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The possibility to discriminate between sheets of paper can be of considerable importance in questioned document examinations. 19 similar types of office paper were characterized by infrared spectroscopy and X-ray diffraction to individuate the most discriminating features that could be measured by these techniques. The discriminating value associated to them was also assessed. By using a sequence of these two techniques, all the samples could be differentiated.

Poly(lactide) (PLA) composites filled with electrospun nylon 6 fibers were prepared. This allowed us to simultaneously improve the mechanical properties and tune the degradation of the PLA matrix. The interfacial adhesion between the PLA matrix and the nylon fibers was good. The major effect of electrospun fibers on the matrix was that of modifying the semicrystalline framework, thickening the polymer lamellae. This allowed an increase in the mechanical properties of the material, and on the other hand to modify its degradation behavior. The modulus of the composites was increased up to 3-fold with respect to neat PLA. The peculiar morphology of matrix–filler interaction moreover slowed down the degradation rate of the material and improved the dimensional stability of the specimens during the degradation process. This shows the potential of electrospun fibers as a way to tune the durability of PLA-based products, widening the range of application of this promising material.

Biodegradable polycaprolactone/organoclay nanocomposites were prepared by solvent casting, using different amounts of filler and matrices differing by average molecular weight. Intercalated nanocomposites were obtained. The nanocomposites were characterized by wide‐angle X‐ray diffraction (WAXD) and small‐angle X‐ray scattering (SAXS) methods. Negligible variations in the degree of crystallinity were detected by WAXD. The thickness of crystalline lamellae, measured by SAXS, increased in low molecular weight polymer nanocomposites with increasing clay amount; this effect was weakened in matrices with high molecular weight. Differential scanning calorimetry showed an inhibiting effect of clay on crystallization. The composites' ductility was largely increased, whereas stiffness was retained. After biodegradation in compost, in all samples, the degree of crystallinity was increased, meaning that the less ordered portion of the sample was preferentially degraded. Clay slowed down the biodegradation rate, coherently with the observed increase in the lamellar thickness due to the filler. This may offer a strategy for tuning the biodegradability by calibrating their semicrystalline framework. POLYM. ENG. SCI., 2011. ©2011 Society of Plastics Engineers.

Fifty shopping bags, commonly encountered in the packaging of drug doses, were characterized by thickness measurements, infrared spectroscopy and differential scanning calorimetry. By these very straightforward and inexpensive techniques, without sample preparation, nearly all the considered samples could be discriminated. Ninety-seven percent of the possible pairs of white, apparently similar dull polymer films were differentiated. The rather large degree of variability existing in grocery bags, even though they are mass produced, was shown, confirming that these items can be useful in tracing the source of illicit drug doses.

The first examples of organic–inorganic hybrid materials reinforced by transition‐metal oxoclusters that exhibit shape memory properties, based on the covalent incorporation of zirconium‐based inorganic building blocks, are reported. Methacrylate‐functionalized zirconium oxoclusters Zr4O2(OMc)12 and [Zr6O4(OH)4(OOCCH2CH3)3OOCC(CH3)=CH29]2, with the covalent incorporation in a butyl acrylate (BA)/polycaprolactone dimethacrylate (PCLDMA) copolymer and the noncovalent incorporation of [Zr6O4(OH)4(OOCCH2CH3)12]2 are focused upon herein. Shape recovery and fixity rates are studied to observe if the shape memory properties are preserved upon going from a simple copolymer to noncovalent or covalent‐based hybrids. These rates display values higher than 90 %, which provides evidence that the oxocluster does not hinder the shape memory properties in the hybrid materials. The introduction of an inorganic phase and the progressively more stable interactions between organic and inorganic parts lead to an enhancement of the thermomechanical properties. The materials are characterized through FTIR spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and swelling tests. Dynamic–mechanical analyses are used to investigate whether the hybrid materials display thermally activated shape memory properties. The stability of the hybrid materials are evaluated by a combined spectroscopic approach based on FTIR, solid‐state NMR, and X‐ray absorption spectroscopy. Snapping back: The first example of smart hybrid shape memory materials reinforced by zirconium oxoclusters through covalent bonds is described. The observed increase in the shape recovery rate represents a proof of concept that the adopted strategy could be implemented for the preparation of shape memory hybrid materials based on covalent bonds (see figure; BA=butyl acrylate, PCLDMA=polycaprolactone dimethacrylate).

Thirty-three shopping bags, commonly encountered in the packaging of drug doses, were characterized by wide angle X-ray diffraction (WAXD). Using this single technique, without sample preparation, nearly all the considered samples could be differentiated, achieving a discriminating power of 0.992. The rather large degree of variability existing in grocery bags, even though they are mass produced, was shown, confirming that these items can be useful in tracing the source of illicit drug doses.

Absorbance peak areas of nitrile (2240 cm −1), carbonyl (1730 cm −1) and C H (1370 cm −1) groups were obtained for 48 colorless acrylic fibers by infrared (IR) microspectroscopy. The carbonyl signal, related to the comonomers most commonly used in acrylic fibers, was ratioed against the nitrile and C H bands, pertaining to the backbone of the polymer chains. The ratios A 1730/ A 2240 and A 1730/ A 1370, a relative measure of the comonomer content in the fiber, were used to differentiate the samples. A decrease in the crystallinity of fibers has been noted with increasing comonomer content. Relative standard deviation (R.S.D.) of the ratios were 1 and 3% for repetitive analyses on the same location and along the length of the same single fiber, respectively. When different fibers of the same sample were examined, results were reproducible within 6%. This simple method can greatly enhance the evidential value of colorless acrylic fibers, being able to discriminate them and thus helping the Court to better assess their significance.

Latex gloves are quite frequently employed by felons, when committing crimes, if they want to avoid shedding fingerprints or biological traces. Less forensic aware crime committers, though, may discard the gloves at the crime scene or nearby. If found and properly analyzed, these items may therefore provide useful information to investigators. An analytical procedure of such items is proposed, using thermogravimetry and differential scanning calorimetry. By these very straightforward and inexpensive techniques, without sample preparation, nearly all the considered samples could be discriminated. 99.5% of the possible pairs of latex gloves, indistinguishable by visual examination, were differentiated. The rather large degree of variability existing in latex gloves, even though they are mass produced, was shown, confirming that these items can be useful in comparisons between items related to the crime scene and those seized in the suspect's premises.

Fiber evidence found on a suspect vehicle was the only useful trace to reconstruct the dynamics of the transportation of two corpses. Optical microscopy, UV-Vis microspectrophotometry and infrared analysis were employed to compare fibers recovered in the trunk of a car to those of the blankets composing the wrapping in which the victims had been hidden. A “pseudo-1:1” taping permitted to reconstruct the spatial distribution of the traces and to further strengthen the support to one of the hypotheses. The Likelihood Ratio (LR) was calculated, in order to quantify the support given by forensic evidence to the explanations proposed. A generalization of the Likelihood Ratio equation to cases analogous to this has been derived. Fibers were the only traces that helped in the corroboration of the crime scenario, being absent any DNA, fingerprints and ballistic evidence.

The refractive index (RI) of 40 colorless acrylic fiber samples was determined by the immersion oil and Mettler hot stage method, implemented in the glass refractive index measurement (GRIM) instrument by Foster and Freeman. Low standard deviations for nearly all the samples were obtained and differentiation of fibers even with the same trade name was possible just on the basis of RI. Wide angle X-ray scattering (WAXS) and differential scanning calorimetry (DSC) were employed to establish a linear correlation between RI and the degree of crystallinity. Insights on the structural order of this group of fibers is then obtainable by a quick and easy technique, adding value to casework comparisons.