NANOMATERIALS IN COSMETIC PREPARATIONS

This review determines various nanomaterial based cosmeceuticals. And glance on the properties, types, techniques used for preparation of nanomaterials, their advantages & disadvantages and various marketed products. Cosmeceuticals are fastest growing segment in the personal care industry and their use has increased drastically over the past years. The nanocosmeceuticals are mainly used in the application of cosmetics in managing conditions of wrinkling, dehydrated & inelastic skin associated with aging and dispersed hyperpigmentation, with the use of nanosized materials. The nanosized materials are nano emulsions, liposomes, nanosomes, dendrimers, nanocapsules and solid lipid nano particles. These nanosized materials have an advantage in increasing skin penetration and they release the active substances in a controlled and sustained manner. They have a higher stability; can be site specic targeting and high entrapment efcacy. Researchers have indicated concern regarding the impact of increased use of nanosized materials in cosmeceuticals and there are some possibilities of nanosized material can penetrate into the skin and cause health hazards.

Nanomaterials Improve Polymer-Based Gravel-Packing Fluids at High Temperature

A gravel packing fluid system was developed for elevated temperature applications above 290°F comprised of xanthan gum and a high-temperature gravel suspension additive. This fluid system has been successfully pumped in four openhole gravel packing operations so far, validating its suitability for Alternate Path gravel packing technology involving shunt tubes. Laboratory qualification testing for this fluid showed excellent gravel suspension, rheology, and breaking profiles for cleanup and minimal damage during production. Xanthan gels have been used in gravel packing applications for many years. However, by itself, xanthan was unable to suspend gravel at temperatures above 290°F possibly due to onset of thermally activated polymer degradation. This paper demonstrates that gravel suspension ability can be vastly improved with the addition of a recently developed nano-additive. This additive is a specially designed versatile nanosized material that has a proven track record with visco-elastic surfactant fluids in the past. In the present study, we show the successful application of this additive with polymer-based carrier fluids such as xanthan, effectively increasing their application range to 325°F. With the inclusion of this suspension additive, xanthan concentration in the fluid system can also be reduced, which has other potential benefits such as better cleanup after gel break. Extensive laboratory evaluation for fluid qualification was performed prior to the job. High-pressure/high-temperature (HP/HT) rheology measurements were performed using industry-standard rheometers at various shear rates to match specific viscosity requirements for shunt tube applications. Gravel suspension tests performed using special pressurized cells immersed in oil bath at the required bottomhole static temperature showed improved gravel suspension with the nano-additive. Fluid breaking with conventional oxidative breaker was also demonstrated with viscosity measurements. Formation response tests showed very good fluid cleanup with 90% regained permeability. Laboratory testing and successful field applications have proven the effectiveness of this new fluid system.

Application of Nanotechnology in Wood-Based Products Industry: A Review

Wood-based industry is one of the main drivers of economic growth in Malaysia. Forest being the source of various lignocellulosic materials has many untapped potentials that could be exploited to produce sustainable and biodegradable nanosized material that possesses very interesting features for use in wood-based industry itself or across many different application fields. Wood-based products sector could also utilise various readily available nanomaterials to enhance the performance of existing products or to create new value added products from the forest. This review highlights recent developments in nanotechnology application in the wood-based products industry.

Fibrillation and characterization of lignin-containing neutral sulphite (NS) pulps rich in hemicelluloses and anionic charge

The potential of neutral sulphite pulps from softwood with different yields (c. 58–84%) and high residual lignin contents (c. 10–25 wt%) was investigated as a raw material for lignin-containing cellulose nanofibrils (LCNFs) by following their fibrillation during grinding. It was found that the lower yield (58–65%) pulps needed two grinding cycles to produce fibrillated fibers with water retention values (WRV) as high as 400 g/g (at the energy consumption level of 1400 kWh/t). In contrast, the high yield (77–84%) pulps fibrillated more slowly, requiring five grinding cycles to reach comparable WRV values. Apparently, higher crosslinking degrees of lignin in the high yield pulps are hampering the fibrillation, although the high hemicellulose contents (21–24 wt%) and the high charge densities (200–350 µmol/g, originating from carboxylic and sulphonic acid groups) of the pulps were expected to enhance the fibrillation. Nevertheless, regardless of the different fibrillation behaviour, most of the pulps formed c. 10–15% of nanosized material below 30 nm and significant amounts of fibrils with size under 100 nm based on the centrifugation method and FE-SEM images. As the pulps were of moderate to high yield and fibrillated easily without any chemical or enzymatic pretreatments, they show promise for cost-efficient production of LCNFs. The nanopapers prepared from the fibrillated pulps showed tensile strengths (73–125 MPa) comparable with the nanopapers from high yield mechanical pulps, whereas the water contact angles (41°–58°) were closer the those of chemical pulps.

CARBON MONOXIDE ADSORPTION SEMICONDUCTOR SENSOR CREATED ON THE BASE OF THE NANOSIZED MATERIAL Pt/SnO2

Nanosized material SnO2 was obtained by a sol-gel technique to create a sensor purposed for determination of carbon monoxide concentration in air. Platinum was added to the nanosized tin dioxide by a wet impregnation method using H2PtCl6 solution. According to TEM data the average size of the SnO2 particles in the obtained nanosized tin dioxide was equal to 10–11 nm. Sensor nanomaterials based on SnO2 and Pt/SnO2 powders which were sintered at 620°C in air atmosphere consisted of spheric particles with average sizes 20 and 14–15 nm, correspondingly. Phase compositions of the obtained nanomaterials were studied by the XRD method. Only a phase of cassiterite was detected for the nanomaterials with and without platinum. The absence of any reflexes of platinum-containing phases in the diffraction pattern of Pt/SnO2 is most likely due to the low content of platinum in the material. It was shown that dopping the nanosized SnO2 materials by platinum lead to increase their catalytic activities in the reaction of CO oxidation: the temperature of practically complete conversion of CO using Pt/SnO2 catalyst was equal to 110°С. The sensor created on the base of Pt/SnO2 nanomaterial was found to be more sensitive to CO than the one created without platinum in the range of its heater power consumption 0.25–0.45 W. High catalytic activity of the Pt/SnO2 nanomaterial in the reaction of CO oxidation is a reason of such sensor sensitivity increase. The dependence of the sensitivity of the sensor on the heater power consumption has a maximum that can be explained by the change of the amount of oxygen chemisorbed on the sensor gas sensitive layer when the sensor temperature is increased. The maximal sensor sensitivity to CO is γ = 10 at the optimal heater power consumption of the sensor (0.3 W). The created sensor to CO based on the nanomaterial Pt/SnO2 was found to be very fast. The response time of the sensor (τ0,9) was equal to 4,5 sec and the relax time (τrelax) was equal to 9.8 sec. It was shown that the created sensor based on nanomaterial Pt/SnO2 has high sensitivity to carbon monoxide and possess good dynamic properties, which makes the sensor to be promising for usage it in gas analytical devices purposed for determination of CO in air.

Biomimetic insulin-imprinted polymer nanoparticles as a potential oral drug delivery system

In this study, we investigate molecularly imprinted polymers (MIPs), which form a three-dimensional image of the region at and around the active binding sites of pharmaceutically active insulin or are analogous to b cells bound to insulin. This approach was employed to create a welldefined structure within the nanospace cavities that make up functional monomers by cross-linking. The obtained MIPs exhibited a high adsorption capacity for the target insulin, which showed a significantly higher release of insulin in solution at pH 7.4 than at pH 1.2. In vivo studies on diabetic Wistar rats showed that the fast onset within 2 h is similar to subcutaneous injection with a maximum at 4 h, giving an engaged function responsible for the duration of glucose reduction for up to 24 h. These MIPs, prepared as nanosized material, may open a new horizon for oral insulin delivery.