Improving molecularly imprinted nanogels by pH modulation

Molecularly imprinted polymers (MIPs) are polymerized in the presence of a template molecule. After removing the template, the polymer scaffold can selectively rebind the template. The imprinting factor (IF) refers to the rebinding ratio of imprinted and non-imprinted polymers. Generally, the IFs of most reported MIPs are quite low (e.g. below 3.0). This is partially attributable to strong non-specific interactions. In this study, imprinted nanogels are prepared using two common dyes as templates, sulforhodamine B (SRhB) and fluorescein. By varying the buffer pH, non-specific electronic interactions between the template and the gels are reduced, leading to improved IF for the SRhB-MIPs from 1.5 (at pH 7.2) to 7.4 (at pH 9.0). At the same time, the binding capacity of the MIP remained similar. On the other hand, while pH tuning also improved the IF of the fluorescein-imprinted nanogels, the binding capacity dropped significantly. Using isothermal titration calorimetry (ITC), the SRhB-imprinted nanogels display a much higher affinity (Ka = 2.9 × 104 M−1) than the non-imprinted (Ka = 0.031 × 104 M−1) when rebinding is conducted in high pH (pH 9.0). This difference is mainly driven by enthalpy. This study suggests that pH tuning can be used to further improve MIPs.Natural Sciences and Engineering Research Council || STPGP 447472-1

Developing Construction Materials from Recycled Composites, Recycled Materials, and Recycling Technologies

This paper reviews the state of technology in recycling of coal fly ash, metal, glass, plastic and composite materials has been conducted. This is closely related to our daily life, as recent estimates indicate that more than 33 million tons of plastic are discarded each year, of which 6.5% are recycled and 7.7% are burned. Similar amounts of materials are discarded every year, including glass, metal and fly ash. Although much research has been performed on the recycling technologies for different common waste materials, how to apply them in constructional field and how they performed in application are quite new, with studies that are rapidly increasing in recently due to China decided not to receive any materials waste from the US, which means a high portion of discarded materials nowhere to be placed. In addition, just choosing to dispose of waste materials by landfills not only causes new environmental pollution but also wastes available resources. Therefore, from different aspects, such as the basic properties of materials, the technical means of recycling, the applications, properties, and prices after recycling, this paper comprehensively depict the circulation of these five materials

Self-healing metal coordinated hydrogels using nucleotide ligands

A supramolecular gel formed by coordination of Zn2+ with adenosine monophosphate (AMP) is reported. The adenine base, the monophosphate, and Zn2+ are all important for gel formation. Mechanically disrupted gels can re-form upon centrifugation; applications of this gel for guest-molecule entrapment are explored.Beijing Higher Education Young Elite Teacher Project || ETP0520 Fundamental Research Funds for the Central Universities || YS1407 China Scholarship Council || Natural Sciences and Engineering Research Council |

Constrained Clustering Based on the Link Structure of a Directed Graph

In many segmentation applications, data objects are often clustered based purely on attribute-level similarities. This practice has neglected the useful information that resides in the link structure among data objects and the valuable expert domain knowledge about the desirable cluster assignment. Link structure can carry worthy information about the similarity between data objects (e.g. citation), and we should also incorporate the existing domain information on preferred outcome when segmenting data. In this paper, we investigate the segmentation problem combining these three sources of information, which has not been addressed in the existing literature. We propose a segmentation method for directed graphs that incorporates the attribute values, link structure and expert domain information (represented as constraints). The proposed method combines these three types of information to achieve good quality segmentation on data which can be represented as a directed graph. We conducted comprehensive experiments to evaluate various aspects of our approach and demonstrate the effectiveness of our method