3-Bromopropyldialkylamine hydrogen bromide of different alkyl groups could be synthesized from 3-aminopropanol by reacting first with alkyl halide, and then with $PBr_3$. Other substituted dialkylamine salts including hexyl, undodecyl, ethoxyethyl, ethoxyethoxyethyl derivatives were also prepared according to the similar method. Most of the amine salts mentioned above could be dispered by forming vesicles in water by sonication or vortex mixing, but failed to polymerize. Polymeric vesicle dispersion by ultra-sonic irradiation were obtained only in the case of 3-bromopropyldialkyl-amine salts even though the molecular weights were low. During the dispersion process of 3-bromopropyl-didodecylamine hydrogen bromide, coded as BPDH, dispersed in water by ultra-sonic irradiation, oligomerization of BPDH also took place in vesicle form. The polymerization was probably facilitated by amphiphilic aggregation. The pH of thus obtained dispersion was then adjusted to 10 with 1.0 M NaOH. And the resulting dispersion was again sonicated for polymerization through quaternization. The pH of the polymeric dispersion thus obtained was 8.2-8.6 indicating that the quaternization of amines had taken place.
Electron micrographs confirmed the presence of closed vesicles of polymeric BPDH having diameters ranging between 300 and 1400 Å. The vesicles are mostly multi-lamellae of bilayers of ca. 50Å width. Polymeric BPDH gave well developed multi-walled vesicles compared with monomeric analogue 3-bromopropylmethyldidodecylammonium bromide (BDMA). Further evidence for closed vesicles comes from the entrapment of $[^{14}C]$ sucrose. The amount of $[^{14}C]$ sucrose entrapped into vesicles of polymeric BPDH were about 2%. It was also confirmed by electron micrographs that other amphiphiles formed vesicles. And chromatograms of GPC showed the lyophilized BPDH possess oligomeric structures. Lyophilized polymeric product was quite different in solubility compared with BPDH, being completely insoluble in most of solvents.
In order to evaluate the stability of vesicles, their response to the addition of ethanol was examined and the change in absorbance was observed. The turbidity (absorbance at 400 nm) of vesicles of polymeric BPDH remained almost constant up to 25% ethanol (V/V). In contrast, similar experiments conducted with vesicles derived from BDMA showed precipitation even at 5% ethanol. On standing at room temperature, the vesicle of BDMA remain stable for ca. 72 hours. However, the polymeric vesicles of BPDH were stable for at least several months.
이중알킬 양친매성염(BPDH, BPTH, BPHH)은 3-아미노프로판올과 할로알칸을 반응하여 3가 아민을 합성한후, $PBr_3$와 브롬산수용액의 반응에 의하여 합성하였다.
물속에서 양친매성염을 초음파 진동에 의하여 분산시키면 미세액포가 생성되며, 생성된 미세액포는 단량체가 아닌 올리고머 형태로 얻었다. 올리고머 미세액포에 1몰의 가성소다 용액으로 PH10으로 조절한후 다시 초음파 진동을 가하면, 고분자 미세액포가 생성되었다.
고분자 미세액포와 단량체 미세액포는 전자현미경 사진으로 구형의 미세액포가 생성된 것을 확인하였다. 미세액포가 이중층막으로 밀폐된 것을 확인하기 위하여 미세액포의 내부 수용액에 비이온 물질인 $[^{14}C]$ sucrose 의 포획 실험에서 미세액포의 형성전에 첨가된 총량의 2% 정도가 포획된 것을 확인하였다.
고분자 미세액포는 단량체 (BDMA)나 올리고머 미세액포보다 상온에서 안정성이 좋으며 몇달 동안 상태의 변화가 없으며 에탄올이 25% 첨가된 용액에서도 미세액포가 유지되었다.
