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The article presents an application of curcumin, a widely available and cost-effective organic dye, to control visible-light mediated ATRP. A two-component photocatalytic system composed of curcumin and an amine-based electron donor activates alkyl bromide and controls radical polymerizations by a reductive quenching pathway. The polymerizations of various types of (meth)acrylates were performed under blue LED irradiation (λmax = 460 nm, 5 mW cm−2). The effect of electron donor type, solvent, photocatalyst and electron donor concentration, target degree of polymerization (DPtarget) etc. on the metal-free ATRP of methyl methacrylate (MMA) and poly(ethylene glycol) methyl ether methacrylate (OEGMA500) was systematically investigated to optimize the polymerization conditions. Moreover, comestible curcumin of four different brands available in the market as kitchen spices was used, which makes this approach economical (∼0.04 € for 15 g of turmeric). In order to increase the applicability of the curcumin-based polymerization strategy, the concept was extended to the polymerization of other methacrylates – butyl methacrylate (nBMA), di(ethylene glycol) methyl ether methacrylate (DEGMA), 2-(dimethylamino)ethyl methacrylate (DMAEMA), and acrylates i.e. poly(ethylene glycol) methyl ether acrylate (OEGA480), n-butyl acrylate (nBA) and 2-hydoxyethyl acrylate (HEA). In situ chain extension experiment demonstrated the preservation of chain-end functionality, enabling the facile synthesis of well-controlled copolymers.

A kind of graphitic carbon nitride (TSC−550) with high polymerization degree and improved surface property was prepared by a new precursor of thiosemicarbazide. The sulfur motif and high nitrogen content in thiosemicarbazide promoted the polymerization of thiosemicarbazide to form graphitic carbon nitride framework with high degree of polymerization, which significantly influenced the electronic structure and surface chemical properties. TSC−550 possessed a narrow bandgap of 2.19 eV that facilitated the utilization of visible light, and possessed a less positive charge, acidic surface that resulted in enhanced hydrogen adsorption ability in water solution, which promoted the H2 evolution kinetics. In addition, the extended π-conjugated electronic system promoted the separation and migration of photo-generated charge carries in plane of TSC−550 framework, as well as the increasing interlayer C–N interactions in TSC−550 created conductive paths across the layers to tunnel interlayers for rapid electron transportation. As a result, TSC−550 nanosheets showed excellent photocatalytic H2 production activity, the AQY achieved 36.4% at 425 nm.

In order to study reactivity and reaction mechanism of Al-polytetrafluoroethylene (PTFE) mechanically activated energetic composites, reaction molecular dynamics simulation was carried out to predict the pyrolysis process of PTFE. Then the reaction mechanism of PTFE pyrolysis products with Al was calculated by using density functional theory (DFT). Furthermore, the concentrated ignition characteristics were characterized. Finally, the pressure and temperature during the reaction process of Al-PTFE were tested, and the chemical structure before and after heating reaction were researched. Calculation and experimental results show that the main pyrolysis products of PTFE are C2, F, CF2, CF and CF3, and the degree of polymerization has little effect on the pyrolysis products. Among CF2, CF and CF3, it can be found that the energy barrier of reaction between CF3 and Al is the smallest (only 2.39 kJ•mol−1). The mechanical activation process can give higher reactivity to Al-PTFE mixture during concentrated ignition process.The reaction process of the decomposition of PTFE starts at 718K, and then the thermit reaction between the free radicals of decomposition products and Al begins at 898K.

Polymerization is a major challenge for the upgrading of bio-oil to biofuels, but is preferable for the production of carbon material from bio-oil. Understanding the mechanism for polymerization is of importance for tailoring property of carbon material. This study investigated the characteristics for the polymerisation of furfural, vanillin, their cross-polymerization and the impacts of catalysts on their polymerization. The results indicated that the organic acids like acetic acid and formic acid could catalyze the polymerisation of furfural, while H2SO4 or NaOH as catalyst could drastically enhance the degree of polymerization of furfural. Vanillin showed a higher tendency towards polymerization than furfural and H2SO4 or NaOH significantly facilitated the polymerization of vanillin via shifting the pasty product to solid polymer. The cross-polymerization between furfural and vanillin occurred even in the absence of catalyst, while the presence of H2SO4 or NaOH catalyst resulted in the formation of more solid polymer via cross-polymerization. The polymerisation reactions were accompanied with the consumption of –C=O via aldol addition/condensation reactions. In addition, the morphology and thermal stability of the polymers formed were affected by both the type of the catalysts employed, which can in turn enhance the cross-polymerization between furfural and vanillin.

The world of food chain produces tons of waste materials each day which is leaving carbon footprints over the environment. Fish is one of these crucial food entities. The fish scale composite was developed using natural (from trees) organic binders. These scales have enormous mechanical properties which can be utilized by layering up the scales with a natural binder. The composite was dried in the air for twenty-four hours. The samples were characterized using SEM for surface morphology together with EDS for chemical composition. Mechanical properties through Charpy impact and Shore D hardness tests were illustrated. FTIR performed to identify available functional groups and the degree of polymerization. XRD investigates the phases.

Chitooligosaccharides (COS) is a kind of functional carbohydrates with great application potential as its various biological functions in food, cosmetics, and pharmaceutical fields. Exploring the relationship between structure and function of chitosanase is essential for the controllable preparation of chitooligosaccharides with the specific degree of polymerization (DP). GsCsn46A is a cold-adapted glycosyl hydrolase (GH) family 46 chitosanase with application potential for the controllable preparation of chitooligosaccharides. Here, we present two complex structures with substrate chitopentaose and chitotetraose of GsCsn46A, respectively. The overall structure of GsCsn46A contains nine α-helices and two β-strands that folds into two globular domains with the substrate between them. The unique binding positions of both chitopentaose and chitotetraose revealed two novel sugar residues in the negatively-numbered subsites of GH family 46 chitosanases. The structure-function analysis of GsCsn46A uncovers the substrate binding and catalysis mechanism of GH family 46 chitosanases. Structural basis mutagenesis in GsCsn46A indicated that altering interactions near +3 subsite would help produce hydrolysis products with higher DP. Specifically, the mutant N21W of GsCsn46A nearly eliminated the ability of hydrolyzing chitotetraose after long-time degradation.

In the manuscript, water-soluble polysaccharides WPNI was extracted from notopterygium incisum roots and separated into two homogeneous fractions WPNI-A-a and WPNI-A-b. WPNI-A-a was an arabinogalactan (AG). WPNI-A-b belonged to HG type pectin. The structure of WPNI-A-b was analyzed by FT-IR, NMR, enzymatic hydrolysis (Endo-PG) and UPLC-FLD-MSn. WPNI-A-b was dominated by HG domain, covalently linked with AG and RG-II domains. Oligogalacturonides produced by Endo-PG from HG domain were non-, mono-, di- or tri-methyl esterified with degree of polymerization (DP) from 1 to 6. The distribution of methyl-ester groups was in a block-wise manner. The interaction of WPNI-A-b and its enzymatic hydrolysis products with galectin-1, galectin-3, galectin-7 and galectin-8 showed that AG domain exhibited stronger binding avidity to galectins than RG-II and HG domain, while oligogalacturonides showed no binding activities to galectins. The results would be useful for the application of the pectin from notopterygium incisum.

In this research, nanocellulose crystal (NCC) grafted with lactic acid (LA) oligomer was synthesized by one-pot method and used to reinforce the poly( l -lactic acid) (PLLA) matrix. FT-IR, XRD, and 13C NMR were used to analyze the structure of modified nanocellulose crystal (g-NCC). The results of GPC suggested that the degree of polymerization of the grafted segments was 23, and the degree of hydroxyl substitution of g-NCC was 2.4%. For the g-NCC/PLLA composite, its crystallization rate increases significantly compared with pure PLLA, indicating that g-NCC acted as a nucleating agent to promote the crystallization. Moreover, tensile strength of the composite materials was significantly improved from 41.9 MPa to 53.9 MPa due to the enhanced compatibility. This study provides a fast and effective modification method for g-NCC/PLLA biodegradable composites. According to the above-mentioned experimental results, the g-NCC/PLLA composites can be considered as a potential material in the packaging field, mainly due to its proper biological and physicochemical properties.

(1-x) (K2O–Na2O–2Nb2O5)-x (2BaO–Nb2O5–2SiO2) glass-ceramics with x = 0.10, 0.15, 0.20, 0.25 have been successfully prepared by traditional melting method. XRD and microstructure analysis demonstrate that all glass-ceramics are crystallized into uniform Na0.9K0.1NbO3 and K2(NbO)2(Si4O12) ferroelectric crystalline phase. Increasing x promotes the formation of Ba2NaNb5O15 phase with a tungsten bronze structure. Raman and complex impedance data confirmed that Ba2+ is introduced to repair the disruption of the glass network and make carrier migration difficult when x = 0.15. Thus, the x = 0.15 glass-ceramic sample possesses a maximum calculated energy storage density of 2.32 J/cm3 under 820 kV/cm because of a high degree of polymerization (DOP) glass network structure. Moreover, the pulsed discharge-charge tests are carried out to evaluate actual energy storage performance.

Early-age carbonation can make a significant difference in the formation of hydration products in cement-based materials and alter the microstructural and mechanical performances. To understand in detail the impacts and their contribution to cement hydration, dry-mix cement pastes were exposed to instant carbonation with 0.04 %, 1%, 3%, 10 %, 20 % CO2 concentrations for 2 h prior to further water curing. By increasing the CO2 concentration, an increment in strength gain of samples at 2 h (right after early carbonation) as well as being prolonged by water curing at 1, 3, 7 days was noticed. This agrees with TGA and XRD results, demonstrating that the increases in CO2 concentration resulted in a higher carbonation reaction and hydration degree. 29Si NMR results also indicate that the higher the CO2 concentration the lower the calcium to silica ratio (Ca/Si); thus, there is a higher degree of polymerization to promote early hydration. It can be concluded that early carbonation of 2 h in particular with a high CO2 concentration can be beneficial for further cement hydration due to the consumption of calcium hydroxide (CH) and nuclei site effect of calcite crystals, resulting in better microstructural properties and mechanical performance.

The catalytic fast pyrolysis of cellulose impregnated with phosphoric acid (H3PO4) offers a promising method for the selective production of levoglucosenone (LGO), a valuable anhydrosugar product. However, the fundamental mechanism for selective LGO formation is unclear. Herein, quantum chemistry calculations and catalytic fast pyrolysis experiments were performed to reveal the formation mechanism of LGO in H3PO4-catalyzed cellulose pyrolysis. H3PO4 significantly decreased the energy barriers of the pyrolytic reactions and altered the competitiveness of the LGO formation pathways, promoting LGO formation. Through different pathways in the non-catalytic and H3PO4-catalyzed conditions, LGO is mainly produced from the primary decomposition of glucose units of cellulose and secondary conversion of levoglucosan. The major catalytic formation pathways of LGO comprise similar reactions, with dehydration at the 3-OH + 2-H site as the rate-determining step. Importantly, secondary conversion of 1,4;3,6-dianhydro-α- d -glucopyranose is not feasible for LGO formation, in contrast to previous reports. In addition, a high degree of polymerization is beneficial for the selectivity of LGO formation in the catalytic process, because the glycosidic bond is important for the formation of the bicyclic structure (1,5- and 1,6-acetal rings).

We investigated the physicochemical properties of starches extracted from Vigna angularis variants Noto-dainagon, Kyoto-dainagon, dainagon, and erimo-type adzuki beans. The particle size was larger in the Noto-dainagon starch than in the other starches, but all starches displayed a C-type crystal structure in the X-ray diffraction analysis. The onset and peak temperatures of gelatinization were approximately 7 °C lower in the Noto-dainagon and Kyoto-dainagon starches than in the dainagon and adzuki bean starches. The dainagon and adzuki bean starches also demonstrated lower swelling power at 60 °C than the other starches. The rapid visco-analyser curves of all starches showed no breakdown during the heating process, and the final viscosities of the starches increased with decreasing temperature. The apparent amylose and phosphorus contents were highest in the Noto-dainagon starch (36.6% and 95.6 ppm, respectively). The branched- chain length degree of polymerization 6–12 was lowest in the adzuki bean starch. In vitro and in vivo analyses of the digestive properties indicated that dainagon starch was more indigestible than the other starches. We considered that dainagon starch was a potentially viable health-promoting ingredient.

Summary Translation of the outstanding mechanical performance of individual nanocellulose to macroscopic nanocellulose films can be achieved by various alignment techniques. However, attention has seldom been paid to the degree of polymerization (DP) of cellulose that plays a pivotal role in increasing the mechanical strength of nanocellulose films. In this work, nanocellulose film with superior tensile strength (1,014.7 ± 69.1 MPa) is presented by a cellulose DP protection strategy. An alkaline sulfite-anthraquinone-methanol pulping is applied to not only rapidly remove most of lignin and hemicellulose from wood blocks, which facilitates the formation of hydrogen bonds among neighboring fiber cell walls in subsequent mechanical pressing, but also to significantly suppress the decomposition of cellulose DP. Such strong nanocellulose film sheds light on unlocking the exceptional mechanical potential of cellulose and has the potential for use in advanced applications traditionally dominated by nonrenewable materials such as plastics, glass, and metals.

The effects of MgO/Al2O3 ratio on the viscous behaviors of MgO–Al2O3–TiO2–CaO–SiO2 systems were investigated by the rotating cylinder method. Raman spectroscopy was used to analyze the structural characteristics of slag and Factsage 7.0 was adopted to demonstrate the liquidus temperature of slag. The results show that the viscosity and activation energy for viscous flow decrease when the MgO/Al2O3 ratio increases from 0.82 to 1.36. The break point temperature and liquidus temperature of slag initially decrease and subsequently increase. The complex viscous structures are gradually depolymerized to simple structural units. In conclusion, with the increase of MgO/Al2O3 ratio, the degree of polymerization of slag decreases, which improves the fluidity of slag. The variations of liquidus temperature of slag lead to the same changes of break point temperature.

Dry heating treatment (DHT) is a common process widely used in food industry. In this study, the thermodynamic effects of DHT on starch structure and physicochemical properties are investigated. The results show that, with heating temperature increasing during DHT, the molecular size, long-amylose chains with degree of polymerization (DP) ~5000–20,000, and the crystallinity of maize starch are significantly reduced while the granular structure is retained with slightly aggregation between starch particles. The solubility of DHT starch increases from 0.5% to 2%, indicating the majority of DHT starch is still insoluble. DHT affects starch thermal property greatly that, it decreases the gelatinization enthalpy while increases the heterogeneity of starch crystallites. With heating temperature increasing, DHT reduces the overall viscosity of starch paste. The rheological property of DHT starch is frequency-dependent, showing the typical shear thinning behavior and “solid-like” gel property. Especially, as heating temperature reaches 190 °C, the shear resistance becomes stronger, and it is closer to Newtonian fluid. The results prove the thermodynamic effects of DHT on multi-levels of starch structure and physicochemical properties, also indicating the great potential to utilize DHT in modifying starch properties and amplifying its applications.

The formation of hyperbranched polymers (HBPs) generated by the stepwise polymerization of AB2 monomers with the addition of trifunctional core monomers in a continuous-stirred tank reactor, CSTR, was investigated by a kinetic model. The dependency of the degree of polymerization (DP), the degree of branching (DB), and conversion on the Damkohler number (Da) were calculated by a generating function method. When using the polymerization system without the core monomers, the process could be halted due to the production of larger molecules at the conversion of group A, α(A), of approximately 0.44. The addition of core monomers with high reactivity in the CSTR could retard the growth of polymers. Consequently, the reduced weight-average DP and DB could reach 1000 and 0.51, respectively, at a high α(A) of 0.91. Moreover, the amount of unreacted monomers remaining in the flow exiting the CSTR was much less than that without the addition of the core monomers.

The effect of B2O3 content on the rheological behavior and molten structure of the MgO–SiO2-based ferronickel slag were studied at a fixed (SiO2+Al2O3)/(MgO + CaO) mass ratio of 1.4. Results show that the viscosity of the slag melt decreased with the addition of B2O3, and B2O3 had a relatively little effect when its content was over 7 mass%. The break temperature of ferronickel slag reduced from 1711 to 1596 K and its apparent activation energy deceased from 95.34 ± 2.61 to 23.08 ± 1.65 kJ/mol with the addition of B2O3 from 3 to 9 mass%. Structural analyses indicate that B2O3 stripped the oxygen from the silicate structure. The formation of B–O–B structures connected by non-ring [BO3]-trihedral and [BO4]-tetrahedral structural units led to boroxol rings. These resulted in higher degree of polymerization (DOP) of both silicate and borate structures. However, the O− in [BO2O−], the dominant 2D [BO3]-trihedral structure and the formation of asymmetric Si–O–B structural units could depolymerize the network structures of ferronickel slag.

Chitin, mostly extracted from shrimp waste, is the second most abundant biopolysaccharide, next only to cellulose. Enzymatic conversion of chitin into useful bioactive molecules such as chitooligosaccharides (COS) has potential biotechnological applications. The current study describes the characterization of a single modular GH18 chitinase from Chitiniphilus shinanonensis (CsChiL). CsChiL was optimally active at 50 °C in sodium citrate buffer, pH 6.0 and active over a broad pH range (6–10). In addition to hydrolysis, CsChiL displayed chitobiase and transglycosylation activities on COS with degree of polymerization (DP) 2 and 4–6, respectively. CsChiL hydrolyzed chitin polymers (α, β, and colloidal chitin) in a processive manner. Molecular dynamics simulations and residue-wise binding energy contributions provided structural insights and molecular basis of inherent transglycosylation activity by CsChiL. Overall, CsChiL could be useful in generation of COS from the chitin obtained from shrimp waste with potential applications in agriculture and food industries.

Application of thermophilic composting (TC) is limited due to poor efficiency and long composting period. Hyperthermophilic composting (HTC) could effectively overcome this defect. Here, the transformation of humic acid (HA) in both HTC and TC was characterized and compared to investigate the roles of HTC toward accelerating the formation of HA. In HTC, the highest temperature was 96.6 °C, and the hyperthermophilic and thermophilic phases exceed 18 days. The degree of polymerization (DP) in HTC increased to 1.27 on day 27, while it only increased to 1.15 at the end of TC. The elemental composition of the HA in HTC showed higher O atomic content (36.3%) and lower C/N atomic ratio (6.5) compared with TC. These changes indicated that HTC could significantly accelerate oxidized and polycondensed reactions for HA formation, which resulted in the shortening of composting period to 27 days. The maximum fluorescence intensity (Fmax) of humic-like components were achieved faster in HTC (Fmax = 1649.9) than in TC (Fmax = 1316.9), implying that HTC promoted the polycondensation of small molecular components to form HA with larger molecular weight and higher degree of aromatization. Two-dimensional FTIR correlation spectroscopy (2D-FTIR-COS) analysis demonstrated that HTC prevented the HA precursor from condensing before it was deeply oxidized, and increased the content of small molecules rich in carboxyl moieties. Based on the evolution of the molecular structure of HA, the level of oxidation of HA precursors was a key factor to determine the degree of polymerization and the degree of HA humification.

In lignocellulosic biomass biotransformation technology, pretreatment is the most important step to increase the conversion efficiency and reduce cost. The electron beam irradiation (EBI) pretreatment method was discussed in this study. First, the effects of a 0–1200 kGy irradiation dose on saccharification efficiency of lignocellulose biomass (birch) and analytically pure cellulose were studied. Then, the pretreated samples were tested for composition, X-ray diffraction, degree of polymerization, and Fourier transform infrared spectroscopy. Finally, the mechanism of the EBI pretreatment was analyzed from the aspects of lignin content, cellulose crystallinity, cellulose polymerization degree, and cellulose molecular structure. The results show that the EBI pretreatment can significantly improve the efficiency of enzymatic hydrolysis by degrading the lignin in lignocellulose, reducing the crystallinity and polymerization degree of cellulose, and destroying the cellulose molecules. It also obtained that the pretreatment of cellulose and lignocellulose with irradiation has a different trend in enzymatic hydrolysis efficiency with irradiation dose. This indicates that there is a difference in irradiation effects between pure cellulose and lignocellulose. And a possible degradation pathway of cellulose was proposed. This study has important guide for the application and development of EBI pretreatment methods.

Poly (l-lactide)-graft-chondroitin sulfate (PLLA-g-CS) copolymers were synthesized with different l-lactide contents via ring-opening polymerization. Chemical structure of the synthesized copolymers was confirmed by FTIR and HNMR analyses. The degree of polymerization and substitution of PLLA was found to be 0.56 and 2.98, respectively. Nisin was loaded in PLLA-g-CS nanogels at 37 and 42 °C. The hydrodynamic radius of the nanogels was 181 and 399 nm, respectively. The release profile was studied at two different temperatures and pHs over 7 days. The results indicated a variation of the cumulative release of nisin from 25 to 98% depending on the pH and temperature of release media. Cytotoxicity test of nisin loaded nanogels on human dermis fibroblast cells, confirmed no toxic effect. Finally, Antimicrobial activity of the nanogel was evaluated against Staphylococcus aureus and Escherichia coli bacteria. Overall, this study indicated that the dual responsive nanocarrier could potentially be used for infection therapeutic applications.

The economical production of pectin oligosaccharides with a specific degree of polymerization and structure from agro-food waste is an industrially important process. This study identified a novel pectate lyase gene (plhy1) from the thermophilic cellulolytic fungus H. insolens Y1 and tested its ability to produce pectin oligosaccharides. The recombinant PLHY1 produced in Pichia pastoris was superior to other similar enzymes due to its high thermal and pH stability. PLHY1 demonstrated optimal enzymatic activity at 55°C and pH 10.0 in the presence of 0.4 mM Ca2+, and preferred methyl esterified substrates for digestion. High performance anion exchange chromatography-pulsed amperometric detector and ultra high performance liquid chromatography in combination with electrospray ionization tandem mass spectrometry analysis showed that galacturonic acid-oligosaccharides with a small degree of polymerization (4–6) were the major hydrolysates produced by the degradation of apple peel pectin by PLHY1. The properties of PLHY1 make it valuable for application in the agro-food industry for the production of pectin oligosaccharides.

This study investigated the effects of the Al2O3/SiO2 mass ratio and gas composition on the viscosity and structure of Cr-containing CaO-SiO2-MgO-Al2O3-CrOx stainless steel slags. The wet chemical analysis method was used to identify the Cr3+/Cr2+ ratio, and XPS (X-ray photoelectron spectroscopy) and 27Al MAS NMR (magic angle spinning nuclear magnetic resonance) were used to correlate the structural units comprising the melt to the viscosity measurements. The results showed that the break temperature (TBr) corresponded to the temperature when the crystallization fraction increased rapidly. When the Al2O3/SiO2 mass ratio was in the range between 0.125 and 1.0, the viscosity gradually increased as the Al2O3/SiO2 mass ratio increased. Similar viscosity trends were observed for gas compositions with higher oxygen partial pressures, which was correlated to an increased degree of polymerization (DOP) of the slag structure. In addition, the variation in the Cr3+/Cr2+ ratio, which decreased with increasing Al2O3/SiO2 mass ratios and increased with higher oxygen partial pressures, correlated well with the viscous behavior of the slags, the variation trends of [AlO4]- and [AlO5]-structural units, and the increased DOP of the slags.

Poly(ionic liquid)s brush-grafted carbon dots (CDs-PILs-X) were synthesized for the first time by surface-initiated atom transfer radical polymerization, where X representing polymerization time was 1, 3, 6, 12, and 18 h. Their tribological properties as lubricant additives of polyethylene glycol (PEG200) were evaluated under the steel/steel contact and linear reciprocating mode. The CDs-PILs-1 exhibited the best friction-reducing and antiwear performance at a concentration (c) of 1.5 wt%. Specifically, the friction coefficient and wear volume of PEG200 were reduced by 61.9% and 82.5%, respectively. At a concentration (c) of 1.5 wt%, the performance of CDs-PILs-1 apparently outperformed that of PILs-1, reflecting the particularly important role of carbon cores in boundary lubrication. In addition, the CDs-PILs-1 was comparable to CDs-PILs-3 and much superior to CDs-PILs-6-18, suggesting that the carbon cores and PILs shells of CDs-PILs played a synergistic lubrication effect and an optimal degree of polymerization of 3.0 (close to that of CDs-PILs-1) should exist. Wear scar surface analyses revealed that robust boundary tribofilms with a thickness of approximately 190 nm, that is, the tribochemical film embedded with carbon cores, were formed on the sliding surfaces lubricated by CDs-PILs-1 dispersion, directly accounting for the excellent tribological properties of CDs-PILs-1.

The reaction of Zn[N(SiMe3)2]2 with N-alkyl-N-[ω- (pentafluorophenylamino)alkyl]-N-[2-(pentafluorophenylamino) ethyl]amines afforded new bicyclic zinc complexes. The complexes initiate ring-opening polymerization of ɛ-caprolactone and trimethylene carbonate to give the corresponding polymers with high molecular weight and satisfactory degree of polymerization.

Synthesis possibility of cellulose sulfates with a low and high degree of substitution (DS) by direct homogenous sulfation of cotton cellulose in N,N-dimethylacetamide/lithium chloride (DMA/LiCl) using SO3/pyridine (Py) complex was studied comprehensively. The sulfation reactions were carried at different temperatures, time durations, amount of the sulfating reagent and celluloses with varying weight average degree of polymerization (DPw). It was found that the method is very appropriate to prepare sodium cellulose sulfate (SCS) with low and high DS from celluloses having wide range DPw. Completely water-soluble SCS samples with regulable DS values from 0.23 to 2.56 were obtained. Suitable conditions were proposed to gain high sulfate content and the samples with DS values of 2.16–2.32, and yield of 69.4–77.8% could be prepared in these conditions. Celluloses with low and high DPw values exhibited similar reactivity for sulfation. Precipitation of the product and drastic depolymerization in the polymer chain have not occurred during the reaction.

Procyanidins (PCs) are polyphenols highly accumulated in litchi fruit (Litchi chinensis). Despite their bioactivity, the molecular composition of native and oxidized procyanidins is little understood. In this paper, polyphenols from litchi pericarp were extracted using two solvents (methanol and acetone). The mean degree of polymerization (mDP) of native and identification of oxidized PCs were carried out by phloroglucinolysis– and thioglycolysis–HPLC–ESI–MS/MS, respectively. About 60% of extracted polyphenols corresponded to procyanidins from litchi pericarp. Native PCs were mainly oligomeric procyanidins (mDP 4). Only (−)-epicatechin was detected as terminal and extension units in PCs. Thioglycolysis–HPLC–ESI–MS identified five oxidation markers of PCs with [M−H]− m/z 575, 593, 609, 679 and 863. Intra- and intermolecular modifications of A and B-type procyanidins were identified. The method used for the characterization of PCs from litchi pericarp allowed understanding of the structural composition of its native and oxidized tannins.

To characterize the interactions of banana condensed tannins (BCT) with copper (Cu2+), zinc (Zn2+) and iron ions (Fe2+), various methods and techniques were utilized in the current work. Our findings indicated that BCT isolated from green bananas (cv. Brazil) were a mixture of flavan-3-ol oligomers with degree of polymerization in the range of 3–5 and with the trimers as the main component. The (−)-epigallocatechin and (−)-epicatechin were the dominant units of oligomer structures. BCT could interact with divalent transition metal ions mainly via catechol group-ion exchange and pyrogallol group-ion exchange, while static quenching mechanism was the main action mode of BCT fluorescence quenching by metal ions. The effectiveness of precipitation of metal ions by BCT decreased with the order of Fe2+ > Cu2+ > Zn2+. Alternatively, the characteristics of BCT-metal ion coprecipitates confirmed the interactions between BCT and divalent metal ions. Therefore, characterization of the interaction mechanisms between BCT and biologically important metal ions should help in the design of strategies to prevent the metal-induced toxicity in individuals with a high exposure of transition metal ions.

A family of amphiphilic diblock copolymers poly(lauryl methacrylate)-poly(N-(2-methacryloylxyethyl)pyrrolidone) (PLMA-PNMP) were developed by the reversible addition-fragmentation chain transfer (RAFT) solution polymerization method. The self-assembly behaviors of developed copolymers in the selective solvent, n-dodecane, were studied in detail by employing static light scattering, dynamic light scattering, transmission electron microscopy and rheology measurements, and the structure-property relationship of them was also established accordingly. It was noticed that the morphologies of formed aggregates were affected by temperature apparently because of the glass transition temperature (Tg) of PNMP segments. Generally speaking, spherical micelles, cylindrical micelles and vesicles were gradually formed upon increasing the degree of polymerization (DP) of PNMP segment at the constant DP of PLMA above Tg. However, nanoparticles with particular morphologies would be formed below Tg because of the Tg-induced solidification of PNMP core, resulting in apparent temperature-induced sol-gel transitions. For example, spherical micelles were formed spontaneously in 15 wt% PLMA19-PNMP39 solution at 85 °C, whereas nanoparticles with wormlike morphology were formed at 25 °C instead. The present work not only established the structure-property relationship of PLMA-PNMP copolymers, but also contributes to understand the nature of polymerization-induced self-assembly as well.

The Dissipative Particle Dynamics (DPD) simulation technique was used to elucidate the composition-dependent equilibrium morphological behavior of three different symmetric ABA triblock copolymers, which were; poly(e-caprolactone)-poly(dimethylsiloxane)-poly(e-caprolactone) (PCL-PDMS-PCL), poly(e-caprolactone)-poly(ethylene oxide)-poly(e-caprolactone) (PCL-PEO-PCL) and poly(L-lactide)-poly(dimethylsiloxane)-poly(L-lactide) (PLLA-PDMS-PLLA). These polymers were chosen due to their biomedical and biotechnological importance. Polymeric A and B blocks were modeled as connected chain of beads with varying incompatibility. The impact of the block incompatibilities on the microphase separation as well as on the equilibrium phase behaviors were investigated at the mesoscopic scale. A detailed visual analysis of the DPD images and constructed phase diagram showed that quite different equilibrium morphologies were attainable by controlling the molecular weights of the blocks and the strength of the intermolecular interaction between them. More compatible A and B blocks underwent lamellar to cylindrical and cylindrical to spherical phase transitions at lower B block concentrations. Our results clearly showed that, Flory–Huggins interaction parameter (χ) and degree of polymerization (N) were the only control parameters, which determined the shape and size of the phase domains, as well as the extent of equilibrium nanophase separation. Our DPD simulated morphologies were compared with experimental images obtained by Atomic Force Microscopy (AFM).

Vesicles have been attracting a great deal of interest because of their great potential for health food, medicine, and biotechnology applications. This study aimed to develop a new type of debranched starch (DBS) vesicle for loading and delivering active components. DBS with a low degree of polymerization (6.75) and good water solubility was modified with octenyl succinic anhydride (OSA) to obtain an amphiphilic polymer. Both the Fourier transform infrared spectroscopy and the 1H nuclear magnetic resonance results confirmed the successful synthesis of amphiphilic OSA-DBS polymers. The OSA-DBS spontaneously formed 10–30 nm vesicles in a water system, as measured by transmission electron microscopy. The vesicles were relatively stable at different temperatures, pH values, and ionic strengths. Insulin was used as a hydrophilic functional ingredient model. The insulin-loaded vesicles exhibited a high loading content (∼13.36%). These OSA-DBS vesicles have potential utility as advanced carriers in the health food and biomedical industries.

Polysialic acid (polySia) is widely investigated in various biopharmaceutical applications (e.g. treatment of inflammatory neurodegenerative diseases), whereby a certain polySia chain length with an average degree of polymerization 20 (polySia avDP20) shows most promising effects. In this study, a rapid analytical method using a HPLC and charged aerosol detector (CAD) for the direct chain length characterization of biopharmaceutically relevant polySia was developed. It was evaluated as a fast alternative to the commonly used 1,2-diamino-4,5-methylenedioxybenzene (DMB) HPLC application. In contrast to HPLC-FLD, the CAD-application provides the actual chain length of polySia within ∼3 h. The reliability of the HPLC-CAD was evaluated with a commercial reference sample of known chain length and biotechnologically produced LC polySia (long chain polySia with a DP ∼130). Moreover, HPLC-CAD was successfully applied in the direct detection of oligo- and polySia until DP ∼65 and can be used to monitor the thermal hydrolysis and subsequent chromatographic isolation of polySia avDP20 (average degree of polymerization 20) without DMB sample derivatization. In addition, CAD was successfully applied for polySia quantification using a modified elution gradient. It was tested as a fast alternative to commonly used thiobarbituric acid (TBA) assay. A differentiation between LC polySia and smaller, hydrolysed polySia chains was intended and possible. For LC polySia and polySia avDP20, a quadratic relation between polySia mass-concentration and CAD signal was observed. In case of LC polySia, a quadratic dependency with a determination coefficient of R2 = 0.99 in a broad concentration range between 0.025 and 15 mg mL−1 was determined. Quantification of polySia avDP20 was found to have quadratic dependency with a determination coefficient of R2 = 0.99 in a concentration range between 0.02 and 0.25 mg mL−1. The HPLC-CAD was tested for quantification with polySia references of known concentration and showed high accordance with a concentration deviation ≤6.7%. The CAD quantification method was also applied in the polySia avDP20 production process and was compared to the TBA assay. Results of a correlation plot showed a high determination coefficient of R2 = 0.98. Overall, HPLC-CAD analysis was successfully tested as a suitable characterization and quantification application in the biopharmaceutical production of polySia.

Five gelatinized jackfruit starches (GJFSS: M1', M5', M6', M11', and BD') were prepared using amylose mixed with five types of amylopectin. M1' had the lowest degree of polymerization while BD' had the highest. The five GJFSS samples showed significant variations in microstructures, varying from a compact structure (M1') to a loose structure (BD'). The freeze-thaw stability was consistent with results of the microstructure. High syneresis formed compact structure (M1'), and low syneresis formed a loose structure (BD'). As the degree of polymerization of amylopectin increased, the gelatinization enthalpy, peak viscosity, breakdown, final viscosity, setback, and absorbance ratio decreased, while the transition temperature and pasting temperature increased. The thermal, pasting properties, and the short-range molecular order, were consistent with the results of the microstructure and syneresis. All the results indicated that the degree of polymerization of amylopectin is an important structural factor that can significantly affect the gelatinization properties of starch.

The fast pyrolysis mechanism of xylose, xylobiose and xylan was investigated with combined fast pyrolysis experiments and quantum chemistry calculations. The results indicate that acyclic d -xylose is an important intermediate for the formation of the major pyrolytic products in xylose pyrolysis, i.e., 1,4-anhydro- d -xylopyranose (ADX), furfural (FF) and hydroxyacetaldehyde (HAA). ADX derives from the successive cyclization of d -xylose which is the only source for ADX formation. 3-Deoxy-xylose is the most important intermediate for FF formation. HAA results from the C C bond scission by retro-aldol and cyclic Grob fragment. In addition, the five-membered intermediate derived from the ring-contraction reaction can transform into FF with high selectivity. The dehydrated xylose is also another source for HAA formation. The fast pyrolysis mechanism of xylobiose is similar to that of xylose, and thus similar pyrolytic product distribution can be obtained from them. However, the pyrolytic products of xylan differ significantly from those of xylose and xylobiose, which is ascribed to its high degree of polymerization and the branches in it.

Well-controlled polystyrene-polymethacrylate bottlebrush block copolymers (BBCPs) of ultrahigh molecular weight using ω-end-norbornyl polystyrene as the macromonomer for the first block were synthesized by combining living anionic polymerization (LAP) and ring-opening metathesis polymerization (ROMP). The ω-end-norbornyl polystyrene (NB-PSt), poly(tert-butyl methacrylate) (NB-PtBMA), poly(methyl methacrylate) (NB-PMMA), and poly(benzyl methacrylate) (NB-PBzMA) macromonomers (MMs) were synthesized by the LAP. The ROMP of the MMs led to poly(NB-g-St) (molecular weight, Mn = 1515 kDa, and dispersity, Ð = 1.12), poly(NB-g-tBMA) (Mn = 1470 kDa, Ð = 1.49), poly(NB-g-MMA) (Mn = 1128 kDa, Ð = 1.42), and poly(NB-g-BzMA) (Mn = 941 kDa, Ð = 1.16) bottlebrush homopolymers at degree of polymerization (DP) of 500. Synthesis of the BBCP, P(NB-g-St)-b-P(NB-g-tBMA) was well-controlled with high molecular weight and a low dispersity (Mn = 3002 kDa, Ð = 1.17) with a total DP of 976. The self-assembly of the resulting BBCP films revealed periodic lamellar morphologies with characteristic photonic crystal properties.

Starch, one of the most important components of coarse grains, has received widespread attention because of its prominent potential health benefits. In the present study, we isolated starches from the grains of sorghum, tartary buckwheat, common buckwheat, mungbean, and pea and studied their structural and physicochemical properties. These five starches all showed the distinctive “Maltese cross” effect (birefringence) but significantly differed in morphology, size, and complexity of granules. Sorghum starch exhibited the lowest amylose content and highest weight-average molar mass. Mungbean contained more short amylopectin [degree of polymerization (DP) 6–12 = 23.4%]. Pea starch exhibited the highest amylose content, highest amylopectin average chain length, and lowest weight-average molar mass. The starches of sorghum, tartary buckwheat, and common buckwheat showed A-type crystallinity, whereas those of mungbean and pea showed C-type crystallinity. Our results provide useful information for the application of coarse grain starches in diverse industries.

In this review, structure-property trends are systematically analyzed for four amphiphilic properties of sugar-based surfactants: critical micelle concentration (CMC), its associated surface tension (γCMC), efficiency (pC20) and Krafft temperature (TK). First, the impact on amphiphilic properties of the alkyl chain size and the presence of branching and/or unsaturation is investigated. Then, various polar head parameters are explored, such as the degree of polymerization of the sugar unit (mono- or oligosaccharides), the chemical nature of the linker and the sugar configuration. Some systematic comparisons between ethoxylated surfactants and sugar-based surfactants are also carried out. While some structural trends with the impact of alkyl chain length or the polar head size are now well understood, this analysis points out that systematic studies of more specific effects of alkyl chain (e.g. branching, unsaturation, presence of rings, position on the polar head) and polar head (e.g. linker, anomeric configuration, internal stereochemistry, cyclic vs. acyclic sugar residues) were scarcer or not available to date. This work encourages the use of these structural trends in the perspective of developing new bio-based surfactants and their consideration in predictive models. It also highlights the need of further experimental tests to fill remaining gaps notably to explore some specific structural features (such as the introduction of rings in the alkyl chain or the position of the alkyl chain on the polar head) and towards applicative properties (like foaming capacity or wettability).

CaO-SiO2-Al2O3-MgO (CSAM) system is a fundamental and significant system in geology, metallurgy and the glass industry. Herein, we firstly investigated the roles of minor elements on the microstructures of this system. By Raman spectra and deconvolutions, we found that the presence of B2O3 induced an increase of the degree of polymerization (DOP) of the networks. On the contrary, the existence of Na2O, K2O and MnO had an opposite effect, i.e., the average number of bridging oxygen per Si atom decreased by 0.20, 0.07 and 0.11, respectively, with ~5 wt% of additions. Moreover, two particular minor elements, CaF2 and CaS, resulted in a decrease of the DOP. Furthermore, the macroproperties of this CSAM system with various minor elements were connected to the present microstructural analysis and thus the micro-macro relationship was deeply discussed, based on which we elucidated the clues for modifying this system in different levels using these minor elements.

Cellulose amorphization is a suitable process that allows greater accessibility of cellulolytic enzymes to glycosidic bonds of cellulose, thus improving the yield of bioethanol obtained from lignocellulosic biomass. In a theoretical framework, we demonstrated the amorphization process of two cellulose allomorphs (Iα, Iβ) using a new Molecular Dynamics (MD) protocol at high temperatures. At 700 K, in the high-temperature molten phase, these allomorphs showed the formation of structures with quite amorphous-shell and slightly paracrystalline-core (Am-Par structures) when the degree of polymerization is increased. Applying different characterization methods, we confirmed that Am-Par structures were similar at 700 K, as well as over a temperature ranging from 680 K to 380 K. This confirmation was based on low density of intra-chain hydrogen bonds (HBs), the absence of bands in the region of 3330–3470 cm−1 corresponding to such HBs in the simulated IR, low values of the lateral order index calculated from IR, Q4 and Q6 values close to zero, loss of long-range ordering observed in radial distribution functions, total destruction of crystal unit cell corroborated by X-ray diffraction, and similarity between probability density distribution of dihedral angle ψ with that computed for completely amorphous cellulose. Nonetheless, as revealed by X-ray diffraction results, this protocol seems to provide more crystalline structures starting from cellulose microfibrils having a polymerization degree higher than 10.

Monodisperse gold nanoparticles (GNPs) were synthesized in a water-in-oil emulsion system (reverse micelles) composed of 80% N-methylmorpholine N-oxide (NMMO)/20% H2O and dodecane, stabilized with an anionic surfactant: bis(2-ethylhexyl)sulfosuccinate sodium salt. Cellooligomers with a degree of polymerization of 6 or 15 (βGlc6 or βGlc15, respectively), which were labeled at each reducing end group with thiosemicarbazide (TSC) and dissolved in the aqueous NMMO phase, were successfully conjugated to the surfaces of GNPs in situ during spontaneous NMMO-mediated gold reduction. As-synthesized βGlc6-GNPs and βGlc15-GNPs had average diameters of 11.3 ± 2.1 and 10.5 ± 0.7 nm, respectively, while their surface sugar densities were 0.21 and 0.51 chains nm–2, respectively. Concanavalin A (ConA), a lectin that recognizes non-reducing end groups of glucose residues, aggregated with βGlc15-GNPs with higher sensitivity than it did with βGlc6-GNPs, possibly as a result of the sugar density on the GNP surfaces. The aggregates were rapidly re-suspended by adding methyl-β- d -glucopyranoside as a binding inhibitor. Other lectins and proteins showed no interaction with βGlc-GNPs. Therefore, clustering of glucose non-reducing ends on the GNP surfaces via strong intermolecular association of cellooligomers, possibly led to high affinity for ConA. This facile synthesis route to structural carbohydrate-decorated GNPs has potential applications in carbohydrate–nanometal conjugate nano-biosensor development.

Polythiophene (PTh) was synthesized by a standard chemical oxidation procedure by using Ferric chloride (FeCl3) as an oxidizer without any post doping process. The synthesis procedure was optimized by varying different parameters like reaction temperature, monomer to oxidizer ratio, solvent system, reaction time and oxidizer addition time to realize the maximum electrical conductivity and without compromising on product yield. In the optimized synthesis procedure, highest yield of 80% with a maximum electrical conductivity of 9 Scm−1 was achieved. These results are first of its kind in the literature reported so far for the similar conditions. The enhancement of electrical conductivity was attributed to the increase in the degree of polymerization under the optimized reaction conditions and was substantiated with UV–Vis, Diffuse Reflectance Spectroscopy (DRS), FTIR, NMR solid state, SEM, XRD and DSC studies. This paper is the first of its kind to report the room temperature synthesis procedure of PTh with highest electrical conductivity and yield.

Mannose polymers are important non-starch polysaccharides in beers. In this study, thirty-six beer samples representing three categories based on materials, including all barley malt beer, barley malt with adjuncts beer and wheat beer, were selected to investigate the content as well as its correlation with beer physicochemical indices, degree of polymerization, molecular weight and existent form of mannose polymers. The results suggested that mannose polymers level was significantly high in the wheat beer (156.76 mg/L and 456.50 mg/L calculated as mannan and glucomannan, respectively). Degree of polymerization was 23–47 and 46–162 calculated as mannan and glucomannan, and the molecular weight was 3,744 - 7,632 Da and 7,470 - 26,262 Da, respectively. Average ratio of glucose to mannose in glucomannan was between 1.79 and 1.93 without significant difference among three groups. Mannose polymers possibly exist in mannan, glucomannan or both. The content had significantly positive correlation with the original extract and viscosity of beers. Their correlation coefficients indicated more important influence on beer viscosity than β-glucan. This preliminary study would be helpful for revealing the structure of mannose polymers and its effect on beer brewing as well as human health.

The aim of this study was to understand estolide enzyme polymerization from free ricinoleic acid (FRA) and its lubricant properties, by controlling the reaction time, during the course of a reaction involving a two-step enzymatic hydroesterification from castor oil. Adding water increased the reaction rate, reducing the total acidity to 30% in 24 h. FRA is the major component of castor oil (up to 90%). A GC analysis of the FRA, expressed as g/100 g of sample, was used to determine the FRA profile during estolide polymerization. These data suggested a relationship between the total acidity of the samples and the FRA concentration. The estolide profile and number (EN) were determined by GPC and NMR analyses. A 14-hour reaction time was needed for total consumption of FRA, with an EN of 5.5 and a degree of polymerization of the major estolide of 6/7. The analysis showed that estolides of several sizes [dimers, trimers, tetramers, and pentamers (+)] were produced during the reaction; between 8 and 14 h the EN grew exponentially until reaching a plateau after about 16 h of reaction. From 14 to 24 h, although the estolide-size profile did not change significantly, EN continued to increase with increasing reaction time, until a polymerization degree of 7/8 at 24 h. The increase in EN corresponds to the increase in the viscosity index and oxidative stability, reaching 164 and 43 min, respectively, after 20 h of reaction; as well as to the decrease in pour point and total acidity number, which reached −48 °C and 36.8 mg KOH/g of sample after 20 h of reaction. This is the first description of a kinetic method to control the degree of estolide polymerization, by controlling the reaction time; and of its relationship between the EN and the lubricant properties of these molecules, aiming toward the production of different biolubricants for several applications and desired uses.

Microwave, electronic pressure cooking (EPC), and water absorption method are the common but different ways used for cooking rice. To explore mechanisms for effects of cooking methods on rice stickiness, starch leaching behaviour and the fine structure of leached starch are investigated. We find: (i) EPC improves starch leaching, i.e. the highest amount for total solids and leached amylopectin (AP), while microwave restricts starch leaching; (ii) the chain-length distributions (CLDs) of leached AP between rice samples are similar while CLDs of leached amylose (AM) are mainly ranged between degree of polymerization (DP) 100 and 1000; (iii) microwave makes rice leaching more long-AM chains with DP 1000-10,000; (iv) the varied stickiness of differently cooked rice are mainly caused by total amount of leached materials, especially leached AP, rather than the molecular structure of leached starch. This mechanism explanation provides better view towards helping consumers improve cooking and eating quality of cooked rice.

The most common negative influences on lignocellulosic materials from biological point of view include invading of microorganisms, which have in humid environments of porous materials favourable conditions for growth and reproduction. The aim of this study was to assess the influence of selected compounds present in essential oils- EOs (linalyl acetate-LA and citral-C) and the accelerated ageing process on the chemical (cellulose degree of polymerization, content of saccharides), mechanical (tensile index) and physical (fibres length distribution) properties of papers. LA and C were evaluated as the compounds with the highest antimicrobial activity and therefore, they were applied into the paper mass in form of their vapours. Paper samples were prepared from five types of material. Chemical changes were evaluated by wet chemical methods, size exclusion chromatography and high performance liquid chromatography, mechanical property according to ISO 1924-2 standard and morphological properties of fibres by using Fiber Tester equipment. In the view of followed properties, the protecting impact of these EOs efficient compounds has a greater importance in their application before the ageing process itself, especially at wood pulp papers and papers produced from sulphate deciduous pulp. The contents of both holocellulose and a cellulose degree of polymerization were significantly correlated with the tensile index of the paper.

The frequently studied polysaccharide, chitosan oligosaccharide/chitooligosaccharide (COS) is the major degradation product of chitosan/chitin via chemical hydrolysis or enzymatic degradation involving deacetylation and depolymerization processes. Innumerable studies have revealed in the recent decade that COS has various promising biomedical implications in the past analysis, current developments and potential applications in a biomedical, pharmaceutical and agricultural sector. Innovations into COS derivatization has broadened its application in cosmeceutical and nutraceutical productions as well as in water treatment and environmental safety. In relation to its parent biomaterials and other available polysaccharides, COS has low molecular weight (Mw), higher degree of deacetylation (DD), higher degree of polymerization (DP), less viscous and complete water solubility, which endowed it with significant biological properties like antimicrobial, antioxidant, anti-inflammatory and antihypertensive, as well as drug/DNA delivery ability. In addition, it is also revealed to exhibit antidiabetic, anti-obesity, anti-HIV-1, anti-Alzheimer's disease, hypocholesterolemic, calcium absorption and hemostatic effects. Furthermore, COS is shown to have higher cellular transduction and completely absorbable via intestinal epithelium due to its cationic sphere exposed on the more exposed shorter N-glucosamine (N-Glc) units. This paper narrates the recent developments in COS biomedical applications while paying considerable attention to its physicochemical properties and its chemical composition. Its pharmacokinetic aspects are also briefly discussed while highlighting potential overdose or lethal dosing. In addition, due to its multiple NGlc unit composition and vulnerability to degradation, its safety is given significant attention. Finally, a suggestion is made for extensive study on COS anti-HIV effects with well-refined batches.

In entrained flow gasifier, slag properties such as melting and viscosity of molten slag are critical for continuous operation. Molten coal slag belongs to silicate-containing melts and slag behaviors are intrinsically determined by the microstructure transformation. Calcium is believed as an effective ingredient to decrease viscosity as well as reduce the polymerization degree. The structure of coal slags with different calcium ranging from 10% to 25% is investigated by solid-state nuclear magnetic resonance (SS-NMR) and molecular dynamics (MD). 29Si, 27Al spectra were obtained through quenching slags under 1873 K and the distributions of Qn species are analyzed. For simulation part, the radial distribution function, the proportion of bridge oxygen (Ob) and non-bridge oxygen (Onb) as well as the distributions of Qn species were calculated. Both NMR experiment and MD simulation show that increase of CaO can lead to a reduced degree of polymerization. The Ca ions enter into the network formed by Si and Al tetrahedral and bond with oxygen ions, which weakens the network stability. Consequently, the proportion of non-bridge oxygen increases and complex network unit-Q4 breaks into smaller units such as Q3, Q2, Q1, reducing the polymeric network. The depolymerization effect of CaO can explain the change of slag properties such as viscosity or melting temperature.

In this study corms from Trimezia juncifolia were collected in the wet (WSS) and dry (DSS) seasons and used for extraction of starch. Results evidenced that drought stress interfered with the yield, morphological and physicochemical properties of the starches. In addition, it was observed a higher content of amylose for DSS (44%) when compared with WSS (41%). Drought stress did not interfere with the degree of polymerization (DP) of amylopectin, whereas decreased the amylose DP for DSS. Also, starch granules changed from A-type polymorph in the DSS to a CC-type in WSS. Drought stress reduced the starch crystallinity from 27% in WSS to 25.9% in DSS. In addition, the endothermic transition temperatures and enthalpy change of transition were also affected by drought stress. Finally, results clearly demonstrate that changes in the morphological and physicochemical properties of the starch granules figure as adaptive strategies of T. junciolia to drought stress.

An investigation had been conducted to study the effect of CaO/SiO2 mass ratio and B2O3 on the crystallization behavior and the melt structure of fluorine-free mold fluxes. The results showed that the increase of CaO/SiO2 ratio tends to promote the crystallization behavior of the fluorine-free mold flux system, due to the depolymerization of the original complex borosilicate structure by the released free oxygen (O2−) ions with the added CaO. Small amount of B2O3 would initially inhibit the mold flux crystallization, then the further addition would promote crystallization. The melt structure analysis results suggested that with the addition of B2O3 content, the existing silicate structure would connect with each other and also link with the dissociative [BO3]-trihedral units to form borosilicate chain. Simultaneously, O2– could destroy the original diborate structure and form two simple borate structures. Subsequently, the simple borate structure would connect with the dissociative [BO3]-trihedral and the formed borosilicate chain to form a more complex borosilicate structure. Thus, the degree of polymerization of whole molten slag was getting improved, but the overall effect on the mold flux crystallization was depended on the balance between the molten slag structure and viscosity, in which 6 mass% was the critical point in the current mold flux system.

Polyurethane (PU) di-block copolymers are one of the most versatile polymeric materials, comprised of hard and soft segments that contribute to PU's broad range of applications. Polybutylene adipate (PBA) is a commonly used soft segment in PU systems. Characterizing the structure of PBA polymers is essential to understanding complex heterogeneity within a PU sample. In this study, ion mobility-mass spectrometry (IM-MS) and tandem mass spectrometry (MS/MS) are used to structurally characterize a PBA standard (Mn = 2250) adducted with a combination of monovalent alkali cations (Li, Na, K, Rb, and Cs). IM-MS profiles show unique trends associated with each cation-adducted PBA sample. Charge state trends: +1, +2, and +3 were extracted for cation-adducted PBA oligomers, and investigated to study gas-phase transitional folding. To quantitatively assess the gas-phase structural similarities and differences, a statistical test (ANOVA) was used to compare PBA oligomer-cation collisional cross sections (CCS). Fragmentation studies (MS/MS) identified the unique behavior of Li and Na for promoting 1,5 H-shift and 1,3 H-shift fragmentation, whereas the PBA precursor preferentially loses the larger K, Rb, and Cs cations as the ion activation energy is increased. The combination of adducted alkali cations, IM-MS, and MS/MS allow for unique structural characterization of this important PBA system.