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Polyoxometalate-based organic–inorganic hybrids have attracted considerable attention due to their fascinating structures and wide application prospects. In this work, using the same building blocks, ligands and metal ions (ZnW12O406−(ZnW12), 2,2′-bipyridine (2,2′-bipy), and Cu2+), we synthesized three new POM-based hybrids by controlling the pH values of the reaction systems. These three compounds {(Zn0.6(H2)0.4W12O40)[Cu(2,2′-bipy)(H2O)][Cu(2,2′-bipy)(H2O)2][Cu(2,2′-bipy)(H2O)3]}2·6H2O (1), (Me4N)2{ZnW12O40[Cu(2,2′-bipy)(H2O)][Cu(2,2′-bipy)(H2O)3]}·5H2O (2), and {(Zn0.5(H2)0.5W12O40)[Cu(2,2′-bipy)][Cu(2,2′-bipy)(H2O)][Cu(2,2′-bipy)(H2O)2]}·5H2O (3) have been structurally characterized by single-crystal X-ray diffraction. Compound 1 appears as a dimeric cluster structure, while compounds 2 and 3 appear as a 1D chain structure and a 2D network, respectively. The semiconducting properties of compounds 1–3 are different, which was demonstrated by band gap (Eg) and photocurrent response measurements. Compound 3 can efficiently catalyze the photooxidation of toluene to benzaldehyde with high selectivity using molecular oxygen as the oxidant component. Moreover, compound 3 was recycled and reused three times without significant degradation in conversion and selectivity. In addition, the mechanism of the photocatalytic reaction was also investigated. [ABSTRACT FROM AUTHOR]

In this study, 6 very small granule starches (VSGSs) were isolated from endosperms of dicotyledon Amaranthus cruentus , Agriophyllum squarrosum , Chenopodium quinoa , Euryale ferox , Mirabilis jalapa , and Vaccaria hispanica. Their morphologies and physicochemical properties were investigated. Most VSGSs with granule size <3 μm were spherical or polygonal, and their apparent amylose contents ranged from 19.4 to 33.1% with A. cruentus starch the lowest and E. ferox starch the highest. All VSGSs had the same A-type crystalline structure with relative crystallinities from 23.3 to 29.6%. Though 6 VSGSs had slight differences in short-range ordered structure and lamellar repeat distance, their lamellar peak intensities exhibited significant differences. The gelatinization temperatures showed significant differences among 6 VSGSs with C. quinoa starch the lowest and M. jalapa starch the highest. The 6 VSGSs had significantly different pasting viscosities with peak viscosities from 1887 to 4579 mPa s, hot viscosities from 1704 to 3479 mPa s, breakdown viscosities from 56 to 1170 mPa s, final viscosities from 2419 to 4811 mPa s, and setback viscosities from 715 to 1821 mPa s. The digestion properties of starches were significantly different among 6 VSGSs. The above results could provide some references for applications of these VSGSs. • Very small granule starches (VSGSs) were isolated from dicotyledon endosperms. • Most VSGSs had spherical or polygonal shape with granule diameters <3 μm. • Six VSGSs had amylose contents from 19.4 to 33.1% and the same A-type crystallinity. • Six VSGSs had significantly different lamellar peak intensity and thermal properties. • Six VSGSs exhibited significantly different pasting and digestion properties. [ABSTRACT FROM AUTHOR]

The crystallization chemistry of silica‐based zeolites in ionic liquids remains highly puzzling and interesting in the field of zeolite science. Herein, we report the successful ionothermal synthesis of germanosilicate zeolites. The ionothermal templating effect with respect to the structure, alkalinity and concentration of organic additives was comparatively studied. The results showed that a small amount of organic base could effectively aid the dissolution of silica source and facilitate the crystallization of germanosilicate zeolites with ionic liquid as template. Remarkably, STW and IRR structures constructed with double‐four‐ring (D4R) structure‐building units were ionothermally prepared using 1‐ethyl/butyl‐3‐methyl imidazolium and 1‐benzyl‐3‐methyl imidazolium ionic liquids as template, respectively. Ionothermal synthesis tailored with organic base showed suitable chemistry for the formation of germanium‐containing siliceous D4R units. This finding will be helpful for the rational exploration of novel extra‐large‐pore zeolitic structures. IRResistible: Germanosilicate zeolites were ionothermally prepared in the presence of organic base, which aided the dissolution of silica source and facilitated the crystallization of STW and IRR structures with ionic liquids of different structure as template. Ionothermal chemistry was effectively tailored by using an organic base, which exhibits a remarkable capability for the formation of germanium‐containing siliceous D4R units. [ABSTRACT FROM AUTHOR]

Highlights • Starch from vitreous endosperm (VS) was larger than that from floury endosperm (FS). • VS had higher amylose and damaged starch contents than FS. • VS had lower relative crystallinity and lamellar peak intensity than FS. • Native FS was more resistant to gelatinization and enzyme hydrolysis than VS. • Gelatinized and retrograded VS and FS had similar digestion properties. Abstract Starches were isolated from vitreous and floury endosperms from the same kernels, and their physicochemical properties were investigated to reveal their differences. Starch from vitreous endosperm had more surface indentations, larger granule size, and higher contents of protein, amylose and damaged starch than that from floury endosperm. Both starches from vitreous and floury endosperms exhibited A-type crystalline structure, but starch from vitreous endosperm had lower relative crystallinity and lamellar peak intensity than that from floury endosperm. Starch from floury endosperm had higher gelatinization temperature and enthalpy but lower gelatinization temperature range and percentage of retrogradation than that from vitreous endosperm. Native starch from floury endosperm was more resistant to enzyme hydrolysis than that from vitreous endosperm. Gelatinized and retrograded starches had similar digestion properties between starches from vitreous and floury endosperms. Principal component analysis indicated that starches from vitreous and floury endosperms had significant differences in their physicochemical properties. [ABSTRACT FROM AUTHOR]

The multi-scale structural dynamics of amylopectin-only barley starch (APBS), normal barley starch (NBS), and amylose-only barley starch (AMBS) digested with amylolytic enzymes for 120 min were investigated in this study. For all starches, 0–20 min was identified as a rapid digestion stage, followed by a 20–120 min slow digestion. For APBS and NBS, the content of short chains (DP ≤ 12) and the thickness of crystalline and amorphous nano-lamellae increased, whereas the crystallinity decreased, and pores were generated on the granular surface during the rapid digestion stage. At the following slow digestion stage, the branching degree and relative amount of double helices increased, the crystalline and lamellar structures were lost, and the hydrolyzed starch segments aggregated. For AMBS, the rapid digestion stage was characterized by an increased content of short chains (DP ≤ 8) and B-type crystals and decreased amounts of V-type crystals. Furthermore, the lamellar and granular structures were lost, and digestion residues aggregated during the first stage of AMBS, which were formed in the second digestion stage of APBS and NBS. The second slow digestion stage of AMBS was characterized by an increased branching degree and a decreased relative content of single helices. It is suggested that the aggregated digestion residues at the initial digestion stage are the main reason for the overall low digestibility of AMBS. [Display omitted] • Amylose barley starch (AMBS) lost granular structure at initial digestion stage. • AMBS reorganized immediately and was thereafter hydrolytic resistant. • Single helices and the V-type crystals decreased in AMBS upon hydrolysis. • Amylopectin barley starch (APBS) first generated pores and then reorganized. • APBS had a high content of double helices after digestion. [ABSTRACT FROM AUTHOR]

Enzymatic modification of foods is an important tool for enhancing starch functionality due to its safety, high efficiency, and specificity. Enzymatic modification of gelatinized starch systems is well reported in literature. However, to our knowledge, a review describing and comparing the effects of granular vs. gelatinized systems and enzyme-assisted modification of starch is both timely and lacking. We summarize, discuss and point at future aspects of the consequences of using various techniques of enzymatic treatment of granular and gelatinized starch for modifying their structure and physicochemical properties, including the crystalline and granular structure, and functional properties. For gelatinized starch systems, we generally discuss catalytic mechanism, substrate specificity and product molecular structures for different types of starch-acting enzymes with emphasis on the resulting molecular structures. We critically discuss the problems of enzyme attack on granular starch in relation to two common strategies for starch granular pretreatment, namely, the preparation of porous starch and cold water-swelling of granular starch, both aim at increasing the enzyme catalytic efficiency. Finally, we point out research directions to expand the applications of enzymatic treatments in starch modification. The catalytic efficiency of starch-acting enzymes is higher on amorphous gelatinized starch than on semi-crystalline granular starch. To enhance the catalytic efficacy on granular starch, granules can be engineered to allow for a more efficient enzyme binding on granular surfaces. Additionally, we in-depth describe efforts to increase the specific surface area of starch granules by I) generating pores and channels at the granular surface via treatment with hydrolases or by II) swelling granules via e.g., thermal pretreatment in the presence of ethanol. It is generally found that strategy I reduces the starch yield due to the hydrolytic effect, decreasing the pasting properties. Strategy II retains a high yield of the starch product and generates granular starch with high pasting stability. • Enzymatic techniques to modify granular starch are emerging. • Enzymes have higher catalytic efficiency on gelatinized than on granular starch. • When acting on gelatinized starch, enzymes only alter the molecular structure. • In granular systems, enzymes alter molecular, crystalline and granular structures. • Porous and partly swollen starch granules are effectively modified by enzymes. [ABSTRACT FROM AUTHOR]

Abstract It remains a challenge to continuously control the nitrogen concentration x , as well as the physical properties, of ε-Fe 3- x N epitaxial films. Here ε-Fe 3- x N polycrystalline and [001]-oriented epitaxial films with x between 0.07 and 0.87 were simultaneously sputtered on glass and MgO(111) substrates. The surface of the films is made up of triangle and quasi-hexagonal particles which correspond nicely to the hexagonal crystal structure of ε-Fe 3- x N. Both ε-Fe 3- x N polycrystalline and epitaxial films show metallic behavior and, more importantly, the contribution of magnetic scattering to the resistivity increases as x increases. The saturation magnetization of 5 K decreases monotonically from 1060 to 150 kA/m with increasing x. What is noteworthy is that the in-plane coercivity force of epitaxial films is far less than that of polycrystalline counterparts. Specifically, the coercivity of ε-Fe 2.93 N epitaxial film is ≤2.39 kA/m. Highlights • ε-Fe 3- x N(001) epitaxial films with x adjustable are grown on MgO(111) substrates. • Magnetic scattering has a significant influence on the resistivity of ε-Fe 3- x N. • The saturation magnetization of ε-Fe 3- x N falls in between 1060 and 150 kA/m. • The coercivity of ε-Fe 2.93 N epitaxial film is less than 0.8 kA/m at 300 K. [ABSTRACT FROM AUTHOR]

Abstract: Composite zeolites composed of MOR and FAU (denoted as MFZ) were synthesized by a two-step hydrothermal crystallization procedure, in which the mixture of pre-synthesized mordenite zeolite acts as the nutrients for the growth of post-synthesized Y zeolite. The structural, crystalline, and textural properties of the as-synthesized materials, as well as the references Y and mordenite zeolite samples, were characterized by XRD, FT-IR, in situ IR spectrometry of pyridine, NH3-TPD, N2 adsorption–desorption and SEM; the composite zeolites and the corresponding physical mixture were investigated during isopropylbenzene catalytic cracking. The results show that the ratio of MOR to FAU in the as-synthesized composite zeolites largely depends on the second-step crystallization time. When the crystallization time is 10–17h, a composite with different ratio of MOR to FAU can be obtained; as compared with the corresponding physical mixture, the composite sample has a higher isopropylbenzene conversion and a longer catalytic life due to the introduced hierarchical pores system. The catalytic activity of isopropylbenzene cracking over the catalysts has a linear dependence with the revised hierarchy factor (HF′). [Copyright &y& Elsevier]