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The in situ polymerization of monomers to form a second network within a preexisting network (first network) is a facile and effective strategy to fabricate semi-interpenetrating (semi-IPN) hydrogels with enhanced mechanical strength; while to comprehend the effects of the first polymer network on the polymerization process of the second network is still a challenging project. This paper introduces a simple method of employing dynamic rheological measurement loops to monitor the real time progress of the in situ polymerized acrylamide (AAm) in a chitosan (CS) solution towards the formation of a semi-IPN hydrogel. To identify the effects of the preexisting network on the polymerization gelation process, the concept “Effective Conversion Ratio (ECR)” is introduced to evaluate the first network effects on the requirement for the polymerized conversion ratio of the second network to form a critical gel. The rheological properties before gel point, at gel point, and at post-gel stage are discussed via the obtained real time data, respectively. The experimental results have proved the suitability of utilizing dynamic rheology to obtain the real time details of the semi-IPN gel fabrication process.

The effect of Fe-C alloy additions on thermal, mechanical and corrosive properties of (Cu50Zr40Ti10)1-x(Fe-C)x (x = 0–2.20 at%) alloys were systematically investigated. The results show that the Fe and C additions can enhance glass transition temperature Tg and onset crystallization temperature Tx, but narrow supercooled liquid region ΔTx. Work-hardening can be clearly observed for the Cu-based bulk metallic glasses (BMGs) containing Fe and C elements. The yield strength (σy), fracture strength (σf) and plastic strain (ep) are drastically increased by Fe-C alloy additions. The corrosion potential Ec increases and the corrosion current density ic decreases with increasing Fe and C contents. The studied Cu-based BMGs exhibit unique and novel anodic polarization behavior characterized by current platforms plus current serrations. The current serrations are much larger for the Cu-based BMGs with 0 ≤ x ≤ 1.32 at% than for those with 1.76 ≤ x ≤ 2.20 at%. The corrosion surface images are changed from the pits to the passive films by Fe-C alloy additions. The corrosion behavior gradually transforms from the pitting corrosion to the self-passivization with increasing Fe and C contents. The corresponding mechanisms are also discussed.

(Zr54Al10.2Ni9.4Cu26.4)100−xTix (x = 0–0.5, at%) bulk metallic glasses were prepared by water-cooled copper suction casting method. The Ti microalloying effect on glass forming ability and physical and chemical properties of Zr54Al10.2Ni9.4Cu26.4 glass forming alloy were systematically investigated. The glass forming ability is the largest for the Zr-based alloy with 0.3 at% Ti. The glass transition temperature is decreased by the Ti addition, while the supercooled liquid region is broadened. Both strength and plasticity are significantly enhanced by the Ti addition. The yield strength and the fracture strength firstly increase and then decrease when the Ti content reaches up to 0.3 at%. The plastic strain and the fracture strain increase with increasing Ti content. In addition, the corrosion potential is slightly decreased by the Ti addition. The corrosion current density increases with increasing Ti content. The pitting corrosion becomes increasingly serious with increasing Ti content. The honeycomb corrossion structure can be clearly observed when the Ti content reaches up to 0.5 at%. The corresponding mechanisms are also discussed in detail.

This paper introduces a tripeptide (β-Asp-Phe-Phe, abbreviation β-AspFF) which can self-assemble into long nanofibrils in toluene solvent and further entangle to organogels. The nanofibrils of β-AspFF can serves as ligands to incorporate with Co(II) in the organogels. After being re-immersed into HFIP-H2O mixed solution (Volume Ratio, 1:1), the β-AspFF-Co(II) xerogel exhibited decent oxygen binding properties. Impressively, in comparing with β-AspFF-Co(II) complex, the β-AspFF-Co(II) xerogel proved to be a higher efficient catalyst for catalyzing cyclohexene oxidation reaction. We therefore suppose that the porous and nanofibrils structure of the xerogel plays a key role to improve the catalytic behavior of β-AspFF-Co(II) complex.

(Zr53Al11.6Ni11.7Cu23.7)1-x(Fe77.1C22.9)x (x = 0–2.2 at.%) bulk metallic glasses (BMGs) were prepared by water cooling copper mold suction casting and their isochronous crystallization characteristics are investigated. The glass transition temperature, crystallization temperature, and crystallization peak temperature for all studied Zr-based BMGs firstly increase with increasing heating rate, and then decrease when the heating rate increases up to 60 K/min for the BMGs (0 ≤ x ≤ 0.88 at.%) and 80 K/min for the BMGs (1.32 ≤ x ≤ 2.20 at.%). The glass transition temperature, crystallization temperature, glass transition activiation energy, crystallization activiation energy, and activiation energy for crystallization peak temperature of the Fe- and C-free Zr-based BMG are the smallest among the studied BMGs, indicating that Fe and C additions are benificial to delaying the glass transition and the crystallization. Fe and C additions influence more significantly on the glass transition than on the crystallization. The local crystallization activiation energy for the Fe- and C-free BMG are the smallest among the studied BMGs, indicating that the crystallization is easy for the Fe- and C-free BMG. The peak height of local Avrami exponent and its corresponding crystallization fraction decrease with increasing heating rate except for the BMG (x = 1.32 at.%). The fragility indexes are 32–48 for the studied Zr-based BMGs. The present results are of guiding significance for preparing the excellent BMG composites by heat treatment and selecting suitable conditions for forming the BMGs.

The growth mode of m-plane AlN crystal grown by physical vapor transport method is studied. The m-plane AlN crystal fabricated by spontaneous nucleation was used as a seed to grow bulk crystal, and 3-mm thick AlN crystals with a maximum lateral dimension of 20 mm were obtained. The Raman tensor elements of A1(TO), E2(high) and E1(TO) Raman models from the m-plane AlN crystal are investigated by angle-dependent polarized Raman scattering. The Raman tensor comparing with our previous report indicates the possible enhancement of the Raman tensor in the directions vertical to [0002] direction at higher growth temperature.

A series of small molecular weight organogelators have been synthesized and studied. One as prepared organogel, named BDOT (n = 10) has exhibited excellent adsorption rate (97%) toward high concentrated mercury ions (0.01 M) from aqueous solution. The gelator itself can also serve as in situ colorimetric chemo sensor of Hg2+ hereinto.

Powders of two-phase B2/L21 Fe30Ni20Mn20Al30 (in at.%) were mechanically milled, and both as-milled powders and powders annealed at 823 K were examined using a combination of X-ray diffractometry, scanning electron microscopy and transmission electron microscopy. The as-milled powder consisted of B2 (ordered b.c.c.) phases, whereas after a short anneal at 823 K β-Mn-structured precipitates were present and recrystallized B2 grains were observed in a L21 matrix. The longer the milling time, the finer the resulting powder size and the shorter the annealing time before precipitation occurred. The latter behavior is believed to be associated with nucleation occurring on dislocations formed during milling.

The effects of directional solidification (DS) processing on the microstructure and hardness of Fe 35 Ni 15 Mn 25 Al 25 are examined. The microstructure consists of (Fe, Mn)-enriched B2-ordered (ordered b.c.c.) and (Ni, Al)-enriched L2 1 -ordered (Heusler) phases aligned along directions in a complex percolating morphology. Because of the slow cooling rate during DS processing, the phase size in the DS alloy was approximately 3 times greater than that of an arc-melted alloy. Precipitates were found within both phases of the as-DS alloy, but not in the as-arc-melted alloy. Upon annealing, the phase size increased but with no significant change in the composition of the phases, while the interphase interfaces appeared to become sharper. The hardness of the DS alloy increased monotonically upon annealing, and showed an inverse relationship with the phase size before the formation of large β–Mn-structured precipitates. Several theoretical models are considered that might explain this variation of hardness with phase width. Longer annealing resulted in growth of the β–Mn-structured precipitates, causing a further 50% hardness increase.

Cooling rate-induced softening in Y-based metallic glasses were verified in this work. By varying the speed of the roller in the melt-spinning process, it is found the hardness of the ribbon decrease with the cooling rate. Nanoindentation test also indicated that the ribbon at a higher cooling rate shows higher deformation energy. Contrary to crystalline materials, whose hardness usually increases with the cooling rate, the softening of metallic glasses is attributed to high concentration of defects frozen by fast cooling, and thus more structural relaxation during deformation.