Department of Chemical Engineering, Imperial College London, SW7 2AZ, United Kingdom.
Langmuir. 2010 Dec 21;26(24):19027-32. doi: 10.1021/la103683h. Epub 2010 Nov 19.
Three-dimensional (3D) chemical information was obtained by means of a combination of two-dimensional attenuated total reflection Fourier transform infrared (ATR-FT-IR) imaging with a focal plane array detector and variable angle depth profiling. Since the penetration depth of the evanescent wave in ATR spectroscopy is not limited by diffraction, it was possible to resolve thin sandwiched polymer layers nondestructively within a stack of polymer layers. Chemical images were obtained from layers of different thickness of the laminate by moving a custom-made aperture to specific positions on the condenser lens of the ATR accessory. Sequences of absorption images detect the successive appearance of thin, buried layers of polybutylmethacrylate (d(PBMA) = 400 nm) and polycarbonate (d(TMPC) = 300 nm) in different depths of the stack of polymer layers. The depth resolution of variable-angle ATR-FT-IR imaging is sufficiently high to detect surface roughness at the interface between different polymer layers. Two different stacks of polymers with reordered sandwich-layers were imaged simultaneously, demonstrating the potential of variable angle ATR-FT-IR for 3D-imaging of a sample with xyz-heterogeneity, which can be a powerful analytical technique for materials science and biomedical research.
通过二维衰减全反射傅里叶变换红外（ATR-FT-IR）成像与焦平面阵列检测器和可变角度深度剖析相结合，获得了三维（3D）化学信息。由于 ATR 光谱中消逝波的穿透深度不受衍射限制，因此可以在聚合物层的堆叠中无损地分辨出薄的夹层聚合物层。通过将定制孔径移动到 ATR 附件的聚光透镜的特定位置，可以从层压材料的不同厚度层获得化学图像。吸收图像序列检测到聚甲基丙烯酸丁酯（d(PBMA) = 400nm）和聚碳酸酯（d(TMPC) = 300nm）的薄埋层在聚合物层堆叠的不同深度处的连续出现。可变角度 ATR-FT-IR 成像的深度分辨率足够高，可以检测不同聚合物层之间界面处的表面粗糙度。同时对两个具有重新排列夹层的不同聚合物层进行成像，展示了可变角度 ATR-FT-IR 对具有 xyz 异质性的样品进行 3D 成像的潜力，这可能是材料科学和生物医学研究的一种强大分析技术。
