ʻo HEC/PAA ka haʻahaʻa loa.
(2) Ua hōʻike ke kiʻiʻoniʻoni HEC/PAA i kahi ʻano ulu linear ma o ke kaʻina hana hoʻomākaukau, ʻoiai ʻo nā kiʻiʻoniʻoni ʻelua ʻē aʻe ʻo MC/PAA a me HPC/PAA i hōʻike i kahi ulu exponential i nā pōʻaiapuni mua, a laila ua hoʻololi ʻia i kahi ʻano ulu linear.
(3) ʻO ka ulu ʻana o ka ʻili CE/PAA he hilinaʻi nui ia i ka pH o ka hopena. Ke kiʻekiʻe aʻe ka pH o ka hopena ma mua o kona kiko koʻikoʻi, ʻaʻole hiki iā PAA a me CE ke hoʻākoakoa i loko o kahi ʻili. Ua hiki ke hoʻoheheʻe ʻia ka membrane CE/PAA i hoʻākoakoa ʻia i loko o nā hopena pH kiʻekiʻe.
(4) ʻOiai ua waiwai ka ʻili CE/PAA i ka OH a me COOH, ʻo ka mālama ʻana i ka wela e hoʻopili ai iā ia. 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 ʻili CE/PAA ka mana adsorption maikaʻi no ka wai i ke kaiapuni.
Ka manawa hoʻouna: Pepeluali-18-2023