This review paper summarizes the recent research progress in the underlying mechanisms behind the shape memory effect (SME) and some newly discovered shape memory phenomena in polymeric materials. It is revealed that most polymeric materials, if not all, intrinsically have the thermo/chemo-responsive SME. It is demonstrated that a good understanding of the fundamentals behind various types of shape memory phenomena in polymeric materials is not only useful in design/synthesis of new polymeric shape memory materials (SMMs) with tailored performance, but also helpful in optimization of the existing ones, and thus remarkably widens the application field of polymeric SMMs.

The efficient industrial conversion of plant-derived cellulose to simple sugars and other value-added chemicals requires various highly stable and reactive enzymes. Industrial processes especially synchronous saccharification and fermentation (SSF)-based production of cellulosic bio-ethanol require enzymes that are active at lower temperatures. In this study, we have identified, characterized, and expressed the cold-adaptive endo-1,4-β-glucanase (BpEG) isolated from the Burkholderia pyrrocinia JK-SH007. The analysis of the predicted amino acid sequence indicated that BpEG belongs to GH family 8. The BpEG without the signal peptide was cloned into the expression vector pET32a and significantly expressed in Escherichia coli BL21 (DE3) competent cells. The SDS-PAGE and Western blot analysis of BpEG revealed that the recombinant BpEG was approximately 60 kDa. Purified recombinant BpEG exhibited hydrolytic activity against carboxymethyl cellulose (CMC) and phosphoric acid swollen cellulose (PASC), but not crystalline cellulose and xylan substrates. High performance, anion exchange, chromatography-pulsed amperometric detector (HPAEC-PAD) analysis of the enzymatic products obtained from depolymerization of 1,4-β-linked biopolymers of different lengths revealed an interesting cutting mechanism employed by endoglucanases. The recombinant BpEG exhibited 6.0 of optimum pH and 35°C of optimum temperature, when cultured with CMC substrate. The BpEG enzyme exhibited stable activity between pH 5.0 and 9.0 at 35°C. Interestingly, BpEG retained about 42% of its enzymatic activity at 10°C compared to its optimal temperature. This new cold-adaptive cellulase could potentially achieve synchronous saccharification and fermentation (SSF) making BpEG a promising candidate in the fields of biofuel, biorefining, food and pharmaceutical industries.

Based on the room-temperature phosphorescence (RTP) peculiarity of Mn-doped ZnS quantum dots (QDs), a bifenthrin sensor was fabricated by coupling molecular imprinted polymers (MIPs) on the surface of silane modified QDs via atom transfer radical polymerization (ATRP). The stepwise synthesis was realized with ZnS QDs-NH₂-Br as the initiator, methacrylic acid (MAA) as the functional monomer, divinylbenzene (DVB) as the cross-linker, CuBr as the catalyst and 2,2′-bipyridine as the complexant. The smart RTP probe for bifenthrin was gained by surface molecular imprinting technology (SMIT) that can not only produce the stable RTP intensity of Mn-doped ZnS QDs, but can also enable more efficient recognition of the target molecule. The results presented show that the detection limit of the probe was 16.7 μg L⁻¹. The RTP stability, selectivity and sensitivity of the bifenthrin sensor were evaluated by using a spectrophotometer. The high sensitivity was due to an electron-transfer mechanism between the target and the QDs, and the particular selectivity was due to SMIT. Therefore, this novel strategy combines RTP of Mn-doped ZnS QDs with ATRP to use the best aspects of both. It offers the advantages of straightforward preparation and processing, fast response, low toxicity and optical stability, so it is very promising for the detection of bifenthrin.