Addition/Correction pubs.acs.org/JPCC
Correction to “Tunable Permittivity in High-Performance Hyperbranched Polyimide Films by Adjusting Backbone Rigidity” Xingfeng Lei, Mingtao Qiao, Lidong Tian, Yanhui Chen,* and Qiuyu Zhang* J. Phys. Chem. C 2016, 120 (5), 2548−2561. DOI: 10.1021/acs.jpcc.5b11667 from 1 kHz to 1 MHz for all samples. At a given frequency, the relative permittivities differ from each other due to the different backbone chemistries and molecular structures. As plotted in Figure 10b, for HBPI films, the relative permittivity (determined at 106 Hz) decreases (standard deviation = 2.67 × 10−4, R2 = 0.99) with increasing DMBZ fraction, whereas dielectric loss tan δ gradually increases (standard deviation = 0.063, R2 = 0.99).
In our original article, an error has recently been found in illustrating the frequency dependence of the relative permittivity in Figure 10a (p 2558). When the measurement frequency exceeds ∼6 MHz, the relative permittivity of the resulting hyperbranched polyimide (HBPI) films is decreased to under 1.0, that is, the relative permittivity of the vacuum. As a matter of fact, this phenomenon is almost impossible. Generally, the relative permittivity of a polymer material is higher than that of the vacuum, which means the relative permittivity should be over 1.0. In our original article, the dielectric property was determined on an Agilent 4294A precision impedance analyzer (Agilent Technologies) within the frequency range 1 kHz to 50 MHz. Due to the inherent defects of testing theory and methods, the data provided by the Agilent 4294A precision impedance analyzer may have considerable error when the measurement frequency is above 1 MHz. Therefore, to avoid any misunderstanding, we correct Figure 10. As shown here in Figure 10a, we delete the relative permittivity and dielectric loss tan δ when the frequency surpasses 1 MHz. As we refer to our original article, this correction does not affect any conclusions reported in the article. The authors apologize for any confusion caused by this error. Figure 10a depicts the variation curves of the relative permittivity (εr) and dielectric loss tan δ over the frequency ranging
Figure 10. Graphs of (a) variation curves of the relative permittivity and dielectric loss tan δ over the frequency ranging from 1 kHz to 1 MHz for all samples; the relative permittivity and dielectric loss tan δ of HBPI films at 1 MHz graphed versus (b) DMBZ fraction and (d) film density; (c) water absorption and water contact angle graphed versus DMBZ fraction for resulting HBPIs. The specific data are summarized in Table S3 of the Supporting Information.
© XXXX American Chemical Society
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DOI: 10.1021/acs.jpcc.6b09332 J. Phys. Chem. C XXXX, XXX, XXX−XXX
