کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
600600 1454305 2012 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Light-induced spatial control of pH-jump reaction at smart gel interface
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Light-induced spatial control of pH-jump reaction at smart gel interface
چکیده انگلیسی

We proposed here a ‘smart’ control of an interface movement of proton diffusion in temperature- and pH-responsive hydrogels using a light-induced spatial pH-jump reaction. A photoinitiated proton-releasing reaction of o-nitrobenzaldehyde (NBA) was integrated into poly(N-isopropylacrylamide-o-2-carboxyisopropylacrylamide) (P(NIPAAm-co-CIPAAm)) hydrogels. NBA-integrated hydrogels demonstrated quick release of proton upon UV irradiation, allowing the pH inside the gel to decrease below the pKa of P(NIPAAm-co-CIPAAm) within a minute. The NBA-integrated gel was shown to shrink rapidly upon UV irradiation without polymer “skin layer” formation due to a uniform decrease of pH inside the gel. Spatial control of gel shrinking was also created by irradiating UV light to a limited region of the gel through a photomask. The interface of proton diffusion (“active interface”) gradually moved toward non-illuminated area. The apparent position of “active interface”, however, did not change remarkably above the LCST, while protons continuously diffused outward direction. This is because the “active interface” also moved inward direction as gel shrank above the LCST. As a result, slow movement of the apparent interface was observed. The NBA-integrated gel was also successfully employed for the controlled release of an entrapped dextran in a light controlled manner. This system is highly promising as smart platforms for triggered and programmed transportation of drugs.

Figure optionsDownload as PowerPoint slideHighlights
► A control of an interface movement of proton diffusion in smart hydrogels was studied.
► Photoacid generator was integrated into temperature- and pH-responsive hydrogels.
► A light-induced pH-jump reaction was driven in the gel.
► Spatial and temporal controls of gel shrinking were achieved in a light controlled manner.
► Drug release was successfully triggered by UV irradiation.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Colloids and Surfaces B: Biointerfaces - Volume 99, 1 November 2012, Pages 53–59
نویسندگان
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