Ua pili ka HEC i ka pH?

ʻO ka Hydroxyethylcellulose (HEC) he polymer hiki ke hoʻohana ʻia i ka ʻoihana a me ka noiʻi ʻepekema. Hoʻohana nui ʻia ʻo ia e like me kahi mānoanoa, mea hana kiʻiʻoniʻoni, adhesive, emulsifier a me stabilizer.

Nā waiwai kumu o HEC
ʻO HEC he polymer wai-soluble non-ionic, he derivative hydroxyethylated i loaʻa mai ka cellulose ma o ka hopena ethylation. Ma muli o kona ʻano non-ionic, ʻaʻole i hoʻololi nui ʻia ke ʻano o HEC i ka hopena e ka pH o ka hopena. ʻO ka ʻokoʻa, ʻoi aku ka maʻalahi o ka nui o nā polymers ionic (e like me ka sodium polyacrylate a i ʻole carbomers) i ka pH no ka mea e loli ana ko lākou mokuʻāina me nā loli i ka pH, e pili ana i ko lākou solubility a me ka mānoanoa. hana a me nā waiwai ʻē aʻe.

Hana o HEC ma nā koina pH like ʻole
He kūpaʻa maikaʻi ka HEC ma lalo o nā kūlana acidic a alkaline. ʻO ka kikoʻī, hiki i ka HEC ke mālama i kona viscosity a me nā waiwai mānoanoa ma luna o kahi ākea o nā kaiapuni pH. Hōʻike ka noiʻi i ka paʻa o ka viscosity a me ka mānoanoa o HEC i loko o ka pae pH o 3 a hiki i 12. ʻO kēia ka HEC i mea mānoanoa loa a me ka stabilizer i nā noi ʻoihana he nui a hiki ke hoʻohana ʻia ma lalo o nā kūlana pH like ʻole.

Eia nō naʻe, hiki ke hoʻopili ʻia ka paʻa o HEC i nā koina pH koʻikoʻi (e like me ka pH ma lalo o 2 a ma luna o 13). Ma lalo o kēia mau kūlana, hiki i nā kaulahao mole o HEC ke hana i ka hydrolysis a i ʻole ka hoʻohaʻahaʻa ʻana, e hoʻemi ana i kona viscosity a i ʻole nā ​​loli i kāna mau waiwai. No laila, ʻo ka hoʻohana ʻana o HEC ma lalo o kēia mau kūlana koʻikoʻi e pono ai ka nānā kūikawā i kona kūpaʻa.

Noonoo noi
Ma nā noi kūpono, pili pū ka pH sensitivity o HEC i nā mea ʻē aʻe, e like me ka mahana, ka ikaika ionic, a me ka polarity o ka solvent. I kekahi mau noi, ʻoiai he liʻiliʻi ka hopena o ka hoʻololi pH i ka HEC, hiki i nā mea kaiapuni ke hoʻonui i kēia hopena. No ka laʻana, ma lalo o nā kūlana wela kiʻekiʻe, hiki i nā kaulahao molecular HEC ke hydrolyze wikiwiki, no laila e ʻoi aku ka hopena o kāna hana.

Eia kekahi, i kekahi mau mea hoʻohālikelike, e like me nā emulsions, gels and coatings, hoʻohana pinepine ʻia ʻo HEC me nā mea ʻē aʻe (e like me nā surfactants, salts a i ʻole nā ​​mea hoʻoponopono acid-base). I kēia manawa, ʻoiai ʻaʻole pili ʻo HEC i ka pH ponoʻī, hiki i kēia mau mea ʻē aʻe ke hoʻopilikia i ka hana o HEC ma o ka hoʻololi ʻana i ka pH. No ka laʻana, hoʻololi ke kūlana hoʻopiʻi o kekahi mau surfactants i nā koina pH like ʻole, hiki ke hoʻopili i ka pilina ma waena o HEC a me nā surfactants, a laila hoʻololi i nā waiwai rheological o ka hopena.

ʻO HEC kahi polymer non-ionic i pili ʻole i ka pH a loaʻa ka hana maikaʻi a me ke kūpaʻa ma luna o kahi ākea pH ākea. Hoʻohana nui kēia i nā noi he nui, ʻoi aku ka nui o ka hana paʻa o nā mānoanoa a me nā mea hana kiʻiʻoniʻoni e koi ʻia. Eia nō naʻe, he mea nui e noʻonoʻo i ka hopena o ka paʻa a me ka hana o ka HEC ma lalo o nā kūlana pH koʻikoʻi a i ʻole ke hoʻohana ʻia me nā mea ʻē aʻe pH-sensitive. No nā pilikia koʻikoʻi pH i nā noi kikoʻī, ʻōlelo ʻia e hana i ka hoʻāʻo a me ka hōʻoia kūpono ma mua o ka hoʻohana maoli ʻana e hōʻoia i hiki i ka HEC ke hana maikaʻi ma lalo o nā kūlana i manaʻo ʻia.