Designing Self-Sustainable Icephobic Layer by Introducing a Lubricating Un-Freezable Water Hydrogel from Sodium Polyacrylate on the Polyolefin Surface

A convenient, environment-friendly, and cost-effective method to keep anti-icing for a long time was highly desirable. Slippery lubricant layers were regarded to be effective and promising for anti-icing on different surfaces, but the drought-out of lubricants and the possible detriments to the environment were inevitable. By combining super-high molecular weight sodium polyacrylate (H-PAAS) with polyolefin through a one-pot method, a self-sustainable lubricating layer with extremely low ice adhesion of un-freezable water hydrogel was achieved at subzero conditions. The lubricant hydrogel layer could auto-spread and cover the surface of polyolefin after encountering supercooled water, frost, or ice. Due to the reduction of storage modulus in the interface, the ice adhesion of the specimen surfaces was far below 20 kPa, varying from 5.13 kPa to 18.95 kPa. Furthermore, the surfaces could preserve the fairly low adhesion after icing/de-icing cycles for over 15 times and thus exhibited sustainable durability. More importantly, this method could be introducing to various polymers and is of great promise for practical applications.

Oriented proton-conductive nano-sponge-facilitated polymer electrolyte membranes

Aligned nano-sponges accommodate only non-freezable water and facilitate efficient water retention in the membrane, even under low relative humidity conditions.

Analysis of freezable water content by DSC for apple dormant bud cryopreservation

Dormant bud cryopreservation is a valuable tool for the germplasm of temperate trees preservation. Freezable water content, as an important cryopreservation characteristic, was analysed by DSC. Scions of modern apple tree varieties (Malus domestica) were collected during the winter season from orchards, freeze-dehydrated to 26–32% of water content at –5°C and cryopreserved by the two-step procedure. Samples were rehydrated in moist peat after 4 months of cryopreservation and grafted on rootstocks in a field. Regeneration by sprouting buds on rootstocks was evaluated. The varieties were divided into three groups according to their water content and percentage of crystallized water. The regeneration in the three groups decreased with decreasing bud water content. Regeneration was higher than 80% in most of the varieties and reached 100% in almost 1/3 of the tested varieties. In only one variety, was regeneration lower than 40%, which is still a high regeneration rate for considering apple genotypes as successfully cryopreserved. According to this study, the two-step cryoprotocol was successfully optimized for Central European conditions.

Melting and crystallization DSC profiles of different types of meat

The aim of this study was to test the influence of scanning rate and meat type on the thermo-physical properties of meat and content of the freezable water in frozen meat, using differential scanning calorimetry (DSC). In this study, three types of meat were investigated: beef (M. Longissimus dorsi), pork (M. Longissimus dorsi), and chicken meat (Pectoralis major). The cooling rate affected the onset (Tcon), peak (Tc) and end (Tcend) temperatures of crystallization process of beef meat (p < 0.05). Decreasing cooling rate from 20 to 2?C/min resulted in significant (p < 0.05) change of the crystallization enthalpy (?Hc) of beef meat, from -220.17 to -168.20 J/g, respectively. Reduction of the heating rate caused significant (p < 0.05) decrease in enthalpy of melting (?Hm) for beef meat, from 228.87 to 161.13 J/g. The heating rate affected the peak (Tm) and end temperatures (Tmend) of melting process of beef meat (p < 0.05). The type of meat did not have effect on ?Hc and ?Hm as well as temperature of crystallization (Tcon, Tc and Tcend) and temperature of melting (Tm and Tmend) in meat. Significant (p < 0.05) change in freezable water content were recorded between heating rate 20 ?C/min and other heating rates, for all three meat types.