Although many rhodamine based fluorescence sensors were reported to detect metal ions with high sensitivity and selectivity, there are very few reports available to study the mechanisms of detection and the interaction between probe and metal ions. This paper aims to detect ferric ions by novel fluorescence chemosensors and study the mechanisms in detail. A novel probe AD-MAH-RhB was designed and synthesized from rhodamine B (RhB), adamantyl (AD), ethylene diamine and maleic anhydride (MAH). AD-MAH-RhB could detect Fe(3+) in aqueous solutions. The mechanism was explored by the HSAB principle, FTIR and mass spectra. The results suggested that Fe(3+) bound with amine and oxygen atoms in AD-MAH-RhB to form a complex composed of a 2 : 1 stoichiometry of Fe(3+) and the probe. Moreover, computational simulations were employed to further investigate the detection mechanism. The calculated results showed that Fe(3+) could conjugate with AD-MAH-RhB probe to form a stable complex, which was induced by synergetic effects of the suitable space and distance of van der Waals forces. However, Hg(2+) was found to disturb this detection and form a complex with 1 : 2 stoichiometry of Hg(2+) and AD-MAH-RhB. Then, another probe, β-cyclodextrin modified polymaleic anhydride (PMAH-CD) including AD-MAH-RhB (PMAH-CD/AD-MAH-RhB) was fabricated by inclusion interaction between CD and AD. PMAH-CD@AD-MAH-RhB showed high selectivity and sensitivity to Fe(3+) in the aqueous solution by eliminating the interruption of Hg(2+) possibly due to the high hydrogen interaction among the probes to inhibit the stable form complex with Hg(2+).

A variety of chemosensors have been reported for detection of metal ions. However, the metal ions could not be separated and removed at the same time for the goal of water purification. This paper presents to detect and remove metal ions from aqueous solution simultaneously by a fluorescence chemosensor and functional magnetic nanoparticles. A novel probe adamantyl (AD)-maleic anhydride (MAH)-rhodamine B (RhB) was designed and synthesized from RhB, ethylene diamine, MAH, and AD. AD-MAH-RhB showed high selectivity and sensitivity to metal ions in aqueous solution. The sensing mechanism was explored by FTIR and mass spectra. The results suggested that AD-MAH-RhB could conjugate with metal ions and form the binding complexes with various stoichiometries of probe and metal ions. Moreover, b-cyclodextrin-modified magnetic nanoparticles (CD-MNP) were fabricated and used as host materials to form inclusion complex of CD-MNP and AD-MAH-RhB-metal ions. Then, the metal ions could be removed by an outer magnet, which were confirmed by fluorescent spectrum. The probe and CD-MNP had the great potential application for sewage treatment.

Although a variety of chemosensors as probes have been exploited for the detection of metal ions with high sensitivity and selectivity, the formed probe-metal complex was hardly suitable for separation, removal, and further recovery. This paper presents a method to detect and remove metal ions from aqueous solutions simultaneously by a fluorescence chemosensor and functional magnetic nanoparticles. A novel probe SRhB-Azo was synthesized based on rhodamine B (RhB), maleic anhydride (MAH), and azobenzene (Azo). SRhB-Azo showed high selectivity and sensitivity to Hg ions in aqueous solutions. Job's experiment showed the formation of a 1:2 stoichiometry complex between Hg 2+ and SRhB-Azo. Moreover, β-cyclodextrin (β-CD)-modified magnetic nanoparticles (CD-MNPs) were fabricated and used as host materials to form the inclusion complex CD-MNP and SRhB-Azo-Hg 2+ . Then, the SRhB-Azo-Hg 2+ complex could be removed by an external magnet, and subsequently recovered by UV-irradiation-induced trans/cis isomerization of the Azo groups. The CD-MNPs could be reused for nearly four times. Thus, the SRhB-Azo probe and CD-MNP system has great potential application in sewage treatment.

The product identity is an important topic in modern design. However very little research on the cognition of product identity based on consumers' image and design model has been reported. This article has proposed the cognition concept of the product identity image, and analyzed the main method based on the image cognition. According to the features of the product identity, this study has employed some quantitative relation experiments such as semantic differential (SD), eye track observing, and qualitative analysis methods such as oral description, metaphor analysis, extracted the key features which affect the image identification and image cognition, and formed the feature database and the rule database of the image inferences. Taking this as the foundation, the study has established the prototype design model of the product identity from the input to the output, carried out the dual appraisals and the revision to the inference results using the identification model and the consumer model in the later period, and ensured the correct output.