Effect of Methanol on Formation of Levulinates from Cellulosic Biomass

Levulinates (methyl levulinate and levulinic acid) were produced from cellulose and eucalyptus wood chips in water and/or methanol solution under acid catalysis. In water, only levulinic acid was formed, and its yield was 49–54 mol % of the glucan in biomass or about half of the glucan was wasted forming byproducts including insoluble humins. In a 90 vol % methanol solution, methyl levulinate was the main product, and the yield of levulinates reached 66 mol %. Protecting glucose from humins formation by quick conversion into methyl glucosides was found to be the key to a high yield of levulinates. Methanol had little effect on formation of humins and levulinates from 5-hydroxymethylfurfural. In addition to the main reactions with glucose, 5-hydroxymethylfurfural, and levulinic acid, methanol was also consumed in other reactions that caused a substantial loss of methanol and presented a technical challenge to using methanol in biomass refining

Kinetic Analysis on Deactivation of a Solid Brønsted Acid Catalyst in Conversion of Sucrose to Levulinic Acid

A solid Brønsted acid (Amberlyst-36) was used as a catalyst in the formation of levulinic acid from sucrose in aqueous solutions. Its rapid deactivation was investigated and simulated. Two major catalyst deactivation mechanisms were identified: (a) loss of protons due to ion exchange with cations and (b) blocking of the catalyst surface or active sites by byproducts. The catalyst activity declined with the accumulation of the byproducts, whereas the effect of ion exchange was quite complicated. The catalyst actually exhibited an increased activity with a small extent of ion exchange, because the free protons had a higher activity than those associated with the solid matrix. In repeated use, however, the solid catalyst lost most protons and activity. A first-order kinetic model was modified to characterize the deactivation mechanisms that provides a good simulation of the complicated performance of the solid catalyst in sugar solutions

Effect of Glass Fibers with Different Surface Properties on the Morphology and Properties of Polyamide 6/Poly(butylene terephthalate) Blends

The morphology and properties of polyamide 6 (PA6)/poly­(butylene terephthalate) (PBT) blends filled by three types of glass fibers (GF) with different surface properties were investigated. The GF were unmodified or surface-modified for PA6 or PBT, denoted as GF­(Pris), GF­(PA6), and GF­(PBT), respectively. The incorporation of 15 wt % of GF with different surface properties all led to a transition from a cocontinuous (at least a part of each phase penetrates the whole volume in a coherent and continuous manner) to a sea-island (separated domains dispersed in a continuous matrix) morphology with PA6 being the matrix phase when PA6/PBT equaled 45/55. GF­(Pris) was always encapsulated by PA6, while the encapsulating layers on the surfaces of GF­(PA6) and GF­(PBT) changed from PBT to PA6 with increasing PA6 contents. The morphological changes induced by GF caused more PBT to crystallize at a lower temperature and enhanced the alkali tolerance of the blend significantly

Effect of Glass Fibers with Different Surface Properties on the Morphology and Properties of Polyamide 6/Poly(butylene terephthalate) Blends

The morphology and properties of polyamide 6 (PA6)/poly­(butylene terephthalate) (PBT) blends filled by three types of glass fibers (GF) with different surface properties were investigated. The GF were unmodified or surface-modified for PA6 or PBT, denoted as GF­(Pris), GF­(PA6), and GF­(PBT), respectively. The incorporation of 15 wt % of GF with different surface properties all led to a transition from a cocontinuous (at least a part of each phase penetrates the whole volume in a coherent and continuous manner) to a sea-island (separated domains dispersed in a continuous matrix) morphology with PA6 being the matrix phase when PA6/PBT equaled 45/55. GF­(Pris) was always encapsulated by PA6, while the encapsulating layers on the surfaces of GF­(PA6) and GF­(PBT) changed from PBT to PA6 with increasing PA6 contents. The morphological changes induced by GF caused more PBT to crystallize at a lower temperature and enhanced the alkali tolerance of the blend significantly

Effect of Glass Fibers with Different Surface Properties on the Morphology and Properties of Polyamide 6/Poly(butylene terephthalate) Blends

The morphology and properties of polyamide 6 (PA6)/poly­(butylene terephthalate) (PBT) blends filled by three types of glass fibers (GF) with different surface properties were investigated. The GF were unmodified or surface-modified for PA6 or PBT, denoted as GF­(Pris), GF­(PA6), and GF­(PBT), respectively. The incorporation of 15 wt % of GF with different surface properties all led to a transition from a cocontinuous (at least a part of each phase penetrates the whole volume in a coherent and continuous manner) to a sea-island (separated domains dispersed in a continuous matrix) morphology with PA6 being the matrix phase when PA6/PBT equaled 45/55. GF­(Pris) was always encapsulated by PA6, while the encapsulating layers on the surfaces of GF­(PA6) and GF­(PBT) changed from PBT to PA6 with increasing PA6 contents. The morphological changes induced by GF caused more PBT to crystallize at a lower temperature and enhanced the alkali tolerance of the blend significantly

Serum CEACAM1 Level Is Associated with Diagnosis and Prognosis in Patients with Osteosarcoma

<div><p>Carcinoembryonic antigen related cell adhesion molecule 1 (CEACAM1) is a trans-membrane multifunctional cell adhesion molecule associated with tumor cell proliferation, apoptosis, angiogenesis, invasion, and migration during tumor development. In the present study, we evaluated serum CEACAM1 level in osteosarcoma patients to explore its diagnostic and prognostic value for this particular malignancy. Sera from 113 patients with primary osteosarcoma, 98 patients with benign bone tumors and 126 healthy controls were obtained. Serum CEACAM1 level was measured with ELISA and correlation with clinicopathological characteristics was further analyzed. Receiver operating curves (ROC), Kaplan-Meier curves, and log-rank analyses as well as Cox proportional hazard models were used to evaluate diagnostic and prognostic significance. The results revealed that serum CEACAM1 level was significantly higher in osteosarcoma patients compared to benign bone tumors and healthy controls (455.2 ± 179.9 vs 287.4 ± 103.2, 260.8 ± 109.7 pg/ml, respectively). Osteosarcoma patients with larger tumors, later-tumor stages, low tumor grades, and distant metastases had much higher CEACAM1 compared to those with smaller tumors, earlier tumor stages, high tumor grades and non-distant metastases (P < 0.05 for all). Multivariate logistic regression analysis confirmed that high serum CEACAM1 level was an independent risk factor for distant metastases (OR = 3.02, 95%CI 1.65–4.17). To distinguish osteosarcoma patients from those with benign bone tumor and healthy controls, ROC/AUC analysis indicated an AUC of 0.81 (sensitivity 0.61; specificity 0.89) and an AUC of 0.77 (sensitivity 0.57; specificity 0.92), respectively. Osteosarcoma patients with higher CEACAM1 had relatively lower survival compared to those with low CEACAM1 (P < 0.01), and multivariate analyses for overall survival revealed that high serum CEACAM1 level was an independent prognostic factor for osteosarcoma (HR = 1.56, 95%CI 1.23–3.28). The present study suggested that elevated serum CEACAM1 level might be a novel diagnostic and prognostic biomarker for osteosarcoma patients.</p></div

Oil/Water Separation Performances of Superhydrophobic and Superoleophilic Sponges

Superhydrophobic and superoleophilic sponges were fabricated by immersion in an ethanol solution of octadecyltrichlorosilane. The resulting coating strongly adheres to the sponges after curing at 45 °C for 24 h. Absorption capacities of 42–68 times the polymerized octadecylsiloxane sponge weight were obtained for toluene, light petroleum, and methylsilicone oil. These adsorption capacities were maintained after 50 cycles

A Novel Cellulose/Ionic Liquid Complex Crystal

Controlling water vapor diffusion into cellulose–ionic liquid solution induced a novel cellulose complex crystal. Its unit cell consists of one glucopyranoside unit and one molecule of ionic liquid as an asymmetric unit, revealed by the results of ¹³C solid-state NMR spectroscopy. The complex crystals exhibited exceptionally large size as indicated by the narrow peak width of X-ray diffraction. This crystal reported in this work represents a new class of cellulose complexes after caustic alkali and amine complexes of cellulose. The present study is potentially significant in understanding the molecular interactions of cellulose and leads to possible applications

Cellulose Aerogel Membranes with a Tunable Nanoporous Network as a Matrix of Gel Polymer Electrolytes for Safer Lithium-Ion Batteries

Cellulose aerogel membranes (CAMs) are proposed as a matrix for gel polymer electrolyte to the fabrication of lithium-ion batteries (LIBs) with superior thermal stability. The CAMs are obtained from a celluloseionic liquid solution via a dissolution–regeneration–supercritical drying route. The presence of high porosity, the nanoporous network structure, and numerous polar hydroxyl groups benefits the quick absorption of liquid electrolytes for gelation of the CAMs and improves the ionic conductivity of the gelled CAMs. LIBs assembled with the gelled CAMs display excellent electrochemical performance at room temperature, and more importantly, the intrinsic thermal resistance of cellulose allows the LIBs to run stably for at least 30 min at working temperatures as high as 120 °C. The CAMs, with their excellent thermal stability, are promising for the development of highly safe, cost-effective, and high-performance LIBs

Rapid, Stoichiometric, Site-Specific Modification of Aldehyde-Containing Proteins Using a Tandem Knoevenagel-Intra Michael Addition Reaction

A site-specific modification of aldehyde-containing proteins using a tandem Knoevenagel-intra Michael addition reaction was developed. The reaction featured fast kinetics (50 M^–1 s^–1) and favorable stoichiometry. Various functionalities could be introduced into the protein with little impact on its function and conformation. The reaction was successfully applied in the labeling of living cells