The objective of this study was to examine changes in the dissolution rate of sodium-alginate/polyacrylamide (SA/PAM) hydrogel according to water temperature and concentration of cross-linking agent N,N'-methylenebisacrylamide (MBAAm). Results confirmed that swelling and dissolution rates of the SA/PAM hydrogel were increased when the temperature of the water was increased or the amount of MBAAm was decreased. When water temperature was increased, ionic crosslinks became unstable and amide bonds were broken due to hydrolysis, causing the hydrogel to rapidly dissolve in the hot water. Also, after the amount of MBAAm was decreased, ionic crosslinks became dominant and SA/PAM hydrogel became more vulnerable to hot water. Here, we analyzed the dissolution rate of hydrogel following temperature and MBAAm density changes. We also developed a selectively dissolvable water-blocking hydrogel that could be stable in cold water and become dissolved quickly in hot water.

본 연구에서는 나트륨-알지네이트/폴리아크릴아마이드(SA/PAM) 하이드로겔의 온도 및 가교제로 작용하는 N,N′-메틸렌비스아크릴아마이드(MBAAm) 농도에 따른 수용 형태 및 시간 변화를 분석하였다. 실험 결과, 수온이 증가하거나 가교제 농도가 감소할수록 SA/PAM 하이드로겔의 팽윤 및 수용 속도가 증가함을 확인하였다. 수온 상승 시 이온결합이 불안정하고 아마이드 결합이 깨지면서 하이드로겔의 수용 속도를 증가시키는 반면, MBAAm의 밀도 감소 시에는 주요 결합력인 이온결합력이 약화되어 고온수에 취약함을 확인하였다. 본 연구를 통해 SA/PAM 하이드로겔의 수용속도의 제어가 가능함을 증명하였고 선택적 수용이 가능한 차수재로서의 가능성을 제시하였다.

Keywords: sodium-alginate/polyacrylamide hydrogel, dissolution rate, temperature effect, cross-linking density effect, selectively dissolvable water-blocking material.